The Fungous Diseases of Man [2nd printing, Reprint 2020 ed.] 9780520308947

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The fungous diseases of man

The fungous diseases of man J. W A L T E R WILSON,

M.D.

Clinical Professor of Medicine (Dermatology), University of California, Los Angeles, and Chief of Dermatology, Long Beach Veterans Hospital, Long Beach, California

ORDA A. P L U N K E T T ,

PH.D.

Professor Emeritus of Botany (Mycology) and Research Professor, Department of Dermatology, University of California, Los Angeles

University of California Press BERKELEY AND LOS ANGELES

1967

University of California Press Berkeley and Los Angeles Cambridge University Press London, England © 1965 by The Regents of the University of California All Rights Reserved Library of Congress Catalog Card Number: 65-23461 Second Printing, 1967 Designed by Betty Binns Printed in the United States of America Color Plates Printed in Switzerland

Preface

last thirty years the field of medical mycology has been reasonably well covered in a series of textbooks, listed at the end of the Preface. Although appearing with ever-increasing frequency, these books have recently been published somewhat too far apart to keep pace with a rapidly advancing state of factual knowledge. It was not from a desire to fill any such quantitative deficiency, however, that the impetus to write the present volume was drawn. The principal motivating factor was the ever-growing conviction that good fortune had provided us with excellent opportunities to study and acquire experience concerning fungous diseases, perhaps affording some elements of value which we should attempt to make available to others. We now realize that we have matured about as much as our life spans will permit, and that, if we are ever to make any more contributions, we had better "be about it." DURING T H E

It has long been evident that the best understanding of a microbial disease could be gained only through close collaboration between clinicians and persons expert in laboratory technical procedures. We formed such a team more than twenty years ago, after each of us had spent almost an equal time span in his chosen profession. The combination of a clinical dermatologist possessing an exceptional interest in the laboratory phases of mycology, and a cryptogamic botanist deeply interested in human fungous diseases, has accomplished much more than either of them could have done alone. Another tremendous advantage we have enjoyed has been a betterthan-average opportunity to learn to know the persons interested in medical mycology, not only in our own country, but in many parts of v

vi

Preface

the world, first through correspondence, and later by frequent personal visits, either by us or to us. The importance of this asset is that many fungous diseases are rather sharply limited to one geographic region, making it impossible for any one person to acquire enough personal experience to write authoritatively about all such diseases. Two especially good examples of this form of collaboration deserve mention. Late in i960, one of us (J. Walter Wilson) was asked to write a paper on "The Therapy of Systemic Fungous Infections" for publication in the AMA Archives of Internal Medicine. The ensuing correspondence made it clear that one person could not possibly write such a paper from his own experience alone. Because of geographic limitations he could speak authoritatively on only one or two such diseases; he would need to seek for the rest of the material in the literature, and hence that part of his article would be hopelessly out of date. The result was a symposium. Contributions were solicited for February 1, 1961, from twenty carefully selected collaborators, each of whom was a renowned expert in one or more of these diseases. All these authorities responded on time, the material was edited as compactly as possible within a month, and the symposium appeared in print in August, 1961. Participating in the symposium were the following persons, whose inestimable help is once again gratefully acknowledged: Peter Abbott, Teheran, Iran; Gerald L. Baum, Cincinnati, Ohio; Guillermo Fernández Baquero, Havana, Cuba; Arturo L. Carrión, San Juan, Puerto Rico; Norman F. Conant, Durham, North Carolina; Arthur C. Curtís, Ann Arbor, Michigan; Sharat C. Desai, Bombay, India; Michael L. Furcolow, Kansas City, Kansas; Antar Padilha-Gonsalves, Rio de Janeiro, Brazil; Antonio González-Ochoa, Mexico City; E. Richard Harrell, Ann Arbor, Michigan; John H. Lamb, Oklahoma City, Oklahoma; Fernando Latapí, Mexico City; M. L. Littman, New York; Donald B. Louria, New York; Pablo Negroni, Buenos Aires, Argentina; Victor D. Newcomer, Los Angeles, California; Sebastiao Sampaio, Sao Paulo, Brazil; Francisco Scannone, Caracas, Venezuela; Jan Schwarz, Cincinnati, Ohio; Charles E. Smith, Berkeley, California; William A. Winn, Springville, California. The opinions of these experts have been incorporated even more recently into the present volume, and some paragraphs have been reproduced here through the courtesy of the AMA Archives of Internal Medicine. The second example of collaboration is the Symposium on Immunologic Aspects of Fungous Diseases held as a part of the Twelfth International Congress of Dermatology in Washington, D.C., in September, 1962. Nine similar authorities participated in this symposium, each in his own chosen field: Antar Padilha-Gon9alves, Michael L. Furcolow, Sebastiao Sampaio, Norman F. Conant, A. Salazar Leite, Antonio González-Ochoa, Pablo Negroni, Sharat C. Desai, and Kasuke Ito, from

Preface

vii

whose contributions some of our text has been taken. Credit is also owed to Donald M. Pillsbury and Clarence S. Livingood, editors of the proceedings of the Congress, and to the publishers, the Exerpta Medical Foundation of Amsterdam. One of our strongest inducements to complete this task was the opportunity to illustrate the volume largely in color. Color illustration has never before been practical because of its prohibitive expense, particularly for a volume likely to have only a limited sale. The generous collaboration of three pharmaceutical companies, each interested in antifungal drugs far beyond the usual profit motive, has made such illustration possible. About six years ago we were asked by F. Hoffmann La Roche, Ltd., Basel, Switzerland, through Dr. J. R. Frey, to assemble photographs in color adequate to serve as illustrations for a series of pamphlets, each devoted to one of the systemic or deep mycoses, and intended for use in the dissemination of knowledge about such diseases. Individual pictures, selected for excellence in teaching value, were solicited from many foreign countries as well as from numerous colleagues in the United States, and the response was very gratifying. We hereby gratefully acknowledge such contributions from Sharat C. Desai, Bombay; Pablo Negroni and Flavio Niño of Buenos Aires; Joào Aguiar Pupo, Sebastiào Sampaio, Floriano P. de Almeida, and Carlos da Silva Lacaz of Sao Paulo, Brazil; Joáo Ramos e Silva, Antar Padilha-Gon^alves, José Lisboa Miranda, and Area Leào of Rio de Janeiro; Tancredo A. Furtado of Belo Horizonte, Brazil; Francisco Scannone, Francisco KerdelVegas, Jacinto Convit, and Dante Borelli of Caracas, Venezuela; Arturo Tapia of Panama; Antonio González-Ochoa, Fernando Latapi, and Pedro Lavalle of Mexico; and Guillermo Fernández Baquero and Francisco Trespalacios of Cuba. Other fine pictures were received from colleagues in the United States through the courtesy of Arthur C. Curtis and E. Richard Harrell of Ann Arbor, Michigan; Vicente Pardo Castellò of Miami, Florida; Edward A. Oliver, Herbert Rattner, and Samuel M. Bluefarb of Chicago; Chester W. Emmons of Washington, D.C.; Morris Moore of St. Louis, Missouri; Norman F. Conant of Durham, North Carolina; Fred D. Weidman of Philadelphia; Michael L. Furcolow of Kansas City, Kansas; Lucille K. Georg of Atlanta, Georgia; Leslie M. Smith and Henry Garrett of El Paso, Texas; John H. Lamb and Rollin Koons of Oklahoma City, Oklahoma; and Carlyn Halde of San Francisco. These pictures, in the form of transparencies, were assembled into thirty-two composite plates by Avis Gregersen, F.B.P.A., of the University of Southern California School of Medicine. When griseofulvin was discovered by J. C. Gentles of Glasgow, we became active in its evaluation and in instruction in its use, in collaboration with the Schering Corporation of Bloomfield, New Jersey. Through the generosity of this company twelve plates were prepared

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Preface

to illustrate the superficial fungous infections, and ten were prepared to show the gross appearance of colonies of all the fungi pathogenic for man, together with the most common contaminants likely to be encountered by the medical mycologist. The selection of components and the composition of these plates were also the work of Avis Gregersen. Finally, Glaxo Laboratories of Greenford, Middlesex, England, provided funds for the actual printing of these plates onto paper, another excellent example of international collaboration among Switzerland, England, and the United States. Without such cooperation this volume would never have appeared. Additional illustrations not in color were gratefully received from Carlyn Halde of San Francisco, Harry Van Velsor of Wilmington, North Carolina, and Frances Keddie of Los Angeles. Radiographs of the deep mycoses were contributed from the files of the Los Angeles County General Hospital through the courtesy of George Jacobson, who also wrote the legends for them. We are greatly indebted to Roy H. Wishard of Los Angeles for the diagrammatic drawings illustrating the characteristics of the fungi and their life cycles. The photomicrographs of fungi have been contributed by Lily Clark Davis of Los Angeles. Frank E. Swatek assisted in several phases of mycology. We gratefully acknowledge permission from Charles C Thomas Publishers to utilize sections of the volume, Clinical and Immunologic Aspects of Fungous Diseases, by J . Walter Wilson, as part of the framework of the present volume. We are indebted to the editors of the AMA Archives of Dermatology (Walter C. Lobitz, chief editor) and to the American Medical Association for permission to quote from some of our own recent papers published therein. Finally, the tedious labor of typing and retyping the manuscript several times was done, not only swiftly and indefatigably, but with an unusual degree of accuracy and excellence, by Doris Gihon and Marie C. Plunkett, without whose enthusiastic support the task would never have been finished. J . W. W. O. A. P.

Bibliography Ajello, L., L. K. Georg, W. Kaplan, and L. Kaufman. 1963. Laboratory manual for medical mycology. U.S. Department of Health, Education, and Welfare. Communicable Diseases Center, Atlanta, Ga. Public Health Serv. Publ. no. 994Conant, N. F., D. S. Martin, D. T . Smith, R. D. Baker, and J..L. Callaway. 1944. Manual of clinical mycology. 2d ed., 1954. Philadelphia and London: W. B. Saunders Co. Emmons, C. W., C. H. Binford, and J. P. Utz. 1963. Medical mycology. Philadelphia: Lea & Febiger. Gohar, N. 1948. Mycoses and practical mycology. Baltimore: Williams 8c Wilkins Co. Lacaz, C. da S. 1953. Manual de micologia medica. 2d ed., 1956; 3d ed., i960. Rio de Janeiro and Säo Paulo: Livraria Atheneu S/A. Langeron, M., and R. van Breuseghem. 1952. Précis de micologie. 2d ed. Paris: Masson. Lewis, G. M., and M. E. Hopper. 1939. An introduction to medical mycology. 2d ed., 1943; 3d ed., 1948. Chicago: Year Book Medical Publishers. Lewis, G. M., M. E. Hopper, J. W. Wilson, and O. A. Plunkett. 1958. An introduction to medical mycology. 4th ed. Chicago: Year Book Medical Publishers. Moss, E. S., and A. L. McQuown. 1953. Atlas of medical mycology. Baltimore: Williams 8c Wilkins Co. 192 pp. Skinner, C. E., C. W. Emmons, and H. M. Tsuchiya, revisers. 1947. Molds, yeasts, and actinomycetes, by A. T. Henrici. 2d ed. New York: John Wiley 8c Sons. Van Breuseghem, R. 1958. Mycoses of man and animals. Trans. J. Wilkinson. Springfield, III.: Charles C Thomas. Wilson, J. W. 1957. Clinical and immunologic aspects of fungous diseases. Springfield, 111.: Charles C Thomas.

Contents

Introduction PART

PART

1

I The Systemic Mycoses 1 Comparative Pathogenesis

7

2 Comparative Immunologic Aspects

13

3 Therapeutic Aspects

19

4 Coccidioidomycosis

25

5 Sporotrichosis

49

6 Histoplasmosis

64

7 North American Blastomycosis

84

8 South American Blastomycosis (Paracoccidioidomycosis)

101

9 Cryptococcosis

111

10 Actinomycosis

130

11 Nocardiosis

143

12 Mycetoma

150

II The Intermediate Mycoses 13 Candidiasis (Moniliasis)

165

14 Chromoblastomycosis

179 xi

xii

PART

PART

Contents 15 Phycomycosis (Mucormycosis)

189

16 Aspergillosis

197

17 Rhinosporidiosis

205

III The Superficial Mycoses 18 Dermatophytosis

213

19 Tinea Versicolor

252

20 Tinea Nigra

259

21 Piedra

264

22 Miscellaneous Superficial Disorders Sometimes Attributed to Fungi

268

23 Mycoses of the Eye

272

24 Fungi as Occupational Hazards

275

IV Fundamentals of Medical Mycology 25 Morphology of Fungi

281

26 Nutrition of Fungi

293

27 Variation, Pleomorphism, and Dimorphism in Pathogenic Fungi

297

28 Classification of Fungi

308

29 Identification of Fungi of Importance in Medical Mycology 314 30 Laboratory Methods of Diagnosis Glossary Index

392 413 421

Illustrations

COLOR PLATES following page 30

1 Coccidioidomycosis: nondisseminated type 2 Coccidioidomycosis: disseminated type 3 Coccidioidomycosis: disseminated type 4 following

5 6 7 8 9 10 11 12 following

Coccidioidomycosis: histopathology and appearance in culture page

54

Sporotrichosis: primary cutaneous (chancriform) syndrome Sporotrichosis: primary cutaneous (chancriform) syndrome Sporotrichosis: verrucous and aberrant types Sporotrichosis: histopathology and appearance in culture Histoplasmosis: lesions of the tongue Histoplasmosis: other mucous membrane lesions Histoplasmosis: cutaneous lesions and histopathology Histoplasmosis: histopathology and cultural characteristics page

94

13 North American blastomycosis: chronic cutaneous form 14 North American blastomycosis: chronic cutaneous form 15 North American blastomycosis: cutaneous lesions and histopathology 16 North American blastomycosis: histopathology and cultural characteristics 17 South American blastomycosis (paracoccidioidomycosis): cutaneous lesions on face xiii

xiv

Illustrations

following page 94

18 19 20

South American blastomycosis: ulceroglandular form; Jorge Lobo's disease South American blastomycosis: histopathology South American blastomycosis: histopathology and cultural characteristics

following page 1)4

21 22 23 24 25 26 27

Cryptococcosis: Cryptococcosis: Cryptococcosis: Cryptococcosis: Actinomycosis: Actinomycosis sions Actinomycosis characteristics

cutaneous lesions cutaneous lesions histopathology histopathology and cultural characteristics cervicofacial type and nocardiosis: neck, hand, and back leand nocardiosis: histopathology and cultural

following page 158

28 29 30 31

Mycetoma (maduromycosis): clinical and mycologic aspects Mycetoma: clinical and histopathologic aspects Candidiasis (moniliasis): cutaneous lesions Moniliasis, aspergillosis, and rhinosporidiosis: histopathology

following page 190

32 33

Chromoblastomycosis: clinical forms Chromoblastomycosis: clinical forms and histopathology

following page 222

34 35 36 37 38 39 40 41 42 43 44

Tinea capitis: noninflammatory (human) type Tinea capitis: inflammatory (animal) type Tinea capitis: black-dot type and favus Tinea barbae and trichophytic (Majocchi's) granuloma Tinea corporis Tinea cruris Tinea pedum and manuum: chronic, hyperkeratotic, mildly inflammatory type Tinea pedum and manuum: acute, highly inflammatory type Tinea of the nails (onychomycosis) Dermatophytid reactions Tinea versicolor and erythrasma

following page 318

45 46 47

Colonies Colonies pycnidia Colonies

of Phycomycetes and Plectomycetes of Pyrenomycetes: fungi producing perithecia and and yeastlike fungi of Candidioideae, Arthrosporeae, and Cephalosporeae

Illustrations

xv

following page 318

48 49 50 51 52 53 54

Colonies of Aspergillaceae, Aspergillus, and Pénicillium, Colonies of Aspergillaceae, Botrytideae, and Aleuriosporeae Colonies of Aleuriosporeae, Verticilleae, and Actinomyceteae Front and reverse of colonies of Trichophyton species Front and reverse of colonies of dermatophytes Colonies of Dematiaceae Colonies of Dematiaceae, Stilbaceae, and Tuberculariaceae

FIGURES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Coccidioidomycosis: dissemination in lungs, 31 Coccidioidomycosis: lesion in metatarsal bone, 32 Coccidioidomycosis: involvement of vertebral body, 33 Histoplasmosis: pulmonary calcifications, 68 North American blastomycosis: infiltration in lungs, 89 Cryptococcosis: consolidation in lung, 115 Cryptococcosis: extensive destruction of right lung, 116 Cryptococcosis of tibia, 119 Actinomycosis: destruction of acromion process and articular cartilage of acromioclavicular joint, 133 Actinomycosis: destruction of ramus and body of left mandible, 134 Aspergillosis: fungus ball, 200 Aspergillosis: osteomyelitis of ulna, 201 Tinea imbricata, 223 Malassezia furfur (Pityrosporum orbicularef), causative organism of tinea versicolor, 256 Tinea nigra, 261 Somatic structures, 282 Thallospores, 284 Endogenous asexual spores, 285 Conidia and conidiophores, 286 Asexual fruiting bodies, 287 Sexual spores of Phycomycetes, 288 Sexual fruiting bodies of Ascomycetes with asci and ascospores, 290 Sexual spores of Basidiomycetes, 291 Dimorphism in Coccidioides immitis, 301 Dimorphism in Histoplasma capsulatum, 302 Dimorphism in Chrysosporium (Blastomyces) dermatitidis, 303 Dimorphism in Chrysosporium (Haplosporangium) (Emmonsia) parvum and Sporotrichum schenckii, 305 A classification of fungi of importance in medical mycology, 311

Illustrations

xvi 29 30 31 32 33

Macroconidia of six Microsporum species, 371 Bottle recommended for office culture of fungi, 395 Technique of inoculation of cultures, 397 Hinged wall cabinet for storing cultures, 398 Technique for easy inspection of cultures during growth, 399

Introduction

as applied to the study of the cause of disease in plants and animals is the oldest of the microbiological sciences. Far back in antiquity, it was realized that disease was often attributable to parasites that were visible to the naked eye, and with the passage of time it was increasingly believed that forms of life too small to be thus visible were often equally responsible. For want of more detailed factual knowledge, the causes of disease were vaguely referred to as "humors" or "bad air," in a manner reminiscent of that used until quite recently, before the clarifying advent of the electron microscope, in discussing the group of etiologic agents known as filterable viruses. MYCOLOGY

Not surprisingly, therefore, soon after the discovery that the acuity of the naked eye could be markedly extended by artificial magnifying lenses, such instruments were directed toward the discovery of tiny plant parasites. In 1677, by using the crude hand lenses available at that time, Hooke was able to point out that the disease occurring as yellow spots on rose leaves actually consisted of tiny threads of a living parasitic plant. In 1835 Bassi discovered that a disease of silkworms known as muscardine was caused by a fungus (Beauvaria bassiana), thus proving that plants could parasitize forms of animal life. Shortly thereafter, in 1839, Schoenlein demonstrated, by discovering the organism causing favus, that a fungus could be the etiological factor in human disease, and three years later Remak reproduced the disease in animals and in himself. Gruby accomplished the same feat independently at about the same time, and succeeded in culturing the causative fungus on artificial media by inoculating specimens taken from the sites of the original infection. He then 1

2

Introduction

reproduced the disease by inoculating such culture material onto the areas of intact skin of patients possessing the disease, as well as on normal persons. Gruby thereby fulfilled what later became unjustifiably famous as Koch's postulates, comprising the criteria necessary for the acceptance of a microbe as the cause of a specific disease. In the succeeding three decades a number of other fungi, such as several species of Microsporum and Trichophyton and those now known as Candida albicans and Malassezia furfur, were proved to be the cause of human skin disease. T h e first discovery that there were systemic or deep fungal infections was Bollinger's identification of actinomycosis (lumpy jaw) in cattle in 1877, almost simultaneously with Ponfick's delineation of the equivalent disease in human beings. In contrast with all the above, the science of bacteriology did not begin until the monumental work of Koch in 1876, and that of Pasteur on anthrax in 1877. In spite of its early precedence, medical mycology was soon far outdistanced by bacteriology and other similar sciences in popularity and scope. Not until R. Sabouraud's monumental work, Les Teignes, was published in 1910 was any noticeable momentum gained, and only during the last two decades has knowledge of mycology been extensively disseminated. Perhaps the principal reason for such delay lies in the fact that no fungous disease is both dangerous to life and of common occurrence, whereas several of the diseases caused by bacteria, such as plague, cholera, and typhoid fever, formerly killed so many persons yearly that veritable crusades were organized against them. T h e study of fungi and the diseases they produce could not be expected to attract adequate personnel until at least the easily discoverable answers about such scourges were known. It is difficult, however, to resist the temptation to point out that the subjugation of mycology to bacteriology almost certainly deprived the former science of many workers, some of whom might have discovered penicillin and streptomycin in less than the hundred years that history must record. T h e entire heavy-metal phase of the therapy of syphilis might have been avoided. Nevertheless, even with such handicaps, medical mycology slowly but steadily grew in stature. Between 1892, when coccidioidomycosis was discovered by Posadas and Wernicke, and 1908, when Lutz delineated South American blastomycosis, the causative organisms were firmly established for North American blastomycosis (1894), cryptococcosis (1895), sporotrichosis (1898), nocardiosis (1895, and perhaps as early as 1890), and histoplasmosis (1906). T h e greatest of all mycologically oriented dermatologists was Sabouraud, who began writing in 1892. He completed his first book, Les Trichophyties humaines, in 1894, and his twelfth in 1938. T h e fifth book in the series (the third directed toward diseases of the scalp) was Les Teignes (1910), a veritable bible for workers concerned with derma-

Introduction

3

tophytes. In 1908 Whitfield established that some types of foot disease are caused by fungi, and discovered the ointment that bears his name by treating his own infection. In 1902 trichophytin was isolated by Plato and Neisser, who called attention to the reaction it could elicit when used on some patients infected with dermatophytes. This remedy was developed much further by Bloch in 1928. In 1925 Margarot and Deveze discovered the phenomenon of fluorescence of hairs infected by Microsporum when viewed under ultraviolet radiation (Wood's light). Several factors that retarded the progress of mycology deserve discussion, principally because it is not generally realized that fungous diseases are now so easily controllable that any practitioner can acquire whatever degree of mycological knowledge he may find of practical value in his chosen field. T h e complicated nomenclature and classification have been greatly simplified; the delineation betweeen pathogenic and nonpathogenic organisms has been clarified; and simple, practical methods have been evolved for direct examination of tissues, for culture and identification of organisms, and for preservation of specimens of value in teaching. Differentiation between disorders of fungous and nonfungous origin on clinical grounds alone is highly inaccurate. This deficiency always becomes apparent whenever a community acquires for the first time the services of a practitioner interested in mycology; occasionally his laboratory work reveals faulty diagnosis by the most experienced clinicians, and, more often, by those less qualified. After mycological study, better treatment schedules may be selected and a much more accurate prognosis may be made. It is easier to gain and hold the patient's confidence if scientific mycological methods are employed. Depending on whether certain fungi are classed as separate species or considered as variants within a species, approximately fifty species of fungi are capable of causing human disease. T h e resulting clinical syndromes are extremely variable. Some are encountered frequently; others are met very rarely. Some are closely confined to a certain geographic locality, while others are universally distributed. Some are so superficial that the patient is unaware of any abnormality, but others may lead to extensive systemic involvement ending in death. Some fungi are so highly pathogenic and they probably can cause actual infection in all adequately exposed persons; others, called opportunistic fungi, do so only if presented with abnormal human tissues, either localized in certain areas of the body, or generalized because of systemic disease. T h e rest of the many thousands of species of fungi in the world never cause human disease under any circumstances, although many are parasites on plants. By strict definition, the title The Fungous Diseases of Man might be expected to include certain toxic conditions caused by the ingestion

4

Introduction

of fungi, such as the gangrene of ergotism (Cluviceps purpurea), the hallucinations of Psylocybe, the poisoning effects of certain mushrooms (Amanita, etc.), the occasional undesirable side effects of the otherwise extremely valuable antibiotics derived from fungi, and perhaps even acute and chronic alcoholism (Saccharomyces cereviseae). This book, however, is devoted only to actual infections caused by fungi in the human species. In the overall view, fungi cause man more satisfaction than trouble. They raise his bread, ferment his wine and beer, carbonate his champagne, flavor his cheeses, furnish him edible mushrooms, produce drugs to stop bleeding, work diligently to form antibiotics to help him fight bacterial and fungal infections, and help industry to produce many organic acids and other compounds. T o the cryptogamic botanist they are even beautiful to behold, and their unending variation is fascinating.

I

Comparative pathogenesis

in man are capable of causing so wide a variety of clinical pictures that it is always wise to include them in the differential diagnosis of almost any disease, with the possible exception of certain acute surgical or medical emergencies. In fact, it has been customary to emphasize so strongly the differences among the disorders produced by various species of fungi that certain fundamental similarities, potentially of even more significance, were relegated into obscurity, or, in fact, failed to be recognized at all until recently. It is obvious that numerous factors are capable of influencing the pathologic picture that emerges from a certain infection. A tiger will starve to death rather than make any attempt to eat grass, and a cow shows the same reaction if presented with nothing to eat except living animals. We must recognize that in their pathogenic phases different species of fungi are similarly very particular about their diet, although not quite so exclusively as in the above example. Histoplasma capsulatum prefers to live within the cells of the reticuloendothelial sysFUNGOUS INFECTIONS

7

8

The systemic mycoses

tem; Cryptococcus neoformans has a predilection for the tissue of the central nervous system of susceptible persons; Blastomyces dermatitidis especially likes the skin; Paracoccidioides brasiliensis prefers mucous membranes and lymph glands. The dermatophytes luxuriate in the keratin of skin, hair, and nails, but Malassezia furfur limits its diet to the keratin of the skin. Thus, if each of these fungi was contacted by identical human beings in exactly the same manner, the resulting diseases could not even remotely be expected to produce the same clinical picture. Some fungi are so highly pathogenic that they are probably capable of causing disease in all adequately exposed persons, whereas others invade only tissues presenting an abnormally low resistance. Many factors inherent in the characteristics of the host, even if all other factors are equal, therefore influence the outcome. Age, sex, race, skin color, state of health, and nutrition bring about tremendous variations. Some fungi cause disease only in certain localized areas or tissues, but others create significant differences in clinical syndromes by becoming widely disseminated through the bloodstream and finding certain regions less resistant than others (though not consistently the same regions in different persons). Variations are also characteristic of the progressive stages of some infections. If all factors are taken into consideration, interesting similarities may be found among fungous diseases that at first glance appear to be totally different. One of the most neglected factors is determination of the portal of entry of the fungus in infections that are capable of becoming systemically widespread. Formerly, if a fungous infection was first observed as a lesion in the skin, it was concluded that the causative organisms had been inoculated at that point. The wide differences in the appearance and the clinical course of the cutaneous lesions of different deep mycoses were attributed entirely to variations in the activities of the different fungi. Although this explanation is undoubtedly true to a certain extent, it does not account for all the differences, some of which are owing to the manner and locality of the inoculation, while others result from the efforts of the host to resist the disease. Thus, we have not always been certain that we were comparing these diseases in similar stages. For example, until about ten years ago it was accepted as fact that the inoculation into the skin of three different species of pathogenic fungi routinely caused three different clinical pictures. It was thought that Sporotrichum schenckii produced a chancriform syndrome, characterized by an initial ulcerative nodule at the inoculation site, lymphangitis with nodules along the lymphatic vessels draining the area, and mild regional lymphadenopathy, the entire pathologic process almost always remaining limited to this region; that Coccidioides immitis caused a subcutaneous abscess, whence the infection spread by hematogenous dissemination throughout the body; and that Blastomyces dermatitidis, when similarly inoculated, resulted in a chronic, verrucous skin disorder, slowly spread-

Comparative pathogenesis

9

ing peripherally and superficially for many years, but practically never disseminating internally. These discrepancies were partly resolved by the discovery of several cases in which Coccidioides or B. dermatitidis, known beyond a doubt to have been inoculated into the skin, produced a chancriform syndrome practically identical with that usually seen in sporotrichosis. T h e original case of primary cutaneous chancriform coccidioidomycosis, reported in 1953 by Wilson, Smith, and Plunkett, was soon confirmed by another case observed by Trimble and Doucette, and later by still another presented by Wright and Newcomer. Winn has observed three more such cases. Keith Maddy has furnished details of three chancriform cases in dogs, which became infected by inoculations into injuries in their paws while digging in animal burrows contaminated by Coccidioides. T h e status of primary cutaneous chancriform North American blastomycosis still rests on the reports of Schwarz and Baum and of Wilson, Cawley, Weidman, and Gilmer, totaling four cases. Although few in number, these cases were definitely known to have been intracutaneously inoculated. T h e study of them has led to the conclusion, supported by ever-increasing evidence, that many, if not all, of the other cases of these two diseases in which the initial lesion appeared in the skin were nevertheless not caused by inoculation at that point, but by dissemination from a previously unrecognized or subclinical primary infection elsewhere in the body, usually the lungs. Curtis and Harrell have reported a case of histoplasmosis which followed the same chancriform pattern, as also have Tosh and Furcolow. Baumgarten has described a case clinically like the usual form of lymphatic sporotrichosis, except that Nocardia asteroides was the organism recovered by culture. Alarcon, Obadia, and Borelli have reported a similar case caused by N. brasiliensis. In 1927 Guy and Jacob reported a chancriform syndrome caused by Nocardia; the species was not identified. T h e chancriform syndrome has thus been observed, with little variation in the clinical picture, in infections resulting from six different species of pathogenic fungi when intracutaneously inoculated. In addition, and again with only slight variations, this picture is also well established as the expected result when several other species of microorganisms result in disease by intracutaneous inoculation, particularly those causing tuberculosis, syphilis, American leishmaniasis, and yaws. T h e chancriform syndrome, however, has not been reported to have occurred in some of the remaining deep mycoses, notably cryptococcosis, actinomycosis, maduromycosis, South American blastomycosis, and chromoblastomycosis. In some diseases, it is probable that the chancriform syndrome never occurs, while it may do so in others, but only under special obligatory circumstances. Clearly the first of these circumstances is that the organisms must be acquired by direct inoculation through the skin by means of a wound.

10

The systemic mycoses

We know the source in nature from which the organisms that cause sporotrichosis, coccidioidomycosis, and histoplasmosis are obtained, and hence we have a clue as to how frequently intracutaneous inoculations may be expected to occur. Sporotrichum grows as a closely adherent moist mat on plants and wood which can furnish thorns and splinters capable of inflicting wounds and leaving therein fragments containing many fungal spores. Conversely, Coccidioides and Histoplasma grow in soil as fluffy mats, with spores so lightly attached and fragile as to blow away in the slightest breeze; it is easy to understand why they are seldom inoculated in any large quantity through the skin, but are almost universally acquired by inhalation. The source in nature of B. dermatitidis was obscure until very recently, when Ajello recovered it from soil. If his finding is confirmed, it will place this organism in line with Coccidioides and Histoplasma. Cryptococcus neoformans also grows in soil, particularly that contaminated by fecal material from birds and fowl. Some of the species of Nocardia and Streptomyces and the organisms of mycetoma are also soil organisms. All these may behave as Coccidioides and Histoplasma do, and thus may seldom be intracutaneously inoculated. The source in nature for Paracoccidioides brasiliensis is not known, nor has it been proved for the fungi that cause chromoblastomycosis, although species closely similar to these latter are known to grow on dead vegetation from which intracutaneous inoculation could certainly occur. It is not enough, however, to speculate only on whether or not cutaneous inoculation can occur; we must also consider what happens when it does. The chancriform syndrome is characterized by initial multiplication of the fungal organisms at the site for a brief period, probably only a few days. Then a specific immunologic resistance of the host begins to develop, soon causing an intense infiltration of leucocytes and marked induration and inflammation. The regional lymphatic system becomes involved in this inflammatory process. Immediately the concentration of fungal organisms begins to decrease, and soon they are present in numbers so small that usually they are discernible in histopathologic preparations only by searching carefully through several slides. It has long been known that in sporotrichosis the organisms are too small and sparse to be found in the affected tissues by histologic study, although they are easily cultured. Fetter has recently succeeded in revealing them; but they are so sparse that previous digestion of all polysaccharide material not of fungal origin, followed by intensive periodic acid-Schiff (PAS) staining, is necessary to find them. Similarly, in chancriform histoplasmosis the causative organisms have not been discoverable in the tissues, because they are also very small. These organisms could, however, be found in this stage of coccidioidomycosis and blastomycosis because they are large and easily seen, even though present in very small numbers.

Comparative pathogenesis

11

In several microbial diseases, such as malaria and trypanosomiasis, the causative organisms are inoculated through the skin without necessarily producing any lesion at that point. Hence the chancriform syndrome is almost entirely the result of that which the host contributes to the clinical picture in resisting the disease, and it can therefore develop only if the invasion is resisted locally by systemic immunologic means to a fairly high degree. In the chancriform cases of coccidioidomycosis, North American blastomycosis, and histoplasmosis thus far recorded, the resistance has been sufficiently strong to result in complete, spontaneous cure. In sporotrichosis it is usually not quite so effective, as evidenced by the fact that this disease tends to persist if untreated. It is, however, at a sufficiently high level to keep the infection limited to a single limb, and to furnish so much immunologic assistance that cures have been obtained, not only regularly by the favored potassium iodide, but at times by many other drugs, including griseofulvin, amphotericin B, stilbamidine, sulfonamides, and antimalarials. All these remedies fail miserably when pitted against other deep mycoses, and indeed against sporotrichosis in its more dangerous, less well-resisted phases. This fact may explain the failure of the chancriform syndrome to occur in Cryptococcus infections. This organism is apparently not in the slightest degree pathogenic for normal persons, and those abnormal ones who do become infected usually do not resist the invasion to any degree by immunologic means, certainly not to the extent necessary to produce the chancriform syndrome. Baquero reports some evidence that the usual chronic cutaneous form of chromoblastomycosis, formerly assumed to have originated by direct cutaneous inoculation, may in reality occur by dissemination from a previously unrecognized primary pulmonary focus. Such dissemination is now widely believed to occur in North American blastomycosis and coccidioidomycosis. Such variations as these lead to speculation that, if the chancriform syndrome is to appear, the individual must not have been previously infected by the organism. Perhaps intracutaneous inoculation of an appropriate fungus cannot produce the syndrome if the recipient has been previously infected by the same organism via another route, and therefore altered in his capacity to react allergically or immunologically to subsequent exposures. It is even possible that this alteration may be produced by allergic means through the inhalation, not of the specific pathogenic fungi, but of nonpathogenic fungi closely allied to them.

Bibliography Convit, J., D. Borelli, R. Albornoz, G. Rodriguez, and J . Homez. 1961. Mycetoma, chromomycosis, sporotrichosis, and Jorge Lobo's disease, [In Spanish.] Mycopathologia, 15:394.

12

The systemic mycoses

Littman, M. L. 1959. T h e systematic mycoses. Amer. J. Med., 27:1. MacKinnon, J . E. 1959. Revisión critica de la investigación y de la literatura micològica en el Uruguay en el periodo 1946-1956. Mycopathologia, 9:692. Pillsbury, D. M., and A. M. Kligman. 1951. A new histo-chemical tool for the definitive diagnosis of fungous infections. Trans. N.Y. Acad. Sci., 2d ser., 13:145. Wilson, J. W. 1956. Comparative pathogenesis of the deep mycoses: the influence of the port of entry. In F. R. Schmidt, ed., Clinical selections in dermatology and mycology, P. 113. Springfield, 111.: Charles C Thomas. . 1957. Clinical and immunologic aspects of fungous diseases. Springfield, 111.: Charles C Thomas. . 1963. Cutaneous (chancriform) syndrome in deep mycoses. Arch. Dermatol., 87:81.

2

Comparative immunologic aspects

A T FIRST GLANCE the systemic fungous infections appear to present the most extreme variability conceivable in their immunologic aspects. It is only necessary to compare the almost perfect immunologic response engendered in human beings infected with histoplasmosis (resulting in a death rate of perhaps 1 in 10,000 to 30,000) with the almost complete lack of immunologic resistance usually exhibited by those infected with cryptococcosis. Until recently it was customary to emphasize these differences so strongly as almost completely to ignore several very interesting similarities, whose importance now seems likely to transcend that of all the differences. In fact, it is becoming ever more probable that many of the "differences" alluded to do not in truth deserve the name, but are simply the result of gaps in our knowledge of the basic processes. One such gap has now been partly closed by the delineation of the chancriform syndrome discussed in chapter 1, which has demonstrated to us that we were previously trying to compare these diseases in what appeared to be the same stage of development, when in fact they were in entirely different stages.

13

14

The systemic mycoses

In his excellent monograph The Pathogenesis of Tuberculosis, Arnold Rich pointed out that "Nature, in the pursuance of her ends, is frequently profligate with materials, but she is always singularly conservative with methods." T h e totality of life existing on this planet depends ultimately on one single biochemical reaction, the ability of chlorophyll-containing plants to form nutritive carbohydrates from carbon dioxide and water under the stimulus of sunlight. With but little fundamental variation, hemoglobin carries oxygen in the blood of a fantastically large number of otherwise different forms of animal life. As Nature does not bother to invent numerous basic processes where one will serve adequately, it is extremely unlikely that she has furnished the human body with a different mechanism for resisting each infectious disease. Instead of emphasizing the differences in immunologic response, we should seek diligently for similarities, hoping eventually to find enough clues to reveal the basic pattern followed in all diseases. In this regard the systemic mycoses apparently have much to offer to the study of immunology, for a few potentially valuable clues are already known, and are constantly becoming better understood and are being more accurately interpreted. In the example of the extremes mentioned above, the all but complete difference between the immunologic responses to histoplasmosis and cryptococcosis is almost entirely explainable without postulating any basic differences in immunologic mechanisms. It is probably correct to state that Histoplasma capsulatum can infect all normal human beings and cause disease, whereas Cryptococcus neoformans never causes actual disease except in abnormal persons. Of the tremendous number of persons infected by Histoplasma, only a tiny percentage die, and they die because they are abnormal enough to fail to develop acquired immunologic resistance of sufficient quality to result in spontaneous cure. As a result, the death rate of histoplasmosis is actually very close to that of cryptococcosis. T h e real difference between the two diseases lies in the fact that Cryptococcus causes infection only in individuals who are immunologically defective, whereas Histoplasma may cause disease in all persons and then kill only those who are immunologically defective. Among the systemic mycoses there are intermediates between the above extremes. Coccidioidomycosis is similar to histoplasmosis, but the death rate is higher (about 1 in 3,000), indicating that the degree of immunologic response is quantitatively lower in a significant percentage of persons. Sporotrichosis calls forth a high degree of immunologic resistance, but still not so high as does histoplasmosis, for it often results in a chronic disease unless treated, though the death rate is very low. North American blastomycosis is considerably lower on the scale of immunologic resistance, and probably still lower is South American blastomycosis. Mucormycosis and aspergillosis are closely comparable to cryptococcosis.

Comparative immunologic aspects

15

Keeping the above thesis in mind, it is interesting to search for similarities in what little we know of the basic mechanism of immunologic responses to these several diseases. Immunology makes use of a number of tools in studying these responses, such as intradermal and serologic tests of various types designed to reveal the presence of the factors that confer immunity in response to infection. In the majority of infections where the mechanism is understood, acquired resistance results from the formation of antibodies by the tissues as a result of contact with the organisms. These antibodies are highly specific globulins (proteins) which apparently are closely related chemically to the antigens that stimulated their production. T h e ability of these antibodies to attach themselves to the organisms and cause them to become mutually adherent, to interfere with their respiration or metabolism, or to cause them to be more easily attached to and engulfed by phagocytes is an integral part of the immunologic process. Apparently a single antibody can, under appropriate circumstances, cause several of or all the reactions known as complement fixation, precipitation, agglutination, lysis, and opsonization, but more frequently such antibodies seem to be separate and able to fluctuate independently. A question yet to be answered conclusively is whether or not the immunity so quickly acquired by most persons exposed to histoplasmosis or coccidioidomycosis is caused by the production of specific antibodies effective against the disease, although it is almost impossible to explain the specificity of the immunity thus conferred by any other theory. Because coccidioidomycosis has been studied in this regard much longer than histoplasmosis, and many of its immunologic reactions are easier to understand, it serves well as a basis for continued discussion here, upon which some comparisons can later be made. As early as 1915 researchers began to develop testing procedures for coccidioidomycosis, utilizing extracts of cultures of that fungus as an antigen by intradermal injection and in serologic procedures, but almost twenty years passed before the procedures were sufficiently well understood and interpreted to be useful for diagnosis and prognosis. Their reputation in this regard has now become well established, and they are considerably more constant and reliable than similar processes in other systemic mycoses. A good part of their superiority stems from the fact that it is comparatively easy to obtain an active antigen from Coccidioides in a remarkably pure form without any important variation in the test results caused by the method of its production. Using such an extract, called coccidioidin, at least two antibodies specific for coccidioidomycosis are easily demonstrated in the serum of infected patients. T h e complement-fixation reaction, using coccidioidin as the antigen (performed as in the quantitative form of the Kolmer modification of the Wassermann test), reveals an antibody in the serum of many patients

16

T h e systemic mycoses

with coccidioidomycosis, in titers as high as 1:4,096. T h i s antibody, however, cannot be given credit for helping the human body to resist the disease; it is often entirely absent in persons who are resisting the disease almost perfectly, while it is always present in more serious cases, and continues to rise in titer ever higher as the disease becomes worse, even up to the time of death. It has thus become accepted as a means by which the clinician can measure the severity and the extent of the infection, but not the degree of the patient's resistance. T h e precipitin reaction using coccidioidin as the antigen also reveals an antibody in the serum of persons with coccidioidomycosis. T h i s antibody is entirely different from that of the complement-fixation test, because either may be present without the other, and they cannot be correlated in any way with each other. T h e precipitin antibody cannot assist the patient in resisting the disease, for it is present only in the first few months of the infection and then disappears, regardless of whether the patient recovers completely or dies. It is at once evident that death from coccidioidomycosis cannot be attributed to the inability of the human body to produce any specific antibody in response to the infection, for specific antibodies, especially of the complement-fixation type, are produced in large quantities. T h e antibody-production mechanism is therefore not paralyzed; it is working energetically, but its products are useless in the fight against the disease. Other methods of demonstrating these and perhaps other antibodies in serum are the immune adherence phenomenon, the fluorescent-antibody techniques, and the gel-diffusion procedures, which are presently being intensively studied. Nevertheless, by the methods thus far developed, no effective antibodies have been discovered in the circulating blood of persons w h o have demonstrated resistance to coccidioidomycosis. T h i s failure does not, however, deny the possibility that such antibodies exist. In fact, there are suggestive phenomena. For example, multiple transfusions of whole blood have often been employed with some apparent benefit in disseminated coccidioidomycosis. It is very likely that in many instances such blood was obtained from donors who had become immune to reinfection by recovering completely from the primary pulmonary form of the disease; in fact, in endemic areas up to 95 percent of the population have acquired specific immunity in this fashion. It is entirely possible that such blood may have helped the patient by furnishing specific antibodies that actually perform the desired function. T h e intracutaneous test using coccidioidin reveals an antibody in many persons infected with coccidioidomycosis which parallels rather closely the ability of the patient to resist the disease. Although there is no proof that this antibody is the one actually responsible for conferring immunologic resistance, it is heavily relied upon by clinicians in assessing the prognosis in various stages of the disease. T h i s antibody is usually said

Comparative immunologic aspects

17

to be fixed to the cells and not to be present in the circulating blood (at least not in the serum, although it may be present in circulating cells). The above-mentioned three forms of antibodies have been similarly demonstrated in several other systemic mycoses, and in many aspects the reactions follow the same pattern as in coccidioidomycosis. It is, however, more difficult to obtain uniform extracts from cultures of the other causative fungi, some of which require more enriched media than Coccidioides for growth; these media may add materials to the extracts which are capable of causing false positive reactions. Also, several of these fungi are biphasic in culture, and each phase may yield a different antigen. So many investigators have used different methods of producing their antigens that it is not difficult to understand why there is still wide variation in their results. Because the tests are very useful in coccidioidomycosis, it would be worthwhile to try to develop antigens specifically selected for their ability to perform the same service in other systemic mycoses. Nevertheless, despite all these discrepancies, the ability to react to the intracutaneous test with antigens specific for each disease does seem to parallel rather closely the immunologic resistance to sporotrichosis, histoplasmosis, North American blastomycosis, chromoblastomycosis, and some forms of maduromycosis, as it does in coccidioidomycosis. The same reaction probably occurs also in South American blastomycosis. In persons infected with cryptococcosis, phycomycosis, and aspergillosis, skin tests have not produced positive reactions, a result usually attributed to the fact that these fungi are poorly antigenic. It is much more plausible to place the blame on the patient's immunologic system, which must have been defective if the fungi were permitted to cause disease at all. In all the other systemic mycoses the skin test is equally negative when the patient is resisting the disease as poorly as are those with cryptococcosis, phycomycosis, and aspergillosis. It might be positive if tested on patients who have recovered from these diseases by immunologic means alone. The complement-fixation test, which is useful in histoplasmosis, North American blastomycosis, and South American blastomycosis, follows rather closely the pattern of the same test in coccidioidomycosis, the titer rising in proportion to the severity of the disease. It has also been observed to work in a similar fashion in a few cases of maduromycosis caused by Nocardia brasiliensis. No success has attended complement-fixation testing in cryptococcosis, where it might be expected to be high in titer. A possible explanation is that cultures of this organism consist of perhaps twenty to thirty times as much capsular material as that derived from the fungus cells themselves. The capsules are pure polysaccharide, and it may be necessary to use a more protein-like material, such as might be obtainable from the cell walls. This finding is in keeping with complement-fixation tests in other deep mycoses, in which removal of all nitrogenous material from the antigens to produce pure polysaccharides

18

The systemic mycoses

diminishes or destroys the ability to p r o d u c e complement-fixation titers. S a l v i n has recently r e p o r t e d progress i n this d i r e c t i o n (see c h a p . 9). P r e c i p i t i n testing is considered u s e f u l in histoplasmosis, b u t does n o t c o n f o r m closely to the p a t t e r n i n coccidioidomycosis. I t is e v e n less w e l l d e v e l o p e d i n the other systemic mycoses.

Bibliography Ball, O. G., F. L. Lummus, M. L. Sigrest, J. F. Busey, and F. Allison, Jr. i960. A n immunologic survey for systemic fungous infections in general hospital patients of central Mississippi. Amer. J. Hyg., 72:231. Campbell, C. C., and G. E. Brinkley. 1953. Serologic diagnosis of histoplasmosis, coccidioidomycosis and blastomycosis and the probability of cross reactions. J. Lab. Clin. Med., 42:896. Frenkel, J. K. 1962. Role of corticosteroids as predisposing factors in fungal diseases. Lab. Invest., 11:1192. Levine, H. B., J. M. Cobb, and C. E. Smith, i960. Immunity to coccodioidomycosis induced in mice by purified spherules, arthrospores and mycelial vaccines, Trans. N. Y. Acad. Sci., 2d ser., 22:436. Louria, D. B., N. Fallon, and H. G. Browne, i960. T h e influence of cortisone on experimental fungous infections in mice. J. Clin. Invest., 39:1435. Magnusson, M. 1962. Sensitin for antigens such as coccidioidin, tuberculin, etc. Amer. Rev. Respir. Diseases, 86:395. Martin, D. S. 1957. Evaluation of skin tests and serologic methods in fungous infections. J. Chron. Diseases, 5:580. Pappagianis, D. 1961. Active immunity in coccodioidomycosis: natural and laboratory features. Stanford Med. Bull., 19 (Feb.): 35. Smith, C. E. 1956. Pattern of 39,500 serologic tests in coccidioidomycosis. J. Amer. Med. Assoc., 160:546. Smith, C. E., M. T . Saito, R. R. Beard, R. Mc. Kepp, R . W . Clark, and B. V. Eddie. 1950. Serologic tests in the diagnosis and prognosis of coccidioidomycosis. Amer. J. Hyg., 52:1. Smith, C. E., E. G. Whiting, E. E. Baker, H. G. Rosenberger, R. R . Beard, and M. T . Saito. 1948. T h e use of coccidioidin. Amer. Rev. Tuberc. Pulmon. Diseases, 57:339. Wilson, J. W. 1957. Clinical and immunologic aspects of fungous diseases. Springfield, 111.: Charles C Thomas. . 1963. Cutaneous (chancriform) syndrome in deep mycoses. Arch. Dermatol., 87:81. Wilson, J. W., C. E. Smith, and O. A. Plunkett. 1953. Primary cutaneous coccidioidomycosis: the criteria for diagnosis. Calif. Med., 79:233.

3 Therapeutic aspects

IN E A C H succeeding chapter devoted to a specific systemic fungous infection, there is a detailed discussion of the treatment appropriate for that disease. In the present chapter some preliminary generalizations, more or less applicable to the entire group, are presented. Several systemic mycoses exist in a form so mild (and so well resisted) in many of the infected persons as to promise complete spontaneous recovery because of natural or acquired specific immunologic resistance factors. In these cases it is often possible to make a benign prognosis with sufficient accuracy to avoid heroic drug or surgical therapy, which might add unnecessary hazards. T h e delineation of the primary cutaneous inoculation form of several of these diseases as chancriform, and as likely to clear without the addition of strenuous or potentially dangerous therapy, is significant. Even more important is the realization that cutaneous lesions not of the chancriform type are probably caused by hematogenous dissemination, and are therefore sufficiently dangerous to life to deserve more stringent measures. In some of these diseases intracutaneous and

19

20

The systemic mycoses

serologic tests enhance the certainty of prognostic conclusions, and should therefore be routinely employed before selection of the therapeutic regimen. In all the deep mycoses it is important to assist the development of specific immunologic resistance. Bed rest, ample nutrition emphasizing protein, and supplemental vitamins (especially of the B group and C) should be provided for even the mildest of proved cases, and should be continued until all physical signs and laboratory procedures, including specific skin and serologic tests, indicate a good prognosis. Anemia must be controlled by transfusions of whole blood, if necessary. It has even been speculated that blood, if obtained from an immune donor, may furnish antibodies specific for the disease. Antibiotics of the antibacterial type should be withheld unless indicated specifically for proved superimposed infection. Corticosteroids may interfere with the development of specific immunologic resistance, and should not be used except perhaps minimally to ameliorate highly uncomfortable allergic manifestations, such as mycids or drug reactions. A l l the deep fungous infections may endanger life, although the percentages vary greatly. It is ever more evident that the severe forms occur predominantly in persons who possess some fundamental defect in their immunologic defense mechanisms. Sometimes these deficiencies appear to be due or related to a concomitant debilitating illness, such as leukemia, Hodgkin's disease or other lymphoblastoma, sarcoidosis, diabetes, tuberculosis, or some other concomitant deep mycosis. T h e y sometimes emerge only during treatment with corticosteroids, nitrogen mustards, or other antimitotic drugs, or antibacterial antibiotics. Attention must be given to all such possible factors as a fundamental part of the therapy of a mycosis. Occasionally treatment methods or drugs discovered long ago have continued to prove so successful for a particular disease as to approach the ideal. T h e most impressive of these is iodide therapy for sporotrichosis, which is so reliable that it is unlikely ever to be supplanted by a competing drug. Although not so nearly perfect, penicillin still enjoys good confidence for actinomycosis, and sulfonamides are excellent for some forms of nocardiosis. But for the other systemic mycoses the ideal treatment has yet to be found, despite the fact that literally hundreds of drugs have been tried. AMPHOTERICIN

B

It is most encouraging to be able to report that for several of these infections amphotericin B has continued to increase in effectiveness since its discovery in 1955. It has almost entirely eliminated other competitive drugs, even though its toxicity has created difficulties. Amphotericin B and its general mode of administration are discussed here in order to avoid

Therapeutic aspects

21

repetition later, when the diseases in whose treatment it is useful are taken up individually. Amphotericin B is an antifungal antibiotic, probably a conjugated heptene, produced by a strain of Streptomyces nodosus originally found by Gold, Stout, Pagano, and Donovick (1956) in a soil specimen from Venezuela, and studied chemically and biologically by several other groups. It is a yellowish powder, insoluble in most organic solvents and only slightly soluble in water, even at extremes of pH. Colloidal dispersion through the use of sodium desoxycholate has rendered it biologically usable to a reasonable, although not ideal, degree. It is poorly absorbed from the gastrointestinal tract, yielding probably not more than 0.3 mg per milliliter in serum and much less in the central nervous system. Subcutaneous or intramuscular injection is usually inefficient and troublesome. Reasonable levels of amphotericin B can be maintained in serum for somewhat more than twenty-four hours by intravenous administration. T h e sterile lyophilized powder (available in vials containing 50 mg together with the dispersing and buffering agents*) is dispersed in 5 percent dextrose solution (not saline, which causes precipitation) in concentrations of from 0.1 to 0.5 mg per milliliter (preferably the former to minimize thrombophlebitis). T h e maximum tolerated dose is from 1.0 to 1.6 mg per kilogram of body weight. In practice, except for exceptionally large or exceptionally small persons, it is customary to administer one 50-mg vial as the total dose at one time, usually on alternate rather than on consecutive days, for twenty to sixty days (or more if needed and tolerated). Usually one-quarter of this dosage is given daily at first. T o minimize toxicity, at least six hours should be taken to administer the dose by slow drip. When especially indicated, the intravenous dosage may be supplemented (or sometimes replaced) by administration of the drug intrathecally (1 mg); topically, as in the eye (1-5 mg); intra-articularly (up to 25 mg); intrathoracically (up to 3 mg); into cutaneous lesions (up to 25 mg with 2 percent procaine) every other day; or as an aerosol inhalant spray (5 mg every six hours). Amphotericin B is undesirably but not impractically toxic. Fever and chills, nausea, vomiting, headache, anorexia, malaise, and elevation of the blood nitrogen and creatinine, at times with urinary casts, blood, and albumin, are the usual toxic effects; more rarely, anemia, thrombocytopenia, gastrointestinal complaints, polymyositis, or hypokalemia may result from use of the drug. T h e renal effects are the most important objectionable feature, at times necessitating temporary reduction of dosage or cessation of treatment. These effects, however, usually are only temporary, the patient returning to normal within a week after withdrawal of the drug; it has become customary to continue the dosage even in the face • E. R. Squibb & Sons.

22

The systemic mycoses

of azotemia of a degree formerly considered too dangerous, provided that the seriousness of the fungal infection continues to warrant such continuance. Holeman and Einstein report that potassium depletion is more consistently present and more important than heretofore documented, and that it may even bear a causative relationship to tubular kidney damage capable of resulting in permanent impairment. T h e other side effects, such as fever, chills, nausea, anorexia, and abdominal pain, can be at least partly controlled by giving oral acetylsalicylic acid, antihistaminics, and 50 mg of chlorpromazine before administering the dose of amphotericin B. Twenty to 100 mg of soluble hydrocortisone dissolved in each intravenous infusion seems to be helpful, although it may be unwise to use this drug in the treatment of granulomatous diseases, for it may inhibit the immune mechanisms of quasi-allergic nature which seem so important. Other suggestions to minimize side reactions include maintaining the patient in the recumbent position throughout the administration of the drug, the use of warm bedclothing, the forcing of fluids, and agitation of the infusion bottle at frequent intervals to keep the drug evenly suspended. T h e addition of 25 mg of aqueous heparin to each infusion has been recommended to reduce thrombophlebitis. Allergic hypersensitivity to amphotericin B, though rarely observed, may make further administration impossible. In vitro the antifungal spectrum of amphotericin B covers a wide variety of fungi that cause systemic infections, including Cryptococcus neoformans, Blastomyces dermatitidis, Blastomyces (Paracoccidioides) brasiliensis, Candida albicans, Histoplasma capsulatum, Sporotrichum schenckii, and most strains of Coccidioides immitis. (Some examples of acquired resistance to amphotericin B by some strains of pathogenic fungi, especially Coccidioides and Candida, have been reported.) A n ever-expanding clinical experience in the treatment of human infections caused by these various fungi thus far confirms these findings in vivo. Although not truly ideal or invariably reliable, amphotericin B is far more useful than any drug previously tested for most of these disorders. A t the time of this writing the only other drug being seriously considered as a competitor of amphotericin B is a compound not generally available. Designated by the number X-5079C, it is under study by Hoffman LaRoche. As a water-soluble antibiotic, it is capable of being administered subcutaneously or intramuscularly (in contrast with amphotericin B). Apparently it is particularly effective in treating histoplasmosis, North American blastomycosis, and systemic sporotrichosis. It is not active against cryptococcosis, and is less efficient against coccidioidomycosis than amphotericin B. It causes a rapid rise in brom-sulfone-phthalein retention when treatment is started, but there is a return to normal when the drug is stopped, apparently without causing permanent liver damage. It is most important, however, to realize that neither amphotericin B nor probably any other drug can kill every fungal organism in a diseased

Therapeutic aspects

23

body. At best it can only reduce the number of organisms or prevent their propagation to a point where the mechanisms of immunologic resistance, both natural and acquired, are potent enough to take over and bring complete and permanent recovery. In some of the deep mycoses, most impressively coccidioidomycosis and histoplasmosis, the early spontaneous development of a completely and probably permanently effective specific resistance is almost the rule; those persons who do not so succeed are deficient in such mechanisms to a very important degree. Some of these deficiencies may correct themselves or may be correctable by medical means; others may be permanent. If they are permanent, it is logical to expect the recurrence of the disease when antifungal drug therapy has been stopped, because the immunologic defect that originally allowed it to become severe is still dominant, leaving the patient as unprotected as before. This situation is especially worrisome when dealing with drugs known to be not fungicidal but only fungistatic, such as amphotericin B. Sufficient time has not yet elapsed to be sure that some of the cures being attributed to amphotericin B are not simply temporary remissions, and optimism should remain guarded for several years. The study of immunology should be extended as much as possible, as a victory in this field would be truly the ideal. It is particularly depressing to observe that no large number of antibiotics is looming on the horizon from which alternatives might be selected when the causative fungi have learned to develop strains resistant to amphotericin B. Such development must, after all, be considered almost inevitable. There is, however, an important source of comfort here, in contrast with the discouraging aspect with regard to acquired resistance to griseofulvin in dermatophytosis or the much more thoroughly established emergence of strains of bacteria which have become resistant to the antibacterial antibiotics. In diseases caused by bacteria the resistant strains may be (and frequently are) passed on from the patients to cause resistant infections in other persons, thereby perpetuating the process of diminishing the reliability of the drugs. As direct transmission from human to human rarely, if ever, occurs in the deep mycoses, the development of resistance to amphotericin B by the causative fungus in one patient would be important only to that patient, for the resistant fungus would not be transferred to another human being. The great mass reservoir of fungi in nature from which other human infections will come will never be exposed to amphotericin B, and will therefore have no opportunity to develop strains resistant to it.

Bibliography Banner, E., H. Zinnes, R. A. Moe, and J . S. Kulesza. 1958. Studies on a new solubilized preparation of amphotericin B. Antibiot. Ann., 1957-58: 53-58. Beard, H. W., J . H. Richert, and R. R. Taylor, i960. The treatment of deep mycotic infections with amphotericin B. Amer. Rev. Respir. Diseases, 81:43.

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Campbell, C . C., and G . B. Hill. i960. Beneficial therapeutic effects of solubilized amphotericin B after oral administration in experimental coccidioidomycosis, histoplasmosis and cryptococcosis in mice. Antibiot. A n n . , 195960:622. Dutcher, J. D., M . B. Y o u n g , J. H . Sherman, W . Hibbits, and D. R . Walters. 1957. Chemical studies on amphotericin B. Antibiot. A n n . , 1956-57: 866-869. Emmons, C . W . 1961. Chemotherapeutic and toxic activity of the antifungal agent X - 5 0 7 9 C in experimental mycoses. A m e r . R e v . Respir. Diseases, 84:507. Emmons, C. W . , a n d W . R . Piggott. 1959. Amphotericin B and griseofulvin in the treatment of experimental systemic mycoses. Antibiotics and Chemotherapy, 9:550. Fonkalsrud, E. W . , J. Shiner, R . H a a n , S. A . Marables, V . D . Newcomer, and D. B. R o c h l i n . 1961. Experimental studies and clinical experience with isolated limb perfusion of fungicidal drugs. Surg. Gynecol. Obstetr., 113:306. Gold, W . , H . A . Stout, J. F. Pagano, and R . Donovick. 1956. Amphotericins A and B : antifungal antibiotics produced by a streptomycete. I. I n vitro studies. Antibiot. A n n . , 1955-56: 579-586. Grunberg, E., J. Berger, and E. Titsworth. 1961. Chemotherapeutic studies o n a new antifungal agent, X-5079C, effective against systemic mycoses. [Abstract.] Amer. R e v . Respir. Diseases, 84:504. Halde, C., V . D. Newcomer, E. T . W r i g h t , and T . H . Sternberg. 1957. A n evaluation of amphotericin B in vitro and in vivo in mice against Coccidioides immitis and Candida albicans, a n d preliminary observations concerning the administration of amphotericin B to man. J. Invest. Dermatol., 28:217-232. Latapi, F. i960. Griseofulvin in the treatment of some deep mycoses. Arch. Dermatol., 81:841. Louria, D. B. 1958. Some aspects of the absorption, distribution and excretion of amphotericin B in man. Antibiot. M e d . Clin. T h e r . , 5:295. M c N a l l , E. G „ C. Halde, V . D. Newcomer, and T . H . Sternberg. 1958. A biological assay for the determination of amphotericin A and B in biological fluids. Antibiot. A n n . , 1957-58:131-136. Newcomer, V . D., T . H . Sternberg, E. T . W r i g h t , and R . M . Reisner. 1959. Current status of amphotericin B in treatment of systemic fungous infections. J. C h r o n . Diseases, 9:353-374. Newcomer, V . D., T . H . Sternberg, E. T . W r i g h t , R . M . Reisner, E. G. McNall, and L . J. Sorensen. i960. T h e treatment of systemic fungous infections with amphotericin B. A n n . N . Y . Acad. Sci., 89:221. Procknow, J. J. i960. T h e r a p y of the systematic mycoses. J. Florida Med. Assoc.,

47=393Seabury, J. H., and H . E. Dascomb. 1958. Experience with amphotericin B for the treatment of systemic mycoses. Arch. Intern. Med., 102:906-976. . i960. Experiences with amphotericin B. A n n . N . Y . Acad. Sci., 89:202. Smith, D. E., and J. H . Matthews, i960. T r e a t m e n t of pulmonary mycotic infections with amphotericin B. N e w Engl. J. Med., 263:782. Steinberg, B. A., W . P. Jambor, and L . O . Suydam. 1956. Amphotericins A and B: two new antifungal antibiotics possessing h i g h activity against deep-seated and superficial mycoses. Antibiot. A n n . , 1955-56:574-578.

4 Coccidioidomycosis

INTRODUCTION COCCIDIOIDOMYCOSIS exhibits a wide range of clinical manifestations, almost as varied as those of tuberculosis, which it resembles in many respects. More often than not it runs its course without becoming apparent unless specifically tested for; it may be relatively benign, severe, or fatal, according to the immunologic resistance engendered by the host in response to its invasion. It has been selected for discussion at this point, even though we may seem to be giving it more prominence than it deserves, because its immunologic processes follow a much simpler and more easily understood pattern than do those of other microbial diseases. We hope to establish a foundation of understanding which will be of help later in discussions of more difficult problems. Coccidioidomycosis is more worthy of study than might appear at first glance, because a person who has become infected has ample time to travel to any part of the globe before symptoms appear. Correct identification of the disease is not diffi-

25

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The systemic mycoses

cult, and will greatly benefit the patient and bring credit to the diagnostician. ETIOLOGY Coccidioidomycosis is caused by a single species of fungus, Coccidioides immitis. There is considerable variation among strains in culture on artificial media; some are more productive of antigens; and some are more pathogenic to laboratory animals. None of these differences, however, have been correlatable with the clinical course of the disease in human beings. Stiles named the organism Coccidioides because in histopathologic sections it resembled Coccidia, a group of Protozoa, usually species of Eimeria or Isospora, which are pathogenic for animals and fowls, and occasionally for man. T h e species name assigned to the organism was immitis (Latin for "not mild," but, in the manner of Latin negatives, really meaning the very antithesis of mild, and therefore "fierce"). HISTORY In 1892, from Argentina, Posadas reported in a wealth of detail the first case of coccidioidomycosis. In collaboration with Wernicke, he delineated the new entity during the next few years, without, however, realizing that it was not caused by a protozoan. Rixford discovered a case in California in 1894, and, with the help of Gilchrist, published an admirably extensive study in 1896. T h e fungous nature of the organism was established by Ophuls and Moffit in 1900. A few new cases were reported each year, almost exclusively from California, and the name "coccidioidal granuloma" became popularized. In 1928 Jacobson began to study skin and serologic tests, using extracts of Coccidioides as antigens, but abandoned the procedure because of faulty interpretation of the results. Subsequently Kessel, and especially C. E. Smith, developed these techniques until they could serve for both diagnosis and prognosis. By 1935 coccidioidomycosis had been well established in what appeared to be its proper niche among the very rare chronic, wasting diseases. T h e n Gifford and Dickson made a revolutionary discovery, linking the disease with a frequently encountered, comparatively mild inflammatory respiratory infection known as "valley fever" because of its being limited largely to the San Joaquin Valley in south central California. In 1947 Wilson, Smith, and Plunkett began the study of a patient known to have been inoculated directly through the skin, and in 1953 reported the chancriform primary cutaneous syndrome subsequently well established for this disease. Although still very rare, this process has helped us better to understand a similar clinical picture in other infectious diseases.

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DISTRIBUTION T h e fungus Coccidioides immitis exists in nature, actively growing in the soil of certain geographic areas and producing light arthrospores which, borne on the winds, are scattered for considerable distances. The principal regions where climatic conditions afford the necessary factors are south central California and parts of Los Angeles County, Arizona, New Mexico, Texas, and the northern states of Mexico. There is another endemic focus in the Gran Chaco region of South America, from which the first known case arose. Occasional instances have recently been reported in Venezuela and Central America, and it has been suggested that a similar disease exists in Russia. No age group is exempt from the disease, but the more serious forms occur in males during the third and fourth decades. T h e more deeply pigmented races, and individuals whose occupations expose them to the inhalation of terrestrial dust, are especially susceptible. EPIDEMIOLOGY That the soil is the natural habitat of C. immitis has been repeatedly demonstrated by culturing it from terrestrial dust of many regions where it is endemic. There is, however, no adequate explanation as to why the disease remains so closely confined to certain areas. The fungus grows very well in any soil from which all microbial competitors have been excluded by sterilization, and in a large percentage of soils not so prepared, making it difficult to understand why it does not spread widely over the globe. As certain rodents are known to harbor the infection, Emmons (1942) has suggested that they may serve as endemic hosts, but they cannot be held responsible for establishing boundaries because they are neither present in all endemic areas nor limited to them. Maddy has pointed out how closely these areas adhere to the region geologically classed as the Lower Sonoran life zone. A season of adequate rainfall is necessary to allow time for the fungus to grow, followed by a long hot, dry, dustproducing period with recurring winds to disperse the spore-bearing product. From such soil sources the fungus enters the lungs and causes primary pulmonary infection. As expected, the incidence increases sharply in the late, dry summer months. Measures effective in controlling dust, such as installing lawns or pavement, or wetting down places where persons must work, have been shown markedly to reduce the incidence of coccidioidomycosis. Masks may be worn in especially dangerous circumstances. The fungus may enter the body by way of the respiratory or gastrointestinal tracts or by being inoculated directly through the skin. However,

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healthy animals do not become infected with the disease by ingesting the organisms, as in tuberculosis. The customary statement that "transmission from man to man, or from animals to man, has not occurred" is probably still true in the strictest sense, but a mortuary attendant inoculated his finger from a cadaver, and, in one instance, several nursing attendants acquired the pulmonary infection by inhaling spores blown from the interior of a plaster cast while it was being removed from a limb involved in coccidioidal infection. Here the fungus was growing on the exudate in the same saprophytic stage as it does on artificial culture media and in the soil. CLINICAL

CHARACTERISTICS

Primary pulmonary coccidioidomycosis Coccidioidomycosis, far from being the rare disease it was originally considered, is now known to be acquired, in its primary pulmonary form, by almost all previously uninfected persons who inhale C. immitis in any significant quantity. The incubation period is from ten days to four weeks. More than half of the infected persons, however, show no symptoms whatever, and remain entirely unaware of the disease throughout its course; nevertheless, they are then apparently immune to reinfection. (These facts are revealed only because during the process these individuals acquire the ability to react to the skin test with coccidioidin, to be discussed in detail later in connection with immunity.) Even the cases that are accompanied by symptoms are frequently very mild, the illness being classed by both patient and physician simply as a cold or as influenza. In other people, however, the disorder may be very severe, accompanied by pulmonary symptoms and signs of almost any type and degree, most of which, however, are not specific for this disease. Fever, malaise, chills, cough, noctidrosis, nasopharyngitis, chest pain, headache, and backache are common manifestations. There is a wide variety of pathologic pulmonary changes, including various combinations of pleurisy, effusion, hilar thickening, parenchymal nodules, bronchopneumonia or lobar consolidation, cavity formation, and miliary scattering. Physical examination usually reveals less than the changes that are actually present would indicate. Rales, dullness, suppression of breath sounds, and pleuritic friction rubs may be demonstrable. X-ray examination is frequently negative, even in well-developed cases, but in others may reveal a wide variety of abnormalities, most of which cannot be differentiated from those caused by other pulmonary diseases. A fuzzy peribronchial infiltration in the hilar region is the rule in mild cases, whereas in a more severe illness a soft, homogenous bronchopneumonic infiltration is characteristic, more likely to favor the middle and lower lobes, in contrast with tuberculosis. In these areas there are often

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isolated, well-circumscribed nodules, suggestive of metastatic malignancy. Cavities occur frequently, more often than not characterized by being exceptionally thin-walled and free of surrounding parenchymal infiltration, so as to suggest cysts; they are frequently not revealed by ordinary flat radiographs, but only by planographs. Pleural effusion occurs in about 20 percent of all cases, but tends to be minimal and evanescent. From one to two weeks after the onset of symptoms, allergic eruptions appear in percentages of cases varying from 30 percent in white women to 2 percent in deeply pigmented men. Any form of erythema multiforme may be seen, but the commonest and most typical is erythema nodosum, consisting of one or several large tender, erythematous nodular swellings usually situated below the knees. These manifestations are caused, not by the spread of the infection itself, but by the hematogenous scattering of toxic products derived from the pulmonary focus, acting in conjunction with the specific cutaneous hypersensitization which has developed, shown by the ability to react to the skin test with coccidioidin. There are, therefore, coccidioidids, analagous to trichophytids, tuberculids, and the like. Acute arthritis occurs occasionally by the same mechanism. Any of these allergic reactions is usually accompanied by a significant degree of eosinophilia. This reactivity is extremely valuable in prognosis, because patients who exhibit any of these phenomena are virtually certain to recover from the disease rapidly and completely. (The significance of this important fact is discussed later.) Primary pulmonary coccidioidomycosis results in complete recovery in all but a very small percentage of cases, approximately one per thousand. Usually there are no sequelae except persistence of the ability to react to the skin test with coccidioidin and an apparently complete immunity to reinfection which endures for many years, probably for life. Recovery may be delayed for some months, however, in about 5 percent of the cases by extensive pneumonic infiltrations, persistent parenchymatous nodules consisting of rounded solid foci called coccidioidomas; thick-walled abscesses; thin-walled, cystlike cavities; or end-point lesions with calcification, fibrosis, or bronchiectasis. Such patients must be guarded, lest they resume physical activity prematurely and thereby lose the chance of complete recovery. They should also be watched carefully for evidence of dissemination, although neither of these events occurs frequently, in contrast with tuberculosis. Local pulmonary changes must not be confused with dissemination itself. Primary cutaneous coccidioidomycosis As noted above, coccidioidomycosis was formerly believed to occur frequently by direct inoculation of the fungus into the skin, but recent events indicate that such infections are probably extremely rare. Often a lesion in the skin is indeed the first sign that the disease is present, but in almost

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The systemic mycoses

all recorded cases the subsequent course of events strongly suggests that the organisms were brought to that point by being disseminated from a primary pulmonary focus, previously unrecognized because it was too mild to attract attention. This view is no longer difficult to accept because more than half of the primary pulmonary cases remain entirely subclinical, and many others are never recognized specifically as coccidioidal infections. This subject might have remained obscure except for a most instructive case observed in 1948 by Wilson, Smith, and Plunkett, when an embalmer acquired an infection in an abrasion on his finger while preparing the body of a person dead of disseminated coccidioidomycosis. An indurated, relatively painless ulcerated lesion appeared at the inoculated site, closely resembling the primary chancre of syphilis or of sporotrichosis. There was mild fever. In a short time eight nodules appeared along the lymphatic channels draining this area, accompanied by lymphangitis and followed by epitrochlear and axillary lymphadenopathy. The picture was identical with that of the most common type of sporotrichosis. Without the benefit of any treatment that could have been considered specifically effective, the entire syndrome subsided, and the patient has remained well. These authors (Wilson, Smith, and Plunkett, 1953) enumerated the following criteria they believe should be fulfilled if a case is to be accepted as belonging to this type. There should be no history of significant pulmonary disease immediately preceding the appearance of the first observed cutaneous lesion, but the lesion should suggest that there was a chance of inoculation through an actual break in the skin at that site; a simple injury, such as a bump or a bruise, is insufficient evidence. Only a short incubation period should elapse, probably between one and four weeks, before a visible cutaneous lesion develops. The primary lesion should be a relatively painless, firmly indurated nodule or nodular plaque with central ulceration, resembling a chancre as seen in primary syphilis or the primary cutaneous tuberculous complex, rather than an abscess or torpid cutaneous ulcer. Lymphangitis and lymphadenopathy should develop, but only in the region of lymphatic drainage. Development of nodules similar to those seen in sporotrichosis may be expected. Spontaneous healing of the primary cutaneous syndrome should occur within a few weeks, unless the patient is immunologically defective; such deficiency should be anticipated in only one or two per thousand instances. Skin and serologic tests with coccidioidin (to be described in detail later) furnish additional clues, as their time sequence and the interplay of titers are distinctly different in the primary stage from their manifestation in the disseminated form. A similar case, acquired in a laboratory, was reported by Trimble and Doucette in 1956, and another one was noted by Wright and Newcomer in i960. Winn has seen similar cases, and Maddy has observed the same clinical picture in dogs. Goodman and Schabarum (1963) have recently

Coccidioidomycosis: nondisseminated type. Upper left: primary cutaneous (chancriform) type, caused by direct percutaneous inoculation of Coccidioides immitis (rare). Lower left and upper right: erythema multiforme accompanying early coccidioidomycosis; an allergic reaction (coccidioidid) to bloodborne specific toxic fungal material. Middle right: erythema nodosum of similar origin. Lower right: strongly positive 48-hour reaction to intradermally injected coccidioidin. PLATE I.

P L A T E 2. Coccidioidomycosis: disseminated type. Upper left: inguinal granuloma in child. Middle and lower left: papular lesions on forehead and wrist. Upper right: fluctuant subcutaneous abcesses in left malar and sternoclavicular areas. Lower right: fungating granulomas in right malar and sternal regions and on right arm.

3. Coccidioidomycosis: disseminated type. Upper left: multiple tiny cutaneous foci during miliary dissemination. Middle left: extensive granulomatous involvement of hand. Lower left: orbital abscess accompanying involvement of central nervous system. Upper right: scarring after spontaneous healing of granulomatous area on forehead, with active area still visible on cheek. Lower right: extensive granulomatous destruction shortly before death. PLATE

4. Coccidioidomycosis: histopathology and appearance in culture. Upper left: histopathologic appearance of cutaneous lesion in disseminated type (H & E x 100). Middle left: very unusual picture, showing entire life cycle of Coccidioides immitis in one microscopic field, from edge of a lung abscess cavity aerated from a bronchus (H & E X400). Lower left: immature spherules of C. immitis (PAS x 200). Upper right: rupturing spherule (Gridley stain x 600). Middle right: asteroid form resembling actinomycotic granule (H & E x 1,000). Lower right: gross appearance of C. immitis colony on Sabouraud's agar. PLATE

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reported a case of this type acquired from natural sources, which fulfilled all the criteria perfectly. These cases have been entirely different from all others only presumed to have been primarily inoculated into the skin; the latter were characterized by lesions in keeping with those commonly observed in disseminated disease. In fact, most of them progressed to the disseminated form, which they almost certainly were when first observed. It may seem unnecessary to discuss a rarity like this in so much detail, but it is highly important that no case be mildly treated because it is wrongly diagnosed as being of primary cutaneous origin, when it actually is of the much more serious disseminated type needing strenuous therapy. T h e danger lies in the fact that, except for these extremely rare instances, all cutaneous lesions mean that dissemination has already occurred. Almost all persons who acquire coccidioidomycosis by the primary pulmonary route recover quickly and are thereafter immune to reinfection. Only one or two per thousand, immunologically defective, subsequently have the disease in the disseminated, granulomatous form which often causes death. It would be most unlikely that the disease caused by primary cutaneous inoculation of the organisms would pursue a different course; indeed, as the skin is highly reactive to the products of the fungus (coccidioidin) in those persons who do acquire immunologic resistance, inoculation by the intracutaneous route theoretically should confer immunity even more quickly and consistently than does pulmonary infection. Therefore, because rapid involution of the primary cutaneous chancre and its sequelae should be expected in all but one or two per thousand cases, the continuation of a cutaneous lesion for more than three months should be

Fig. 1. Coccidioidomycosis: dissemination in lungs. Left: con fluent infiltration throughout right upper lobe with cavitation and marked mediastinal lymphadenopathy. Right: extensive dissemination throughout both lungs, nine days later.

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T h e systemic mycoses

considered strong evidence against its having arisen by primary cutaneous inoculation. Disseminated coccidioidomycosis (coccidioidal granuloma) Dissemination may occur early in the course of the disease and proceed rapidly to massive involvement by widely distributed tiny foci simulating miliary tuberculosis, and leading to early death. At the other extreme, a person previously unaware of any illness may develop a solitary disseminated lesion which then progresses slowly or even intermittently. Many such lesions may heal, and some of these patients eventually recover completely. In other cases, still more foci develop, enlarge, and ultimately cause death, sometimes after only a few months, sometimes not for years. Although it has been postulated that inhalation of massive amounts of spores causes more serious degrees of infection, the principal factor determining whether or not dissemination will occur seems to be the possession by certain persons of an immunity mechanism that is inherently defective in some vital feature. Males are more susceptible than females, and the incidence increases with depth of skin pigmentation, although Filipinos apparently resist the disease less well than darker-skinned Negroes. Dissemination is usually hemotogenous, more rarely lymphatic. Dissemination most commonly involves lungs, skin and subcutaneous

Fig. 2. Coccidioidomycosis: lesion in metatarsal bone. Left: osteolytic lesion in base of fifth metatarsal, with slight periosteal reaction. Middle: further destruction and periosteal bone formation. Right: coccidioidal osteomyelitis has undergone complete healing.

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tissues, bones, joints, viscera, meninges, and brain. In striking contrast with tuberculosis, the gastrointestinal tract is remarkably resistant to coccidioidal involvement, both when the organisms are disseminated to it by the bloodstream and when they are ingested. Dissemination is to be suspected in the lungs themselves, rather than simple increase in severity of the primary pulmonary infection, when the mediastinal adenopathy is marked and progressive, and when lesions resembling the adult type of tuberculosis develop, particularly in the apices. Disseminated lesions in bone are likely to select points of tension or pressure, such as the insertion of tendons or ligaments; they have a peculiar "punched-out" appearance, resembling cysts, with a sharp line of transition from destroyed bone to bone that is still healthy. If bony lesions extend to joint cavities, the weight-bearing surfaces are characteristically spared at first, in contrast with tuberculosis.

Fig. 3. Coccidioidomycosis: involvement of vertebral body. Left: destruction and collapse of body of L2; note preservation of intervertebral disks. Right: spine has been surgically fused; collapsed vertebra shows evidence of healing.

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The systemic mycoses

Dissemination into the skin produces one or more subcutaneous abscesses which slowly enlarge, and after spontaneous rupture or incision leave chronic torpid draining sinuses. At the periphery of such lesions the skin frequently becomes extensively secondarily infected, simulating scrofuloderma. Occasionally large areas may ultimately be involved in this manner in an ulcerative, granulomatous process exhibiting irregular serpiginous borders and central atrophic scars, bearing considerable resemblance to the usual form of chronic cutaneous North American blastomycosis. In the viscera, lesions usually do not appear in a single organ, but tend to be more widely disseminated. Involvement of the central nervous system, usually in the form of meningitis, is more common in light- than in dark-skinned persons. Without proper and vigorous treatment this form of the disease is almost always fatal, although sometimes it progresses slowly. Fever, chills, prostration, and progressive emaciation are typical symptoms in all types of disseminated coccidioidomycosis. Hypochromic anemia is commonly found. The leucocyte count is variable, and the erythrocyte sedimentation rate usually remains high. PATHOLOGY

The pathologic response in the tissues during the course of disseminated coccidioidomycosis presents a variability unusual in other diseases. When a mature spherule of Coccidioides ruptures and discharges endospores, an acute inflammatory response is induced in the immediate area; there is a suppurative reaction, with the collection of myriads of polymorphonuclear leucocytes. As each endospore enlarges, the reaction around it gradually becomes more chronic, and lymphocytes replace the polymorphonuclear cells; then macrophages appear, together with plasma cells and large mononuclear cells. Further growth of the spherule produces an ever more chronic infiltrate until epithelioid cells predominate, finally assuming a tuberculoid structure with giant cells in the center where the mature organism is found with its endospores. When the spherule ruptures the entire cycle is repeated. Thus, the general appearance microscopically is that of a tissue reaction of mixed type, varying from the most acute in one tiny area to the most chronic in another close by. When to the series just described is added the eosinophilic infiltrate so characteristic of the allergic erythema multiforme stage of primary coccidioidomycosis, it is realized that this disease runs the entire gamut of nonneoplastic pathologic infiltrations. Histopathologic study of material taken from the original chancre in the case of primary cutaneous coccidioidomycosis reported by Wilson, Smith, and Plunkett revealed a similar reaction of mixed type, varying from an

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acute inflammatory infiltrate in some areas, where polymorphonuclear cells predominated with some eosinophils and lymphocytes, to a chionic, granulomatous reaction in contiguous spots, where epithelioid cells, small lymphocytes, and giant cells were seen. With the exception of the eosinophils, these histopathologic features are commonly considered typical of coccidioidomycosis, regardless of the location or the type of infection. The coccidioidal* spherules were sparsely distributed and difficult to discover. The same pattern was observed in material taken from the regional lymph nodes. These features are at variance with those to be expected in primary chancres of other infectious granulomatous diseases, at least in the early phases when an acute reaction predominates and the causative organisms are present in large numbers. It is most important, however, to recall that the tissue examined in the case in question was not obtained until five weeks after the onset of the infection, by which time considerable involution had taken place. In comparison, a chancre due to syphilis would have similarly involuted during the same interval, so that the original acute phase of the inflammatory process would have become more chronic and the spirochetes would have been greatly reduced in number. Hence it does not seem warranted to conclude that the histopathologic studies in this case supplied evidence against an intracutaneous portal of entry, although it must be admitted that they did not assist in proving it. This question has now been solved by Trimble and Doucette, who were privileged to obtain specimens for histopathologic study very early in the course of the disease in their patient. They reported that the early phase was characterized by an acute inflammatory reaction, with fungus spherules numerous and easily seen. This finding is consistent with the picture to be expected in the primary chancriform stage of other diseases. Differential diagnosis Coccidioidomycosis should be suspected when any obscure illness occurs in a person who has previously lived in or visited one of the endemic areas. When mild, the primary pulmonary form may resemble the common cold, bronchitis, or influenza, and when more severe, may mimic pneumonia, neoplastic disease, tuberculosis, or almost any other pulmonary disorder. Disseminated coccidioidomycosis must be differentiated from other deep mycoses, tuberculosis, syphilis, and other granulomatous diseases. The diagnosis is established by demonstrating microscopically the causative organisms—typical spherules of Coccidioides immitis containing endospores in pus or exudate from lesions, or in histopathologic sections of diseased tissue—or by recovering the fungus in artificial culture or by animal inoculation. A patient who exhibits no reactivity to the skin test early in the course of a febrile illness, but develops positive reactivity later, may be accepted as having the disease. A positive reaction to the specific

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The systemic mycoses

complement-fixation test in more than small, doubtful concentrations indicates the presence of active coccidioidomycosis, as does a positive reaction to the coccidioidin precipitin test. MYCOLOGY It is not difficult to demonstrate C. immitis by direct microscopic examination of pus from cutaneous lesions or draining sinuses, but it is more troublesome to look for the organism in sputum, gastric contents, pleural exudate, or cerebrospinal fluid. Slides should be prepared in two ways. In the first, a drop of the suspected material is mixed with a drop of 10 percent K O H solution, covered with a cover slip, and gently heated. T h e organisms appear under subdued light as rounded bodies from 10 to 90 microns in diameter, with a thick, highly refractive double-contoured wall, thick in small spherules and thin in larger ones, which are stretched by many small globular endospores from 2 to 5 microns in diameter. In the second method, the slide really furnishes a miniature culture. A drop of the suspected material is diluted with a drop of normal saline and covered with a cover slip whose under edges have been coated with petrolatum by being drawn in turn over the thenar eminence of the palm, which has been coated with that material. Because this type of preparation does not dry out for several days at room temperature, time is allowed for sporulation of the fungus elements, and each spherule will produce several threadlike hyphae in two or three days. This method often furnishes a definitive diagnosis from one to several days earlier than other procedures. Coccidioides immitis is biphasic, reproducing in the tissues of infected animals in a manner entirely different from the way it reproduces in ordinary artificial culture. In the former (and in certain special types of culture) it forms only endospores borne in masses within spherules (called sporangia by those who class this fungus as a phycomycete). Each mother cell enlarges as the endospores multiply, until the walls become so thinned as to rupture, discharging the contents into the surrounding tissue. Each endospore enlarges in turn (often before it is discharged from its own mother cell), finally becoming a mature spherule. T h e entire cycle may be completed within a very few days, and is easily studied in histologic sections of tissues taken from the viscera of persons or animals who have died of the disseminated disease, for the organisms are present in great abundance in all stages of development. Occasionally the walls of pulmonary cavities, which are connected to the bronchial tree so as to become aerated, have been observed to support the fungus also in its hyphal stage, just as it grows in artificial culture. Although it is not really necessary to employ special staining procedures, because the ordinary H & E serves adequately, the periodic acid-Schiff stain shows morphologic details more clearly for teaching purposes. For artificial culture, Sabouraud's glucose agar suffices, and incubation

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is not necessary. Although the fungus grows slowly, it usually succeeds in spite of contamination by competitive organisms. T h e colony begins as a moist mat, resembling wet tissue paper, but soon a dry, aerial mycelium develops, white at first, but quickly turning dirty gray or brown. It might be described as "not well groomed, but moth-eaten." In contrast with other spherule-producing pathogenic fungi (Blastomyces dermatitidis, B. brasiliensis, Cryptococcus neoformans, and Histoplasma capsulatum, as well as with Sporotrichum schenckii), Coccidioides does not vary its method of growth to yield a yeastlike phase at incubator temperature. Most strains begin to sporulate in from three to fourteen days, and produce short, thickened, specialized hyphae, each bearing at the end a few arthrospores (jointed spores), somewhat resembling a string of beads. They are somewhat barrel-shaped, and are separated from each other by immitis a narrowed neck or collarette, which is distinctive for Coccidioides (compare with Geotrichum, which lacks this feature). Before accepting spores as being of the jointed variety it is advisable to see evidence of fragility at the joints by observing that they have actually broken apart; the hyphae of many fungi have cross walls dividing them into short segments, a feature that may be confusing. These arthrospores are the infecting form of the fungus. They are so light and easily broken away from the sporebearing stalk that a mere puff of wind can release a cloud of them from a culture and carry them for considerable distances. Great care must be exercised in the handling of cultures, for all nonimmune persons are in danger of becoming infected by inhaling the spores; infection has often occurred in this way, and on occasion has even been fatal. In the animal body the arthrospores enlarge and become spherules. If direct microscopic examination reveals only an occasional suspect structure, the special medium advocated by Ajello and Georg may be of assistance. Although those who are familiar with Coccidioides are seldom in doubt about its identity in culture after having studied its microscopic appearance, it is better to confirm the identification by animal inoculation of cultural material and microscopic examination of the resulting diseased tissues. IMMUNOLOGY T h e fungus Coccidioides immitis is probably as highly pathogenic to man as any other microbial organism. It seems able to infect all normal human beings who are adequately exposed, and to cause enough disease to produce demonstrable changes. Fortunately, it thrives in nature only in certain geographic localities, which are called epidemiologically "endemic." These regions form only a very small percentage of the land area of the world. Even though so limited, the disease has infected an estimated 10 million persons. T h e fungus has caused death comparatively rarely (perhaps in no more

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than a total of 3,000 instances), and serious illness in only a few thousand additional cases. Its virulence might therefore appropriately be described as slight, implying that the low fatality and morbidity rates are entirely attributable to its lack of disease-causing potency. Most of our evidence, however, suggests that this view is wrong, and that the rarity of death and of serious illness is in reality due to the ability of almost all human beings to react quickly to the presence of Coccidioides in susceptible tissues; they develop a high degree of specific immunologic resistance, sufficient in more than half of the cases to prevent any symptoms of illness, and to hold them to a minimum in most of the rest. This immunologic resistance not only protects from death all but an occasional person, but either cures a patient or assists other therapeutic measures sufficiently to do so. It also protects against reinfection (at least to any clinically observable degree) for many years, and probably for life. Viewed in this light, the specific immunologic resistance that develops in human beings infected by Coccidioides is almost perfect, failing in only a tiny fraction of 1 percent of the cases, and otherwise being effective, complete, and permanent. It seems obvious that the best subject with which to begin the study of immunology would be one that functions so nearly perfectly. Nevertheless, a great deal of immunologic research begins at the opposite pole, with the investigation of patients afflicted by diseases in which acquired specific immunologic resistance is absent or functions poorly. It is difficult to study coccidioidomycosis when it is being well resisted, because then it remains entirely subclinical. T h e only evidence that such an infection exists is the patient's ability to respond to the intracutaneous test with coccidioidin by producing an indurated erythematous papule of the delayed type, as observed typically in the tuberculin test. T h e coccidioidin skin test is sufficiently specific and consistent in its development to indicate that specific antibodies are being produced, and their production is a strong indication that the resistance is of the specific acquired type, and not simply a natural possession of the host. In most instances the ability to react to this test is retained for many years, perhaps for life, and such individuals do not again become infected by Coccidioides from external sources. A quiescent focus, however, may become more severe, a process that has been called endogenous reinfection in tuberculosis and histoplasmosis. By using several dilutions of coccidioidin, clinicians can make the skintest reaction somewhat quantitative. They have learned to use the height of this reaction as a measure of the patient's ability to resist the infection, and, although some discrepancies require further study, the degree of parallelism is remarkable. It is therefore natural to wonder whether or not the specific antibody revealed by the skin test is indeed responsible for the immunologic resistance; as yet there is no proof either way. In tuber-

Coccidioidomycosis

39

culosis a similar theory has been abandoned, but the tuberculin test is usually performed with a protein derivative, whereas coccidioidin is a polysaccharide, practically free of protein, and equally reactive when completely denitrogenized. On this point it is worth noting that polysaccharides from the tubercle bacillus have recently been shown to be more closely concerned in immunologic resistance to tuberculosis than the protein fractions previously used for the tuberculin test. The antibody revealed by the coccidioidin skin test is not present in blood serum, although it may be carried in the circulating blood by leucocytes. It is mainly demonstrable in the skin, although intravenously administered coccidioidin may cause fever and joint pains, indicating that the skin is not the only tissue that may be affected. It is difficult to believe that an antibody located principally in the skin can be so remarkably efficient in resisting coccidioidomycosis, a disease that is almost always acquired by inhalation, with the lungs as the shock tissue. It may be that any body tissues that are attacked can be quickly supplied with antibodies through the mediation of leucocytes, no matter where their production or storage actually takes place. Two other specific antibodies are produced by the human body in response to coccidioidal infection, but they do not seem able to assist in immunologic resistance. The complement-fixation reaction, using coccidioidin as the antigen, often reveals the presence of a specific antibody in human serum, frequently in high titer when quantitated, and in sufficient quantity to cause high levels of gamma globulin. It is difficult to believe that this factor assists in immunologic resistance because it is often delayed for several weeks after the infection, frequently never appears at all in the most perfectly resisted subclinical cases, and increases higher and higher in titer as the patient approaches death. In fact, this titer has long been used by clinicians as a rough measure of the extent of the disease, of the quantity of involved tissue, or of the number of fungal organisms actively involved at that time in causing the disease. It must therefore be interpreted as almost the opposite of a measure of resistance. Perhaps this antibody is intended by nature to contribute toward resistance, but it fails to do so because of some imperfection. It is not simply an altered form of the antibody revealed by the skin test, for either or both may be high or low independently of each other, and there is no evidence that one can be converted to the other, either in part or totally. The third specific antibody is revealed in serum by a precipitin reaction, using coccidioidin as the antigen. It appears consistently early in the course of the infection, often even before the skin test becomes positive, but it disappears after the first few months regardless of whether the patient is destined to die of the disease or to resist it well enough to remain entirely free of symptoms, and become permanently immune. This antibody therefore cannot be the factor that confers immunologic resistance.

40

The systemic mycoses

It is not of value in prognosis, except that Winn considers its undue persistance a sign of added severity, warranting more strenuous drug therapy than might otherwise be indicated. The clinician can thus use the height of skin reactivity as a rough measure of the host's resistance ability, and the complement-fixation titer as a measure of the extent and the severity of the disease. In ascertaining the prognosis, the interplay of these tests should be given even more consideration than symptoms, signs, and other laboratory procedures, including radiographs. During the course of the disease these tests should be repeated at intervals lengthening from two weeks to two months, so that any complications tending toward a worsening prognosis may be discovered early and combated. Perhaps there is yet another antibody produced in cases of coccidioidomycosis. When the coccidioidin skin test is performed, an urticarial wheal or immediate flare reaction is often observed, regardless of whether or not the aforementioned delayed tuberculin type of response is due to follow. It has not been possible, however, to relate this immediate reaction to the course of the disease or to the patient's immunologic status in any way, nor to prove that it is or is not a stage in the development of the important tuberculin type of response. As it is not consistently present in highly immune persons, nor absent in those near death, it is not the immunity factor. Work in progress at the University of California, Los Angeles, based on gel-diffusion techniques, seems to indicate that not one, but several, antibodies are concerned with each of the previously mentioned testing procedures, the analysis of which may lead to better understanding. If we could establish an antibody as the factor responsible for the immunologic resistance produced by normal human beings when infected by Coccidioides, and prove where it is formed and stored, we might then be able to discover the defect or defects in the immunologic mechanisms which prevent the occasional patient from developing the antibody, and thereby cause him to become seriously ill or to die. Some of these defects may be correctable if completely understood. We might also be able to stimulate the production of the antibody by nonspecific means, or by specific means such as an effective vaccine. It is significant, however, that most of the victories won by vaccines have occurred when normal, uninfected individuals were vaccinated and thereby rendered resistant to a subsequent challenge by the specific microbe. There have been no comparable successes when the specific vaccination was begun after the patient was already diseased. A patient afflicted with serious disseminated coccidioidomycosis has already demonstrated that he is not normal immunilogically; otherwise he would earlier have developed specific antibodies to an effective degree. It is discouragingly necessary to point out that this defect might also prevent him from responding to an artificially produced vaccine.

Coccidioidomycosis

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If we knew where the specific antibody is stored in resistant individuals, we might obtain it from them and perhaps concentrate it, and then administer it to nonresistant individuals. This process could furnish a passive specific resistance that might keep the disease from becoming severe or fatal long enough for the patient's own immunologic mechanism to recover and develop the more valuable and permanent active resistance. It is possible that this result has already been achieved to some extent, because it has long been known that frequent small transfusions of whole blood are helpful in serious coccidioidomycosis; in endemic regions the donors are likely to have had the infection and recovered, and therefore to possess immune bodies either in serum or in leucocytes, if in fact they are carried there. As yet no concerted effort has been made to prove this theory. Some deep fungous infections, notably histoplasmosis and cryptococcosis, are accompanied by disease of the reticuloendothelial system in a statistically significant percentage. This fact suggests that the lack of resistance is due to the failure of the reticuloendothelial system to produce specific antibodies. In coccidioidomycosis there is no such relationship. Nor is diabetes an accompaniment frequently enough to suggest the causal relationship that is so marked in mucormycosis and moniliasis. The most impressive clue to the nature of the immunologic defect in serious or fatal coccidioidomycosis is its increased incidence in persons with darkly pigmented skin. Except during pregnancy, females resist the disease much better than males. Dietary deficiencies, particularly of protein and vitamin C and the B group, are important contributors to lack of resistance. There is no significant relationship with neoplastic disease. Corticosteroid therapy, though said to be harmful to developing resistance, has often been used without serious sequelae; its status is somewhat in doubt at present. Five percent of the persons who have largely recovered from primary pulmonary coccidioidomycosis have residual lesions, but their existence does not necessarily indicate a high level of activity, and only rarely does progressive disease result again after such focalization is complete. According to Winn, surgical removal of pulmonary cavities or abscesses should be considered if repeated pulmonary hemorrhage occurs; if cavities or abscesses continue to enlarge, threaten to rupture through the pleura, or become secondarily infected; or if a solid nodule softens and excavates. These lesions are not usually responsive to amphotericin B alone, but the drug serves as a fungistatic cover for the surgery. The percentage of cases in which surgery is employed varies considerably. So long as each follow-up examination reveals a reasonable degree of improvement clinically and radiologically, especially if the skin-test reactivity is high, and the complement-fixation titer with coccidioidin and the sedimentation rate are diminishing, surgical intervention appears

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The systemic mycoses

to be unnecessary and may be harmful. In some surgical services skintesting and complement-fixation procedures are not considered important enough to be reported or even to be performed, leaving considerable doubt as to the status of the patients in the minds of those w h o do have faith in the prognostic value of such procedures. Many such cases might have improved as much, or even more, if surgery had been avoided. After removal of a diseased lobe, the expansion of the remaining lung area may cause new cavitation or reveal previously unrecognized cavities. Coin-shaped lesions that cannot be ruled as nonmalignant urgently demand diagnostic study through surgery, and even advocates of skintesting and complement-fixation procedures do not advise that they be considered conclusive in such a situation. N o matter what the tests reveal, carcinoma may be present; the tests show only the coccidioidal status. Empyema or nonexpansile areas of lung probably are also valid reasons for surgery. Dissemination is the most serious aspect of coccidioidomycosis. It is usually heralded by a complement-fixation titer with coccidioidin of more than 1:32, but it may occur without such elevation if only small foci are being established by dissemination. It is therefore important to watch carefully for any sign, however small, that an extrapulmonary lesion is developing. In some regions, notably the central nervous system, even a tiny focus of disseminated disease may quickly be fatal. THERAPY Disseminated coccidioidomycosis carried a fatality rate of about 50 percent, in spite of all available treatment, until the advent of amphotericin B. T h i s drug is useful beyond all doubt, but it is too toxic to be employed indiscriminately. T h e enthusiasm that greeted its discovery soon waned because of its undesirable side effects, but additional experience in its use has made for better control, and the drug is again gaining in popularity. T h e details of its administration, as given by W i n n in the chapter devoted to treatment of fungous diseases as a group, seem to promise greater safety than has been achieved on the average, and should be scrupulously observed. In highly experienced hands the drug may be utilized in cases where otherwise it might prove to be more dangerous to the patient than the disease itself. W i n n recommends it "for controlling severe primary coccidioidomycosis; for use routinely during pregnancy; for arresting disseminated disease, especially meningitis; for the healing of persistent peripheral granulomas and abscesses; for preparing patients for surgery and for covering it protectively to avoid the occasional severe complications." W i n n also recommends serious consideration of amphotericin B for use even in less severe forms occurring in Filipinos, Negroes, and Mexicans, who are racially more susceptible to dissemination. A t least one month

Coccidioidomycosis

43

of intravenous amphotericin B is indicated, and, because its action against Coccidioides immitis is fungistatic rather than fungicidal, it is often necessary to extend the treatment by another one or two months. Coccidioidal meningitis, usually fatal within a year if untreated, is definitely improved by amphotericin B administered by the combined intravenous and intrathecal routes. Early recognition is important to prevent delay in treatment. Examination of the spinal fluid is indicated in all primary infections that are unduly severe or prolonged. In addition to the usual findings confirming meningitis, the spinal fluid will fix complement pathognomonically with coccidioidin in 75 percent of the cases. Culture is also useful. Intravenous amphotericin B should be increased to maximal amounts as soon as possible, augmented by intrathecal administration of the same drug twice weekly (or occasionally on alternate days), beginning with 0.01 mg dissolved in 2 to 3 cc of spinal fluid or distilled water and increasing the dose to a maximum of 0.5 mg as tolerated. Unfortunately, a subacute chemical arachnoiditis, called Froin's syndrome, often results from this treatment, making continuance of it difficult or impossible. One patient developed a complete transverse myelitis. Winn believes that alternating or intensively combining the spinal with the intracisternal route, using a maximum of 0.75 mg for the latter, decreases this hazard and may account for the better results he obtained by continuing the treatment for the recommended minimum of three months. T h e latter route also appears to provide a more direct approach to the dangerous area of the infection, the base of the brain. Winn's intensive regimen includes injections intraspinally on Mondays, Wednesdays, and Fridays, and intracisternally on Tuesdays and Thursdays. Although many cases of meningitis have shown dramatic clinical improvement during this therapy, even to apparent complete recovery, relapses have been frequent; to prevent them Winn advocates intracisternal treatment once a week for a prolonged time. He has found it practicable even for outpatients. It is too early to evaluate the results accurately, but the attempt to fight an otherwise almost invincible enemy is laudable. Amputation, formerly employed for coccidioidomycosis of arms or legs, served well only if the infection was actually confined to removable regions. More recently, some of these cases have yielded to amphotericin B; if this treatment failed, a trial was given to isolating the limb from the general circulation and perfusing it by means of a heart-lung machine with blood containing a higher percentage of the drug than could safely be maintained otherwise (Newcomer). T h e results have not been encouraging, and in some cases the attempt has resulted in thrombosis of frightening severity. Although many patients have improved during recent therapy for serious degrees of coccidioidomycosis, it must be recalled that some, perhaps half, of any such group would have been expected to do so under any

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The systemic mycoses

regimen. It is a source of worry to observe that many patients have become clinically well while still maintaining too much reactivity to complement fixation and too little to the skin test, indicating a less than perfect immunological victory, and suggesting that, as the patient is still susceptible, even a few viable fungi left may cause relapse at any time. Because amphotericin B is not ideal in the treatment of coccidioidomycosis, experimentation with other drugs should not cease. Such work should be done only on new, as yet untested, materials, for the older ones have already been proved less efficient than amphotericin B. A new crystalline antifungal antibiotic called pimaricin, derived from Streptomyces natalensis, is currently being investigated. Effective in vitro against Coccidioides, it has been clinically tried on two patients (Newcomer). It was well tolerated, and the lesions in one case cleared during therapy. Vaccine therapy, as formerly advocated, has been entirely abandoned. Studies in this direction are continuing, but have not yet reached a practical stage. It must be emphasized that the persons who really need help are immunologically deficient and might well be unable to respond to any artificial vaccine, even as they do not respond to the infection itself. Bibliography Albert, B. L., and T . F. Sellers, Jr. 1963. Coccidioidomycosis from fomites. Arch. Intern. Med., 112:253. Almeida, F. P. de. 1930a. Comparative study of coccidioidal granuloma in the United States and Brazil, establishing a new genus for the Brazilian parasite. [In Portuguese.] An. Fac. Med. Univ. Sao Paulo, 5:125. . 19306. Differential features of the etiologic agents of coccidioidal granuloma of the United States and Brazil. [In French.] Compt. Rend. Soc. Biol., 105:315-316. Bacharach, T . , and E. G. Zalis. 1963. Sarcoid syndrome associated with coccidioidomycosis. Amer. Rev. Respir. Diseases, 88:248. Baker, E. E., E. M. Mrack, and C. E. Smith. 1943. T h e morphology, taxonomy and distribution of Coccidioides immitis. Farlowia, 1:99. Baker, E. E., and C. E. Smith. 1942. Utilization of carbon and nitrogen compounds by Coccidioides immitis. J. Infect. Diseases, 70:51. Baker, K. C., and S. R. Kemberling. i960. Coccidioidal granuloma after treatment with amphotericin B. Arch. Dermatol., 81:373. Benham, R. W. 1934. Fungi of blastomycosis and coccidioidal granuloma. Arch. Dermatol. Syphil., 30:385. Campbell, C. C., and G. E. Brinkley. 1953. Serologic diagnosis of histoplasmosis, coccidioidomycosis and blastomycosis, and the probability of cross reactions. J. Lab. Clin. Med., 42:896. Campins, H. 1961. Coccidioidomycosis: commentaries on Venezuelan casuistics. [In Spanish.] Mycopathologia, 15:306. Cooke, J. V. 1915. Immunity tests in coccidioidal granuloma. Arch. Intern. Med., i5:479-

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Cotton, B. H., and J. W. Birsner. 1959. Surgical treatment of pulmonary coccidioidomycosis. J. Thorac. Cardiovasc. Surg., 38:435. Curran, W . S., and A. W . Williams. 1963. Eosinophilic pleural effusion, a clue in differential diagnosis. Arch. Intern. Med., 111:809. Dickson, E. C. 1937. "Valley Fever" of San Joaquin Valley and the fungus Coccidioides. Calif. West. Med., 47:151. . 1938. Primary coccidioidomycosis. J. Amer. Med. Assoc., 111-1362. Dickson, E. C., and M. A . Gifford. 1938. Coccidioidomycosis: primary type of infection. Arch. Intern. Med., 62:853. Diven, R. H. t and R. E. Reed. 1962. Serum protein: patterns in experimental coccidioidomycosis. Proc. Soc. Exptl. Biol. Med., 111:503. Einstein, H. E., C. W. Holeman, L. L. Sandige, and D. H. Holden. 1961. Coccidioidal meningitis: the use of amphotereicin B in treatment. Calif. Med., 94:339Emmons, C. W . 1942. Isolation of Coccidioides from soil and rodents. Public Health Repts., 57:109. Emmons, C. W., and W . R. Piggott. 1962. Combined therapy of experimental coccidioidomycosis with X-5079C and amprotericin B. Antibiotics and Chemotherapy, 12:371. Fiese, M. J. 1957. Treatment of disseminated coccidioidomycosis with amphotericin B. Calif. Med., 86:119. Friedman, L., C. E. Smith, and R. J. Berman. 1962. Studies on the survival characteristics of the parasitic phase of Coccidioides immitis, with comments on contagion. Amer. Rev. Respir. Diseases, 85:224. Gifford, M. A. 1935-36. San Joaquin "Valley Fever" and the fungus Coccidioides. Ann. Rept. Kern County (Calif.) Health Dept.:22. Gifford, M. A., W C. Buss, and R . T . Douds. 1936-37. Coccidioidomycosis. Ann. Rept. Kern County (Calif.) Health Dept. Goodman, D. H., and C. Schabarum. 1963. Primary cutaneous coccidioidomycosis: visible classic demonstration of delayed hypersensitivity. Ann. Intern. Med., 59:84. Guy, W. H., and F. M. Jacob. 1927. Granuloma Coccidioides. Arch. Dermatol. Syphil., 16:308. Harrell, E. R., and W . M. Honeycutt. 1963. Coccidioidomycosis: a traveling fungus disease. Arch. Dermatol., 87:188. Hassid, W. J., E. E. Baker, and R . M. McCready. 1943. Immunologically active polysaccharide produced by Coccidioides immitis. J. Biol. Chem., 149:303. Hirsch, E. F. 1923. Skin reactions in coccidioidal granuloma. Trans. Chicago Pathol. Soc., 12:335. Hirsch, E. F., and D. d'Andrea. 1927. Specific substance of Coccidioides immitis. J. Infect. Diseases, 40:634. Hunter, R. C., and E. S. Mongan. 1958. Disseminated coccidioidomycosis treated with amphotericin B. U.S. Armed Forces Med. J., 9:1474-1486. Huppert, M., L. J. Walker, and J. W . Bailey. 1962. Complement fixation for coccidioidomycosis on spinal fluids filtered through molecular membranes. J. Bacteriol., 83:693. Kessel, J. F. 1939. Coccidioidin skin test. Amer. J. Trop. Med., 19:199.

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Klapper, M. S., D. T . Smith, and N. F. Conant. 1958. Disseminated coccidioidomycosis apparently cured with amphotericin B. J. Amer. Med. Assoc., 167:463. Levan, N. E., and M. Q. Kwong. 1963. Coccidioidomycosis: occupational aspects. Arch. Dermatol., 87:511. Littman, M. L. 1957. Preliminaary observations on the intravenous use of amphotericin B in the therapy of chronic coccidioidal osteomyelitis. Proc. Sympos. Coccid. (Feb. n-i3):86. Littman, M. L., P. L. Horowitz, and J. G. Swadey. 1958. Coccidioidomycosis and its treatment with amphotericin B. Amer. J. Med., 24:568. Maddy, K. T., H. G. Crecelius, and R. G. Cornell. 1961. Where can coccidioidomycosis be acquired in Arizona? Ariz. Med., 18:184. Melick, D. W. 1958. The surgical treatment of pulmonary coccidioidomycosis, with a comprehensive summary of the complications following this type of therapy. Amer. Rev. Tuberc. Pulmon. Diseases, 77:17. Mendenhall, J. C., W. C. Black, and G. E. Pottz. 1948. Progressive (disseminated) coccidioidomycosis during pregnancy. Rocky Mountain Med. J., 45:472. Newcomer, V. D., J. W. Landau, M. D. Lehman, and J. R. Rowe. 1963. The local cellular response in patients with coccidioidomycosis. Arch. Dermatol., 88:799. Ophtils, W. 1905. Further observations on a pathogenic mould formerly described as a protozoon (Coccidioides immitis, Coccidioides pyogenes). J. Exptl. Med., 6:443-485. Ophiils, W., and H. S. Moffitt. 1900. A new pathogenic mould, formerly described as a protozoon: Coccidioides immitis pyogenes. Phila. Med. J., 5:14711472. Pappagianis, D., E. W. Putnam, and G. S. Kobayashi. 1961. Polysaccharide of Coccidioides immitis. J. Bacteriol., 82:714. Posadas, A. 1894. Contribution to the study of the etiology of tumors: generalized infectious psorospermosis. [In Spanish.] Unpublished thesis. Buenos Aires. Reed, W. B., C. L. Heiskell, C. W. Holeman, and C. M. Carpenter. 1962. Serum protein profiles in coccidioidomycosis. Calif. Med., 97:333. . 1963. Serum profiles in coccidioidomycosis. J. Invest. Dermatol., 40:147. Rixford, E., and T . C. Gilchrist. 1896. Two cases of protozoan (coccidioidal) infection of the skin. Repts. Johns Hopkins Hosp., 1:209. Rowe, J. R., V. D. Newcomer, and J. W. Landau. 1963. Effect of cultural conditions on the development of antigens by Coccidioides immitis. I. Immunodiffusion studies. J. Invest. Dermatol., 41:343. Rowe, J. R., V. D. Newcomer, and E. T . Wright. 1963. Studies of the soluble antigens of Coccidioides immitis by immuno-diffusion. J. Invest. Dermatol., 41:225. Schubert, J. H., and C. R. Hampson. 1962. An appraisal of serologic tests for coccidioidomycosis. Amer. J. Hyg., 76:144. Skipworth, G. B., J. J. Bergin, and R. M. Williams, i960. Coccidioidal granulomas of skin and conjunctiva treated with intravenous amphotericin B. Arch. Dermatol., 82:605. Smale, L. E., and J. W. Birsner. 1949. Maternal deaths from coccidioidomycosis. J. Amer. Med. Assoc., 141:212.

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Smith, C. E. 1940. Epidemiology of acute coccidioidomycosis with erythema nodosum. Amer. J. Public Health, 30:600. . 1956. Pattern of 39,500 serologic tests in coccidioidomycosis. J. Amer. Med. Assoc., 160:546. Smith, C. E., R. R. Beard, E. G. Whiting, and H. G. Rosenberger. 1946. Varieties of coccidioidal infection in relation to the epidemiology and control of the disease. Amer. J. Public Health, 36:1394. Smith, C. E., D. Pappagianis, H. B. Levine, and M. T . Saito. 1961. Human coccidioidomycosis. Bacteriol. Rev., 25:310. Smith, C. E „ M. T . Saito, R. R. Beard, R. Mc. Kepp, R. W. Clark, and B. V. Eddie. 1950. Serologic tests in the diagnosis and prognosis of coccidioidomycosis. Amer. J. Hyg., 52:1. Smith, C. E., E. G. Whiting, E. E. Baker, H. G. Rosenberger, R. R. Beard, and M. T . Saito. 1948. T h e use of coccidiodin. Amer. Rev. Tuberc. Pulmon. Diseases, 57:339. Sorensen, L. J., E. G. McNall, and T . H. Sternberg. 1959. T h e development of strains of Candida albicans and Coccidioides immitis which are resistant to amphotericin B. Antibiot. Ann., 1958-59:920. Sternberg, T . H., V. D. Newcomer, E. T . Wright, E. G. McNall, L. J. Sorensen, and R. M. Reisner. 1958. T h e treatment of disseminated coccidioidomycosis with amphotericin B. Ann. Meeting Amer. Acad. Dermatol., Chicago (Dec.). Stewart, R. A., and K. F. Meyer. 1932. Isolation of Coccidioides immitis from soil. Proc. Soc. Exptl. Biol. Med., 29:937. Tarbet, J. E., and A. M. Breslau. 1953. Histochemical investigation of the spherule of Coccidioides immitis in relation to host reaction. J. Infect. Diseases, 92:183. Tarbet, J. E., E. T . Wright, and V. D. Newcomer. 1952. Experimental coccidioidal granuloma: developmental stages of sporangia in mice. Amer. J. Pathol., 28:901-917. Vaughan, J. E., and H. Ramirez. 1951. Coccidioidomycosis as a complication of pregnancy. Calif. Med., 74:121. Wernicke, R. 1892. tJber einen Protozoenbefund bei Mycosis Fungoides. Zentr. Bakteriol., 12:859. Williams, R. M., and G. B. Skipworth. 1958. Treatment of disseminated coccidioidomycosis with amphotericin B. Arch. Dermatol., 78:97. Wilson, J. W. 1953. Coccidioidomycosis as a tool in the study of granulomatous disease. Calif. Med., 78:257. . 1962. Factors which may increase the severity of coccidioidomycosis. Lab. Invest., 11:1146. . 1963. Cutaneous (chancriform) syndrome in deep mycoses. Arch. Dermatol., 87:81. Wilson, J. W., C. E. Smith, and O. A. Plunkett. 1953. Primary cutaneous coccidioidomycosis: the criteria for diagnosis. Calif. Med., 79:233. Winer, L. H. 1950. Histopathology of the nodose lesion of acute coccidioidomycosis. Arch. Dermatol. Syphil., 61:1010. Winn, W. A . 1951. Coccidioidomycosis and pulmonary cavitation. Arch. Intern. Med., 87:541. . 1957a. Coccidioidomycosis. J. Chron. Diseases, 5:430-444.

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. 1957b. The clinical development and management of coccidioidomycosis. Proc. Sympos. Coccid., U.S. Public Health Serv., Publ. no. 575. . 1958. Roentgenology of the chest. Chap. 16. Springfield, 111.: Charles C Thomas. . 1959. The use of amphotericin B in the treatment of coccidioidal disease. A m e r . J . M e d . , 27:617. . i960. Coccidioidomycosis: the need for careful evaluation of the clinical pattern and anatomical lesions. Arch. Intern. Med., 106:463. . 1962. The diagnosis and treatment of coccidioidomycosis. Ariz. Med., 19:211.

Winn, W. A., H. B. Levine, J . E. Broderick, and R. W. Crane. 1963. A localized epidemic of coccidioidomycosis in a group of ten children. New Engl. J . Med., 268:867.

5 Sporotrichosis

INTRODUCTION is an infectious disease which develops in man and animals as the result of acquiring spores of Sporotrichum schenckii from an exogenous source in nature. In sharp contrast with the inhalation portal of entry for coccidioidomycosis, histoplasmosis, blastomycosis, and probably some of the other deep mycoses, in sporotrichosis the organism enters almost invariably through a break in the skin, such as a scratch or a puncture wound. T h e syndrome that develops subsequently so closely resembles the primary stage of cutaneously acquired syphilis that it is termed "chancriform." Much more rarely, a generalized infection occurs. Recent clinical, epidemiological, and immunological comparisons of this deep mycosis with the others have shown that many of the differences are only apparent, and that the fundamental pathogenetic and immunologic processes are probably almost identical. SPOROTRICHOSIS

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50

T h e systemic mycoses

HISTORY Although a disease that was almost certainly sporotrichosis was described as early as 1809 by Link, and by Lutz in 1889, Schenck's first report on this deep mycosis in 1898 was sufficiently thorough to establish a clinical picture almost as complete as it is today. In a series of important papers beginning in 1903, de Beurmann, collaborating with Ramond, Gougerot, and others, contributed many facts about the fungus, and also described the uncommon generalized type of the infection. In 1910, when more than a hundred cases had been reported, Hyde and Davis published an extensive review with more than 150 references. In 1927 Pijper and Pullinger reported fourteen cases resulting from injuries sustained by native workers through contact with the timbers in South African mines. T h u s began a surprisingly extensive epidemic, totaling almost 3,000 cases by 1944 (Dangerfield and Gear; Helm and Berman). A n extremely valuable study covering-this epidemic was published as a monograph by the Transvaal Mine Medical Officers Association in 1947. T h e list of cases is still being augmented. During the past fifteen years the immunologic aspects of sporotrichosis have been clarified by the work of Norden (1915) and of Gonzalez-Ochoa and Figueroa, and more recently by Pereira, Padilha-Gon^alves, Lacaz, Fava-Netto, and Martins de Castro. ETIOLOGY It is generally accepted that only a single species of fungus, Sporotrichum schenckii (originally called Sporothrix, and perhaps significantly, because recent investigations seem to support the correctness of that term), is capable of causing sporotrichosis. T h i s dimorphic organism grows in culture in a yeastlike form at incubation temperature, and in a filamentous phase at room temperature. T h e r e is considerable variation in color production among different strains. DISTRIBUTION It has not been possible to define any geographic limitations for the disease, as sporotrichosis exists wherever there are personnel capable of making the diagnosis. T h e fungus has been found widely distributed in nature, especially as a saprophyte on vegetation living or dead, and in animal excreta. Certain circumstances apparently enhance its growth in a particular environment; for example, Brown discovered that it grew on mine timbers only where the temperature was between 79 0 and 84° F, and where the relative humidity did not fall below 92 percent. N o age group is exempt, and there seems to be no variation in suscepti-

51

Sporotrichosis

bility because of race or color of skin. T h e definite predominance of the disease in males between twenty and fifty years of age is almost certainly attributable to the increased likelihood that they will sustain cutaneous injury during work or play. Padilha-Gon^alves and Peryassu, however, have consistently observed that a significantly higher percentage of females in Brazil acquire the disease, indicating that local conditions may reverse the usual trend. EPIDEMIOLOGY Sporotrichosis occurs frequently in horses, and less often in dogs, cats, rats, and mice. Direct transmission from such animals (by rat or parrot bites, for example) has been reported. Rarely is the disease transferred from man to man. L. M. Smith accepted one such instance, when the cheek of an infant had apparently been directly infected from the cheek of the mother. Vegetation, either living or dead, is the usual reservoir in nature; such material is particularly dangerous when it contains sharp objects such as splinters, thorns, or rough bark capable of inflicting deep cutaneous injury and implanting bits of infected plant material in the wounds. T h e fungus has been successfully cultured on carnations by Benham and Kesten. T h e barberry shrub was responsible for many cases reported by Foerster, and sphagnum moss infected florists, as observed by Gastineau, Spolyer, and Haynes. In a few instances laboratory personnel have become infected when handling cultures. According to Dangerfield and Gear, the incubation period is from three days to three weeks. CLINICAL

CHARACTERISTICS

In their extensive writings, de Beurmann and Gougerot classified sporotrichosis into six clinical types (lymphatic, disseminated, epidermal, mucosal, skeletal, and visceral), although in many cases the lesions were characteristic of more than one type. Such a multiplicity of forms seems unnecessary. Lesions of all these classes, in various combinations, have long been recognized in most of the other deep mycoses, and in none of them has it been found desirable to set u p separate clinical categories. T h e localized type of sporotrichosis resulting from direct primary inoculation into the skin is certainly distinct, as is the disseminated form; most of the other classes are probably variants of one or the other of these two forms, and are so treated here. Primary cutaneous sporotrichosis Primary cutaneous sporotrichosis results when Sporotrichum schenckii is inoculated directly into the skin of a previously uninfected person. Such inoculation almost always comes from an injury sustained by contact

52

T h e systemic mycoses

with wooden splinters, thorns, or other vegetation. Sometimes, however, there is no history of cutaneous injury, and penetration through the walls of intact hair follicles is considered probable. After an incubation period of from three to twenty-one days (or sometimes of several months) an elevated papule appears, pink or cyanotic in color, frequently oval in shape with its long axis aligned with the natural skin creases. In 60 percent of the 2,825 cases studied by Helm and Berman, the initial lesion was on the hand or the arm; in 23 percent, on the trunk; in 11 percent, on the legs; in 2 percent, on the face or neck; and in the remainder multiple lesions were present. Evidently other areas of the body were not involved mainly because of the protection afforded by the type of clothing worn by native miners. It is remarkable that in most instances the primary lesion is not painful unless it is accompanied by secondary bacterial infection. Usually there is little exudate. The papule slowly enlarges and begins to ulcerate in the center, eventually forming a crater with a bright-red base free of necrotic tissue, and with ragged, undermined edges, which bleeds easily when traumatized. Frequently similar small secondary papules appear at the periphery. After a week or more, most patients begin to develop nodules along the lymphatic channels that drain the area. These nodules are small and demonstrably subcutaneous at first, but they rapidly enlarge and soon become attached to the skin. Surprisingly, a nodule farther from the original chancre is sometimes more advanced than closer ones. Lymphangitis also develops in these vessels. The nodules frequently ulcerate, until they appear as miniatures of the parent chancriform lesion. The regional lymph nodes become enlarged, but usually do not ulcerate. As a rule the general health of the patient is not affected, and this fact, together with the strict localization to the originally affected region, indicates that a high level of resistance has been developed. The resistance, however, is ordinarily not sufficient to effect complete, spontaneous cure. Lymphatic involvement, though typical of sporotrichosis, is minimal or even absent in some cases. The disease spreads in the skin itself, forming a flat plaque, sometimes smooth, sometimes covered with silvery scales. A warty form is occasionally seen, most often on forehead or knee. Sometimes warty growths become extensive and are accompanied by pustules, simulating verrucous tuberculosis or blastomycosis (Smith and Garrett). Variations like these are probably owing to factors as yet little understood, such as local tissue resistance, specific or nonspecific general body resistance, and possibly the depth, quantity, and virulence of the original inoculation. According to Helm and Berman, experimental infections in human beings suggest that intradermal inoculation may produce the mild superficial plaque type, and that the subcutaneous route produces the ulcerative and lymphatic form. Even more logical is the belief that the latter type results from a changed pathogenesis in a particular patient who

Sporotrichosis

53

had perhaps been previously infected with sporotrichosis which had healed before the subsequent inoculation occurred, creating partial immunologic resistance (Pereira et al., 1962a). Verrucous lesions may be caused by dissemination from a previously unrecognized internal focus, as is thought to occur more commonly in several other deep mycoses. Carr, Storkan, Wilson, and Swatek (1964) reported a case of extensive verrucous sporotrichosis which lasted for twenty-one years without affecting the patient's general health. This case history conforms closely to the course of many similar cases of North American blastomycosis. Sporotrichosis occasionally begins in the mucous membrances of nose, mouth, or pharynx. Sometimes the subsequent clinical picture is chancriform, and results in regional lymphatic involvement in a manner strongly suggesting that the primary inoculation occurred through the mucous membranes, just as the primary cutaneous form does. Other cases suggest that such lesions originated by dissemination from within, because other internal organs were simultaneously affected. Nontegumentary primary sporotrichosis It is highly significant that among the almost 3,000 cases of sporotrichosis occurring in the African mines, with all the evidence indicating that the infection occurred by intracutaneous primary inoculation, not one showed dissemination to other organs. If the concept suggested by this trend is correct, that only the chancriform syndrome or the chronic verrucous form, without systemic dissemination in either case, develops from a direct cutaneous primary inoculation, it seems necessary to postulate a nontegumentary portal of entry to explain the rare disseminated form (discussed below). Conclusive proof of this theory is difficult to obtain. De Beurmann demonstrated that S. schenckii would pass unaffected through the intestinal mucosa when ingested on contaminated raw fruits or vegetables, but cases exhibiting lesions of the gastrointestinal tract are very rare. Long ago de Beurmann and Gougerot demonstrated in experiments on animals that percutaneous inoculations produced localized cutaneous forms, whereas inoculations made intraperitoneally or into the mucous membranes of the digestive system produced disseminated disease. In none of the disseminated cases reviewed by Collins was the initial lesion known to have been cutaneous. Lavalle (i960) believes that the portal of entry in the disseminated form is respiratory. Simpson reports that the infectivity of cultures was retained, although in lessened degree, after two years of drying, and that on one occasion the fungus was recovered on a plate exposed to air currents in a mine shaft, indicating at least a possibility that the infection could be acquired by inhalation. It may not be necessary, however, to have a nontegumentary portal of entry. T h e correct answer may be the one that is believed to apply to coccidioidomycosis, where dissemination seems to occur only in a very small percentage of infected persons (about one per thousand), and only

54

The systemic mycoses

because the immunity mechanisms of these individuals were defective, perhaps even before the inoculation occurred. In coccidioidomycosis it is likely that this percentage would be similar in both the primary pulmonary type and the primary cutaneous form, although it has not as yet been conclusively demonstrated for the latter. Yet, if this theorizing is correct, it does seem likely that at least one or two cases of dissemination would have been discovered in almost 3,000 cases of sporotrichosis. A definitive answer must await the compiling of further data. Disseminated sporotrichosis

First, it is necessary to differentiate dissemination from the rather extensive spread of the typical intracutaneously acquired chancriform lesions into the regional lympathic structures. T h e term "dissemination" means the scattering of the infection widely over areas of the body far distant from the primary lesion through organisms carried by the bloodstream, as is typical of coccidioidomycosis. Disseminated sporotrichosis has rarely been reported, although cases that were never correctly diagnosed probably existed. T h e majority of the reported cases occurred in France in earlier years, but sporotrichosis has almost completely disappeared there in the past ten years (Drouhet). T h e writings of de Beurmann are the best source of information. Foerster, Moore and Kile (1935), Collins, and Cawley have recorded this type in America; Gonzalez-Ochoa, in Mexico; Rabello and Lisboa Miranda, in Brazil. T h e manner in which the infection was originally acquired has usually been obscure, but enough instances of involvement of mouth, pharynx, or lungs have been observed to suggest that these routes are the likely ones. In its most common form, disseminated sporotrichosis becomes apparent as multiple subcutaneous nodular masses scattered over the body, which soften and then, after incision or traumatic rupture, form chronic ulcers. From these the infection tends to spread over larger areas of the surrounding skin, simulating the lesions of tertiary syphilis, tuberculosis, or the other deep mycoses. Spontaneous cure is rare, and response to treatment has been poor, but somewhat variable. Some cases progress rapidly to death, while others remain chronic for months. Other parts of the body, such as bones, joints, muscles, tendon sheaths, lungs, meninges, the genitourinary system or other viscera, are often involved, sometimes in conjunction with the cutaneous abscesses, sometimes without them. PATHOLOGY

T h e pathologic tissue changes in primary cutaneous sporotrichotic lesions in human beings have one outstanding characteristic: the causative organisms are almost never recognizable as such (if indeed they are visible at

5. Sporotrichosis: primary cutaneous (chancriform) syndrome. Upper left: initial ulcerative lesion (sporotrichotic chancre) at point of original percutaneous inoculation. Lower left and upper right: ulceronodular lesions along lymphatic channels of arm. Middle right: chancre and first of chain of lymphatic ulceronodular lesions. Lower right: original chancre and lower part of secondary lymphatic series, showing close similarity of appearance.

PLATE

6. Sporotrichosis: primary cutaneous (chancriform) syndrome. Upper left: initial lesion and first of secondary lymphatic chain. Middle and lower left and upper right: facial lesions in children. Middle right: lymphatic chain of large secondary lesions not yet ulcerative. Lower right: verrucous appearance of primary lesion, gradually spreading peripherally in skin. PLATE

P L A T E 7. Sporotrichosis: verrucous and aberrant types. Upper left: primary cutaneous chancre on dorsum of foot, with verrucous peripheral extension. Middle left: verrucous form, spreading peripherally in skin. Lower left: superficially ulcerative lesion spreading peripherally in skin. Upper right: multiple verrucous lesions on ankle. Lower right: histopathologic picture of human tissue in disseminated sporotrichosis, showing fungal cells in giant cell (PAS x 900).

8. Sporotrichosis: histopathology and appearance in culture. Upper left: tissue section in disseminated sporotrichosis, showing Sporotrichum schenckii in giant cell (H & E x 600). Middle and lower left: same as above (PAS X900). Upper right: asteroid form, occasionally seen in sporotrichosis when well resisted. Middle right: variations in color of different strains of S. schenckii growing on carrot medium. Lower right: S. schenckii, gross appearance of colony on Sabouraud's medium. PLATE

Plate 9. Histoplasmosis: lesions of the tongue. The tongue is a common site for rare mucocutaneous form. Middle left and upper right: granulomatous ulcerative lesions on dorsum of tongue. Upper and lower left and lower right: involvement of posterolateral surface.

IO. Histoplasmosis: other mucous membrane lesions. Upper left: granulomatous ulceration of hard palate and alveolar ridge. Lower left: histoplasmosis in coronal sulcus of penis. Upper right: penile involvement of same type, but more severe. Lower right: cicatricial area remaining after spontaneous cure of primary cutaneous inoculation case (chancriform type). PLATE

PLATE II. Histoplasmosis: cutaneous lesions and histopathology. Upper left: histoplasmosis of upper lip. Middle left: granulomatous ulcerative histoplasmosis of skin of arm. Lower left: topography of cutaneous histoplasmosis ( x i o o ) . Upper right: fungus cells in their favorite location within reticuloendothelial cell (H & E x 900). Lower right: histoplasmosis in lung (PAS x i o o ) .

PLATE I 2. Histoplasmosis: histopathology and cultural characteristics. Upper and lower left: histoplasmosis in tissue (PAS x i o o and x 200). Middle left: same (H & E X400). Upper right: Histoplasma capsulatum in room-temperature culture, filamentous phase. Lower right: typical tuberculated conidia of H. capsulatum (PAS x 900).

Sporotrichosis

55

all) in tissue sections or exudates by the usual staining procedures, even with the periodic acid-Schiff staining procedure. A n d yet the organisms are easily defined in tissues from experimentally infected animals and in those from human beings possessing the disseminated type. This feature has recently been clarified by Fetter, who has succeeded in demonstrating the organisms in most specimens by a special technique, in which all nonfungal polysaccharide is first dissolved away by an enzyme (originally salivary ptyalin but later a 1:1,000 solution of malt diastase), and then PAS or a methenamine-silver impregnation method is used for staining. Kaplan and Gonzalez-Ochoa have shown that Sporotrichum schenckii is easily demonstrated in exudates from lesions by using rabbit antiglobulin specific for that fungus, which has been labeled with fluorescein isothiocyanate. Living and dead fungal cells are seen as brightly fluorescent bodies against a dark background. T h e organisms are usually described as tiny, cigar-shaped bodies, 3 to 5 microns in length, which bear from one to three small oval buds at either or both poles; spherical bodies varying in size up to 8 microns also occur. Occasionally a larger asteroid form may be seen. T h e organisms are probably present in large numbers immediately after the inoculation, but are soon diluted and decreased in quantity by the strong defense mechanisms of the host. Lesions in the skin show hyperkeratosis, parakeratosis, and pseudoepitheliomatous hyperplasia, with intraepidermal microabscesses. There are foreign-body giant cells in the dermis, with lymphocytes and plasma cells, and an occasional Russell body. A sporotrichotic nodule usually shows several more or less concentric zones, the central one composed of an anuclear mass of necrotic material, sometimes purulent, surrounded by polymorphonuclear leucocytes, merging into a zone of fibroblasts, lymphocytes, epithelioid cells, and giant cells. Except for this tendency to concentric zones, the granulomatous picture cannot be differentiated from that in syphilis, tuberculosis, or other deep mycoses. In the center there is often one of the so-called asteroid bodies (first described by Splendore in 1908), which are central spherical fungal cells, occasionally budding, surrounded by a stellate or raylike arrangement of projections in a rather irregular pattern. T h i s material is eosinophilic and homogenous, and the length of the rays may increase the total diameter up to 25 microns. In 1932 Weidman suggested that the substance surrounding the cell in the asteroid body was produced by the fungus. Moore has suggested several theories; one of them, that the substance is a product of the host-parasite relationship, is currently the most popular. He points out that asteroid forms have been observed in practically all other deep fungous diseases. Lurie (1963a) has recently classed the asteroid material as a glycoprotein resulting from an antigen-antibody reaction which OCCUFS when host resistance is high. There have been a few reports that hyphae were seen in sporotrichotic nodules.

56

T h e systemic mycoses

Fortunately, in view of the difficulty of establishing the diagnosis by histopathologic examination, cultural methods are usually successful in demonstrating the presence of Sporotrichum schenckii in any stage of the disease. T h e fungus is easily isolated in culture, grows well, and is readily identified. DIFFERENTIAL

DIAGNOSIS

T h e usual chancriform-lymphoglandular type of sporotrichosis presents so classical a picture that it is frequently diagnosed with great accuracy from its clinical appearance alone, especially when there is a history of injury from vegetation or wood. It must be differentiated from syphilis, tularemia, anthrax, glanders, and furunculosis, and from the primary cutaneous (chancriform) complexes of tuberculosis, coccidioidomycosis, North American blastomycosis, histoplasmosis, and American leishmaniasis. T h e verrucous form may easily be confused with the similar stage of blastomycosis, chromoblastomycosis, coccidioidomycosis, or tuberculosis, and the disseminated type, with many other internal disorders, principally syphilis, tuberculosis, other deep mycoses, and neoplasms. Laboratory studies are needed for such differentiation, the easiest of which is culture on artificial media. MYCOLOGY Sporotrichum schenckii (Matruchot, 1910) is dimorphic, growing on all artificial media at room temperature as a moist or fluffy mycelial mat, and at incubator temperature, as well as in the tissues of animals or man, almost exclusively as a yeastlike budding organism. O n artificial media it begins as a moist, adherent creamy-white mass, but in most strains it soon begins to turn brown in varying degrees, then almost black, and the surface becomes highly wrinkled, sometimes with white fluffy areas of pleomorphism. Microscopically, branching septate filaments are seen, which in contrast with most other pathogenic fungi are very slender, varying from 1 to 2 microns in diameter. Continuous awareness of the degree of magnification being employed at the instant is never more obviously valuable than it is in this instance. Short conidiophores, which bear at their extremities grapelike clusters of conidia, develop at right angles from these hyphae; the conidia are oval, rounded, or pear-shaped, from 2 to 5 microns in length. Some of them may produce one or more buds at their tips, usually only after separation from the conidiophore. Later, similar conidia are formed along the sides of the conidiophores, and even from the hyphae themselves. Close observation reveals a very helpful, differential feature of these conidia: at first glance they all appear to be separated from the bearing structure by a short but constant distance,

Sporotrichosis

57

which is shown by careful focusing under oil immersion to be caused by a very fine hairlike stalk called a sterigma, characteristic for the genus Sporotrichum (trich = hair). Brown, Weintraub, and Simpson have described triangular spores with edges 2 to 5 microns in length and with convex surfaces that cause them to appear oval on cross section; this shape is seen in culture colonies as well as when the fungus was growing on wood. When searching for the fungus in nature they found the presence of this type of spores to be a helpful clue. In cultures held at incubator temperature, reproduction occurs almost exclusively by a budding process. Oval, cigar-shaped, or elongated yeastlike cells up to 5 or more microns in length are rapidly and continuously produced by buds formed at either extremity, singly or in groups of two or three. Cells that are spherical and much larger are usually the nonbudding forms seen more frequently in African varieties of the fungus. Animal inoculation intraperitoneally is helpful at times, and mice or rats serve well. Smears from the nodular peritonitis that develops reveal the yeastlike forms described above. IMMUNOLOGY

It is amply evident that the normal human body strongly resists the intracutaneous inoculation of 5. schenckii, for it produces an intense cellular response both locally and throughout the adjacent lymphatic structures, sufficiently effective to prevent the spread of the infection beyond the inoculated limb; usually, however, the response is not strong enough to achieve complete, spontaneous cure. That this resistance is not owing to a naturally present potential, but is developed immunologically as the result of the stimulus supplied by the infection, is obvious from the fact that organisms are present and multiplying rapidly just after the inoculation, but begin to be reduced in number coincident with the onset of the inflammatory reaction of the host. Experience with other microbial diseases suggests that this process should be accompanied by other observable immuno-allergic phenomena, as indeed it is. Beginning in 1908 with the work of Widal and Abrami and of Bloch, extracts derived from cultures of S. schenckii, termed sporotrichins, have been employed in testing procedures. Most of the reports emphasized that the results fell short of the goal to be expected of an ideal antigen, citing examples of "false positive" and "false negative" reactions, so termed because in many instances they seemed to the observers not to follow consistently the clinical status of the patients. By those who believe that the power to resist a fungal disease by an acquired immunologic mechanism is paralleled to a reasonable degree by the ability to react to the intracutaneous test with extracts of the causative fungus, it is to be expected that high skin-test reactivity to sporotrichin will also be the rule

58

The systemic mycoses

in primary cutaneous sporotrichosis. And, in fact, it is the rule, de Beurmann being the first of many observers to accept a negative skin test as sufficient evidence to rule out present or past sporotrichosis. This reaction is probably reliable in all but the earliest stages of the disease, and the late stages of disseminated or fatal disease, when the host may become anergic. In infections experimentally produced in a volunteer it has been observed that the skin test became positive as early as the fifth day following the inoculation. The so-called immediate flare reaction has been observed, but cannot be correlated with the presence or the absence of the disease, or with its clinical course. It is the delayed tuberculin type of response which is useful, as emphasized by Gonzalez-Ochoa. De Beurmann occasionally observed allergic cutaneous reactions (sporotrichids) in hypersensitive individuals, analagous to the coccidioidids described above, although much less marked in degree. Long ago de Beurmann reported false positive reactors to sporotrichin testing, that is, persons who had no history suggestive of sporotrichosis but yet showed positive reactions. It is important to recall that, in coccidioidomycosis, reactions to intracutaneous testing with coccidioidin of the type previously considered to be false positives are in reality true positives, for they occur almost exclusively in persons who have actually had the disease and recovered, even though it may never have been clinically perceptible. It appears at least plausible that the same phenomenon may account for false positive reactors to sporotrichin, that is, that many of, if not all, the persons showing such reactions have previously had the disease. Helm and Berman have observed cases of sporotrichosis of a mild, superficial type which healed spontaneously, but the patients' reactivity to sporotrichin was not mentioned. In mild cases such as these the diagnosis of sporotrichosis might very easily have been missed, and thereafter a person so affected might react positively to the sporotrichin skin test and be classed incorrectly as a false positive reactor. These investigators were also unable to produce sporotrichosis in some persons by experimental injection of the organisms, indicating the presence of immunity; they do not state whether or not these persons were tested with sporotrichin, but it might be that they would have reacted positively, indicating that the immunity was of the specific acquired type rather than natural. Padilha-Gon$alves, speaking for the Brazilian Cooperative Group, reported the results of a survey of skin-test reactivity in groups of persons residing in the vicinity of regions where cases of sporotrichosis frequently occurred. Of persons working in a dermatologic clinic in an endemic area, 57 percent were skin-test positive; of adults in the same region not working in the clinic, 27 percent reacted; of the children in that area, 10 percent were reactors, but of children who had been isolated early in a leprosy preventorium, only 6 percent reacted. No reactors were discovered in Portugal, where sporotrichosis has not been reported to occur. Gonzalez-Ochoa has recently prepared a purified polysaccharide

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59

from Sporotrichum schenckii which he believes to be more highly specific, particularly by avoiding false positive reactions to extraneous proteinlike substances. Apparently patients who have had sporotrichosis in the severe disseminated form leading to death have not been adequately tested with sporotrichin. Experience with coccidioidin suggests that such persons would react poorly, if at all, to the intracutaneous test, at least for a varying period before death, thereby furnishing examples conflicting with the opinion that a negative reaction rules out sporotrichosis. In the series of cases reported by Gonzdlez-Ochoa, one patient who had sporotrichosis generalized through the bloodstream failed to react to the skin test. Padilha-Gon^alves stated that this reaction may be negative in disseminated disease. T h e complement-fixation test T h e complement-fixation test has yielded variable results in the hands of different investigators. Norden (1951) found it to be positive in only two of his eleven cases, the titer not being specified. T h i s is not surprising if this reaction adheres to the pattern that seems to have been established in coccidioidomycosis (and probably in both the blastomycoses and histoplasmosis as well), in which the complement-fixation titer parallels the total quantity of involved tissue (or, in a later view, the total number of organisms actively engaged in producing the disease) at the time the test is made. In the ordinary type of chancriform sporotrichosis, except in the very early stages, the organisms are so sparse in the tissues as to be undiscoverable by histopathologic study; we would expect so small a number of organisms to produce little or no complement-fixing reactivity. Gonzalez-Ochoa could not obtain complement fixation with his purified polysaccharide material, perhaps because some necessary protein-like component had been removed in purifying the polysaccharide by repeated precipitation with 96 percent alcohol. It appears likely that the ability of an antigen to participate in the complement-fixation reaction depends upon its possessing protein or protein-like elements, which may easily be destroyed or lost by many purifying or sterilization procedures. Before it is concluded that a complement-fixation reaction cannot be developed into a reliable, consistent testing procedure in any disease, attempts should be made to produce antigens that have not been denatured so as to degrade or injure any protein-like components that might be present. By his precipitation test, Gonzalez-Ochoa found that two of his patients were strongly positive, two were less strongly positive, three were doubtfully positive, and two were negative. One of the strongly positive serums came from a patient who failed to react to the skin test. Padilha-Gongalves could find no differences in reactions to antigens produced from the yeast-form or mycelial phases of cultures. According to Padilha-Gon^alves, the serologic agglutination test is posi-

60

T h e systemic mycoses

tive in both the localized and disseminated forms of the disease, and the precipitin and complement-fixation tests are positive in some cases and negative in others. T h e data thus far available do not support any correlation between these tests and the clinical course, or any other features, of the disease. Apparently these tests may remain positive long after cure. It is evident that much additional data must be assembled before these tests can be adequately evaluated. One pitfall that must be avoided is the anticipation of the same results from all these tests (i.e., all tests negative or all tests positive) in a given patient at a given time. T h e y do not so parallel each other in coccidioidomycosis or other deep mycoses; indeed, it is evident that each test reveals the presence of a different antibody and that each is of different significance for the diagnosis of the disease as well as for the prognosis of the patient. It seems likely that similar conditions prevail in sporotrichosis. THERAPY Potassium iodide was discovered long ago to be practically a specific curative for sporotrichosis, failing only in widely disseminated cases and in a few instances because of the patients' intolerance to its continued administration. A t present it is still the drug of choice, and the consensus is that it will be difficult for any drug to dislodge it. T h e time-honored method of administration, using the saturated aqueous solution in the form of drops in half a glass of water or milk, is still popular, usually beginning with 15 drops three times a day, and increasing the dosage to at least 30 and often to 40, as tolerated. Some clinicians begin with smaller doses, and increase each dose by 1 drop until the maximum is reached. If well tolerated, the drug should be continued for four to six weeks after the last clinical sign of the presence of disease has disappeared. If gastric irritation interferes, sodium iodide administered intravenously is efficient. T h e manner in which iodide exerts its beneficial action is still not clear. T h e concentration of iodide induced in the body tissues in general by the usual mode of administration probably cannot exceed 1:8,000, whereas it is known that Sporotrichum schenckii can be grown in culture in a medium containing up to 10 percent iodide (Gonzalez-Ochoa). Using radioactive iodine (1:131) as a tracer, Shintani and Wilson could not demonstrate any localized uptake by any of the cells of the host in sporotrichotic lesions in animals, nor any concentration in the areas of the lesions in general. Nevertheless, iodide therapy practically never fails in the ordinary chancriform type of sporotrichosis. It is much less reliable in the disseminated form, suggesting that the high degree of immunologic resistance exerted by the patient who possesses the chancriform type is of the greatest importance, and that the iodide may simply augment the resistance element in some small but vitally necessary way. T h i s would

Sporotrichosis

61

explain its failure in disseminated sporotrichosis where the resistance may be entirely absent, or where an inherent defect in the patient's immunologic processes may be operative. At present the data are insufficient to permit examination of the value of iodide therapy in the light of the prognostic studies yielded by the interplay between the skin-test and complement-fixation titers, as has been recommended in coccidioidomycosis. It will be extremely interesting to watch for such reports. Soon after its discovery, griseofulvin was reported to be helpful in sporotrichosis, but the initial enthusiasm has waned. It is admittedly slower, less reliable, and more expensive than potassium iodide, but it may be worthy of trial in patients who are shown to be resistant to or intolerant of the latter. Amphotericin B, though apparently very effective in sporotrichosis, has not yet been subjected to extensive trial because it is more expensive and more toxic than potassium iodide, and because hospitalization with costly laboratory testing is needed for its intravenous administration. It is good to know, however, that there is an alternative to iodide therapy, especially for the more resistant disseminated form so dangerous to life. Surgery is contraindicated because it apparently breaks the patient's wall of resistance, and is often followed by spread of the infection. It is even recommended, for the same reason, that fluctuant accumulations of pus be treated by aspiration rather than by incision and drainage. For resolving granulation tissue, moderately filtered X-radiation is helpful. When progress is slow, vaccines prepared from the yeastlike phase of S. schenckii have been recommended as supplements to iodide therapy. The status of such preparations is questionable, as in the other deep mycoses, particularly because vaccine therapy has not yet been proved capable of curing cases of the disseminated variety. Padilha-Gon^alves, believing that sporotrichin injections have been curative in many cases, recommends their use, especially in cases resistant to or intolerant of iodide therapy. Apparently he prefers not to include it among other therapeutic measures, but to allow it to stand alone if selected. He admits, however, that the results may be owing to the development of specific immunologic resistance by the host in response to the disease itself, rather than to the vaccine. MacKinnon and Corti-Diaz have found that Sporotrichum schenckii does not grow well above 38°C (as is true also of some other pathogens). They recommend that the affected limb be treated with massive compresses heated to the point of tolerance. They have reported one case that seemed to be helped by this procedure. As with other deep mycoses, the usual antibiotics which are effective against bacteria should be withheld, unless they are specifically indicated because of concomitant obvious secondary infection with susceptible bacteria. None has yet been shown to exert any inhibitory action against

62 Sporotrichum

The systemic mycoses schenckii;

in fact, González-Ochoa a n d Soto-Pacheco have

shown t h a t penicillin p r o m o t e s its growth, a n d C a m p b e l l a n d Saslaw attributed the same type of activity to streptomycin. W i d e - s p e c t r u m antibiotics, by interfering with bacterial assistance in digestive processes, m a y also deprive the body of p r o t e i n elements valuable in developing antibodies. Some necessary v i t a m i n B factors m a y be similarly inhibited.

Bibliography Belliboni, N. i960. Esporotricose: contribucáo para o estudo epidemiológico, clínico, histopatológico e terapéutico. Unpublished thesis. Sao Paulo. P. 121. Benham, R . W., and B. Kesten. 1932. Sporotrichosis: its transmission to plants and animals. J. Infect. Diseases, 50:437. Carr, R . D., M. A. Storkan, J. W . Wilson, and F. E. Swatek. 1964. Extensive verrucous sporotrichosis of long duration. Arch. Dermatol., 89:124. Crevasse, L., and P. D. Ellner. ig6o. A n outbreak of sporotrichosis in Florida. J. Amer. Med. Assoc., 173:29. Garrett, H. A., and J. B. Robbins. i960. A n unusual occurrence of sporotrichosis: eight cases in one residence. Arch. Dermatol., 82:570. Hayes, W . N. i960. Sporotrichosis in employees of a tree nursery. Gen. Practice, 22:114. Howard, D. H. 1962. T h e morphogenesis of the parasitic forms of dimorphic fungi. Mycopathologia, 18:127. Kaplan, W., and A. González-Ochoa. 1963. Rapid diagnosis of sporotrichosis. J. Lab. Clin. Med., 62:835. Latapí, F., P. Lavalle, J. Novales, and Y. Ortiz. 1959. Griseofulvina en micosis cutáneas y profundas: nota preliminar sobre resultados terapéuticos en un caso de micetoma por N. brasiliensis y en una de esporotricosis por S. schenckii. Dermatol. Rev. Mexicana, 3:34. Lavalle, P. i960. Esporotricosis: tratamiento con griseofulvina y cortico-esteroides. Congr. 35th Anniversary Asoc. Méd. Panamer., Mexico, May 2-11. Lowenthal, L. J. A. 1959. Sporotrichosis treated with griseofulvin. Med. Proc. (S. Africa), 5:563. Londero, A. T . , O. Fishman, and C. D. Ramos. 1963. Sporotrichosis in R i o Grande do Sul. [In Portuguese.] Hospital (Rio.), 63:1441. Lurie, H. I. 1948. A common antigenic factor in different species of Sporotrichum. Mycologia, 40:106. . 1963a. Histopathology of sporotrichosis: notes on the nature of the asteroid body. Arch. Pathol., 75:421. . 19636. Five unusual cases of sporotrichosis from South Africa, showing lesions in muscles, bones and viscera. Brit. J. Surg., 50:585. Lynch, A. C., et al. 1963. Systemic sporotrichosis with bilateral synovitis in the knees. Proc. Mayo Clin., 38:358. Moore, M., and R. L. Kile. 1935. Gerealized subcutaneous, gummatous, ulcerating sporotrichosis. Arch. Dermatol. Syphil., 31:672. Newcomer, V. D., and R . S. Homer, i960. Localized lymphatic sporotrichosis treated with oral amphotericin A and B. Arch. Dermatol., 81:472.

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Norden, A. 1951. Sporotrichosis: clinical and laboratory features, and a serologic study in experimental animals and humans. Acta Pathol. Microbiol. Scand., Suppl. 89. Padilha-Gon^alves, A. i960. Tratamento da esporotricose pela esporotriquina. Sess. Soc. Brasil. Dermatol, Sifilograf., Oct. 26. Pereira, A. M., A. Padilha-Gon^alves, C. da S. Lacaz, C. Fava-Netto, and R. Martins de Castro. 1962a. Immunology of sporotrichosis. I. The sporotrichin test after recovery from sporotrichosis. [In Portuguese.] Rev. Inst. .Med. Trop. (Säo Paulo), 4:383. . 19626. Immunology of sporotrichosis. II. The sporotrichin test in children without sporotrichosis. [In Portuguese.] Rev. Inst. Med Trop. (Säo Paulo), 4:386. Pijper, A., and B. D. Pullinger. 1927. An outbreak of sporotrichosis among South African miners. Lancet, 2:914. Pinkus, H., and J . N. Grekin. 1950. Sporotrichosis with asteroid tissue forms. Arch. Dermatol. Syphil., 61:813. Ramos e Silva, J . 1963. Sporotrichosis in Brazil. [In French.] Laval Med., 34:739. Schenck, B. R . 1898. On refractory subcutaneous abscesses caused by a fungus possibly related to the sporotricha. Bull. Johns Hopkins Hosp., 9:286. Silva, M. F., H. Neves, A. M. Pereira, A. Padilha-Gon^alves, C. da S. Lacaz, C. Fava-Netto, and R. Martins de Castro. 1963. Immunology of sporotrichosis. III. The sporotrichin test in persons without sporotrichosis in Portugal. [In Portuguese.] Rev. Inst. Med. Trop. (Sao Paulo), 5:12. Sporotrichosis infection in mines of the Witwatersrand: a symposium. 1947. Proc. Transvaal Mine Med. Officers' Assoc., Johannesburg. Torrico, R. A., and C. Romana. 1959. Caso de cura espontánea de una infección esporotricósica. Ann. Inst. Med. Regional, 5:59.

6 Histoplasmosis

INTRODUCTION DURING T H E PAST twenty years, by reason of increasing medical knowledge, histoplasmosis has been catapulted from its former position as an extremely rare disease to a place among the most common. It exhibits a wide range of clinical forms, varying through many stages of severity from one that is entirely asymptomatic to one that pursues a rapid course to death. The causative organism is unique among pathogenic fungi in exhibiting a strong preference to live only intracellularly in animal tissues, usually in cells of the reticuloendothelial system. Nevertheless, there are close resemblances between the clinical features of this disease and those of many other infections, notably coccidioidomycosis and tuberculosis.

HISTORY Histoplasmosis was discovered in Panama in 1906 by Darling while he was searching for Leishman-Donovan bodies in necropsy material from 64

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a person whose lungs, spleen, liver, and lymph nodes grossly revealed pseudotubercles and focal necroses. He saw the tiny (3 to 5 microns) round or oval bodies surrounded by refractive capsules and realized that they were different from Leishmania, but nevertheless apparently accepted their protozoan nature. H e named the organism Histoplasma capsulata, and this designation persists today except for the correction of the species epithet to capsulatum for language reasons. Darling reported two similar cases in igo8 and 1909. N o other cases were discovered until 1925, when Riehl reported one from Austria, followed the next year by cases observed in Central America, the Philippines, and the United States (Minnesota), and still later in the Dutch East Indies. A l l the authors who reported these cases were doubtful about the nature of the organism, although as early as 1912 da Rocha-Lima suggested that it might be a fungus. Working independently, de Monbreun (1934), almost simultaneously with Hansmann and Schencken (1934), succeeded in culturing the organism and establishing its identity as a fungus; they described its characteristics and made it easier to establish the diagnosis. Thereafter cases were discovered with increasing frequency, and in 1945 Parsons and Zarafonetis were able to list seventy-one of them. In all these cases the disease was extremely severe, and only in a very few instances was the diagnosis made before the patient died. U p to 1945 the history of histoplasmosis closely paralleled that of coccidioidomycosis, before Gifford and Dickson discovered that the latter exists in a widespread benign form. T h e impetus to investigate the possibility of a similar phenomenon for histoplasmosis arose from the desire to explain the presence of pulmonary calcification in numerous persons who could not be shown to have had tuberculosis. Nontuberculous pulmonary calcifications in California had been successfully attributed to coccidioidomycosis in some persons, in spite of the fact that the disease had been otherwise inapparent to them throughout its course. Accordingly, a number of persons who had resided in Midwestern United States and had pulmonary calcifications were tested with coccidioidin; many were found to react positively, but only when strong concentrations of the antigen were employed. Still, the percentage that did so react was found by Nelson and Furcolow to be significantly higher among those who revealed pulmonary calcifications than among those who did not, yet none of these people could be shown to have had coccidioidomycosis. C. E. Smith suggested that this finding might best be explained on the basis of cross reactivity, because of a common antigen of lessened potentiality possessed by two different fungi, the second of which was actually the cause of the disease in question. Arguing from the significant degree of localization of fatal cases of histoplasmosis in certain geographic areas where the percentage of pulmonary calcification was also high, Smith suggested that the pathogenic organism might be Histoplasma capsulatum. Testing then

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T h e systemic mycoses

began with extracts of this fungus, called histoplasmin, and revealed excellent positive responses, indicating that this view is correct. After a great deal of study by Christie and Peterson, Palmer, Prior and Allen, and others, the evidence not only indicated that it was quite plausible to attribute the pulmonary calcification to histoplasmosis, but also revealed that within certain geographic areas a very large percentage of individuals who had no such lesions, and in fact showed no history even remotely suggestive of histoplasmosis, nevertheless reacted strongly to the histoplasmin test. Observers then began to suspect that histoplasmosis exits in a benign form which is acquired by huge numbers of persons who never exhibit any symptoms or signs. T h i s occurrence is, of course, the exact counterpart of coccidioidomycosis, as we now understand it. Additional confirmatory evidence in recent years has practically proved the theory. In 1949 Emmons demonstrated the existence of H. capsulatum in soil, and his finding has since been confirmed by many others. More recently, the association of this fungus with excreta of poultry, starlings, pigeons, grackles, and bats has answered many questions concerning epidemiology. ETIOLOGY Histoplasmosis is caused by Histoplasma capsulatum, a dimorphic fungus which exhibits a strong preference for reticuloendothelial cell parasitism when in animal tissues. Some authorities designate a form encountered in Africa as a separate species, H. duboisii. DISTRIBUTION Histoplasmosis occurs most frequently in North America, particularly in the north central part of the United States, along the Mississippi River and its larger tributaries, the Missouri, the Ohio, and the Tennessee, and in the states along the eastern seaboard. Significant numbers of cases have also been discovered in many other regions of the world, especially in Central and South America, Indonesia and other Pacific islands, Australia, South Africa, and Europe. N o age group is exempt, but infants, children, and elderly persons are particularly susceptible to the serious forms of the disease. Like so many other fungous diseases, histoplasmosis more commonly affects males and persons whose work necessitates intimate contact with the soil than other groups. EPIDEMIOLOGY Histoplasmosis has never been shown to have been transmitted from man to man or from animals to man. T h e source of infection is the soil, almost invariably by inhalation of light, airborne spores into the lungs along

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with terrestrial dust. The larger the quantity of spores inhaled, the more severe seems to be the disease. On the first few occasions when the fungus was isolated, it was in close relationship with excreta from chickens, but soon other birds, as well as bats, were similarly implicated. Cats, dogs, rats, mice, skunks, ferrets, cattle, and horses have been shown to be infected, although they do not succumb or appear to have the disease. These animals, as well as humans, are known to excrete the fungus in sputum, urine, and feces. It is not freshly passed excreta, however, which harbor the fungus in the infectious form, but manure mixed with soil and decayed litter from chicken houses, especially if it has lain undisturbed for months (as described in a revealing set of cases by Loosli). Persons entering caves inhabited by birds, and especially by bats, have become infected with histoplasmosis in Mexico, the United States, Venezuela, Peru, Colombia, and South Africa. Bats live in large colonies in attics of old buildings, and cause fecal contamination of the soil near the foundations. Histoplasma also grows in soil beneath trees sheltering starlings and other birds, and such foci are important sources of infection in cities. T h e first such isolation by Emmons (1961) was actually in a shopping area in Washington, D.C. T o lessen the chance of infection, Emmons and Piggott recommend placing several inches of clay or shale soil on top of the ground in areas close to human dwellings which have been shown to be infected. This preventive measure is better than the use of chemicals or oil, which may destroy all vegetation. The usual portal of entry is the respiratory tract. Although the gastrointestinal system is also commonly involved in human histoplasmosis, it is not certain that the fungus can actually cause infection by that route, though animals have been experimentally so infected. It is likely that the frequency of oral lesions, especially in children, may be related to soil being brought to the mouth on fingers or food. All such lesions may of course arise by dissemination from primary pulmonary foci. Percutaneous inoculation must occur only very rarely, although it has been shown that animals can be infected by such injections, and there are at least two convincing records of human infection via that route. CLINICAL

CHARACTERISTICS

Although the existence of the following syndromes as separate clinical entities cannot be regarded as definitely established, it seems likely that eventually they will be so established. It is therefore pertinent to discuss the disease under these headings. Primary pulmonary histoplasmosis There is no incontrovertible evidence that cases of histoplasmosis observed to be limited to the lungs constitute a separate clinical entity. Nevertheless, such a grouping, which is virtually certain to be deemed

Fig. 4. Histoplasmosis: pulmonary calcifications. Rounded calcifications, fairly uniform in size, rather evenly distributed throughout both lungs; calcifications in mediastinal and hilar lymph nodes.

valid, would probably include all cases that remain subclinical and asymptomatic throughout the entire course of the disease and clear quickly, leaving as sequelae only the ability to react positively to the skin test and, in some cases, to exhibit pulmonary or splenic calcification shadows by X-ray examination. It should also probably include the early phase of most cases of histoplasmosis in which the disease was shown to be present first in the lungs, even though it later spread by hematogenous dissemination to other organs. Bunnell and Furcolow observed a proved case in which the disease remained limited to the lungs until the patient recovered, and Christie has reported other cases apparently limited to the respiratory system. Schulz found the lungs to be the most frequently affected organ in persons above the age of five; in younger persons the disease favored the liver or the lymph nodes. In a convincing study, Straub and Schwarz found evidence of past or present histoplasmosis in the lungs

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of 67 percent of 105 persons dying of other causes within an endemic geographic area. Hodgson, Weed, and Clagett have described the symptomatology of pulmonary histoplasmosis, as well as of other forms of the disease. Coughing, with or without sputum, is common; chest pain is frequent; fever is the rule; hemoptysis is rare. Dyspnea and noctidrosis may occur. Atelectasis, emphysema, cavitation, or pleurisy with effusion are sometimes present, with their typical symptoms. Ulcerated lesions of the larynx have been described, with hoarseness as the presenting symptom. Schulz has described the primary pulmonary complex of histoplasmosis as being pathologically similar in many respects to that of tuberculosis in size, shape, and location. Usually it is a small, circumscribed subpleural lesion, generally caseated and frequently located in the lower two-thirds of the lobes. The regional lymph nodes are hyperplastic, but are less likely to be caseous than in tuberculosis. There are no diagnostic radiographic features by which histoplasmosis may be differentiated from other pulmonary inflammatory diseases, and the picture varies extensively. Primary complexes have been shown at autopsy which were not revealed by chest films taken only the day before death. The incubation period as established by study of epidemics is said to be from five to fifteen days. Primary cutaneous histoplasmosis According to reports beginning in 1952, if coccidioidomycosis and blastomycosis are acquired by direct inoculation of the causative fungi into the skin of a previously uninfected person, the resulting syndrome is a highly characteristic chancriform primary cutaneous complex, rather than an abscess or single or multiple chronic, spreading skin lesions. Curtis and Harrell have observed a case of histoplasmosis apparently of the same type. Their patient exhibited an ulcerative lesion on the penis, accompanied by regional lymphadenopathy; he became well spontaneously, and suffered no recurrence. More recently, Tosh and Furcolow have reported another similar case, closely resembling the usual form of sporotrichosis, consisting of an indolent ulcerative primary lesion accompanied by lymphangitis and lymphadenopathy in the region of drainage. Again the patient recovered spontaneously. The extreme rarity of this syndrome need not argue against its existence, for H. capsulatum resembles Coccidioides in its cultural phase in nature more closely than it does Sporotrichum, growing in soil rather than on vegetation possessing thorns or splinters capable of penetrating the skin, and hence is probably not often inoculated percutaneously. In numerous recorded instances, of course, the first evidence of histoplasmosis was a lesion or lesions in the skin or mucous membranes, but

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there is no conclusive proof that these sites were actually the portal of entry. Frequently the lesions have been identical in morphology and subsequent course with those observed in other individuals in whom they were known to have occurred by hematogenous dissemination of the organisms. Histoplasmosis has been produced by direct inoculation of the organisms into the mucous membranes or the skin of animals, and a similar route of infection in human beings must be considered possible. If and when the question of intracutaneous inoculation arises, students of histoplasmosis would do well to apply the criteria outlined for primary cutaneous coccidioidomycosis (see chap. 4). There is not sufficient evidence at this time to permit further discussion of this phase here, except to point out that extrapulmonary lesions almost certainly signal the presence of disseminated disease with serious prognosis, rather than a benign primary cutaneous form. Disseminated histoplasmosis T h e use of the term "disseminated" for the long-known type of histoplasmosis which involves many parts of the body is subject to some criticism, as it implies that there is conclusive proof of the existence of a preceding primary form of the infection. T h e trend of advancing knowledge, however, is ever more strongly in this direction, and it seems likely that this concept will soon become firmly established. It is therefore postulated that a very small percentage of the vast number of persons who acquire the primary pulmonary form of histoplasmosis fail to resist it in the usual efficient manner, that the lungs become more extensively involved, and that finally the fungus cells enter the bloodstream and are carried throughout the body to lodge in the capillary beds. Lesions that have proved to be histoplasmosis have been reported in all organs of the body except the cortex of bone and cartilage, but, as all tissues are not equally susceptible, the resulting disease picture may show considerable variation. There is reason to believe that some individuals, even after dissemination, resist the disease sufficiently to keep it entirely asymptomatic while they are achieving a natural cure, for areas of calcification, similar to those so well known in the lungs, are sometimes found by roentgenography in other organs, especially the spleen, in otherwise normal individuals residing in endemic areas (Straub and Schwarz). Also, as noted above, a high percentage of persons dying from entirely unrelated causes, and revealing no history suggesting histoplasmosis, have nevertheless been shown at autopsy to have harbored the infection (Christie, 1958; Straub and Schwarz, 1950). T h e majority of patients with proved disseminated histoplasmosis, however, become seriously ill, and most of them die, although sometimes not for several years. H. capsulatum shows a pronounced predilection for invading all types

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of cells belonging to or derived from the reticuloendothelial system, possibly in some instances because of an earlier disease of this system. It has been established, at least, that histoplasmosis is coexistent with such reticuloendothelioses as leukemia, Hodgkin's disease, lymphosarcoma, and sarcoidosis much more frequently than is statistically justifiable on the basis of coincidence. Radaelli and Ciferri have shown that elements of the fungus which are introduced into animals are phagocytized at once by monocytes and macrophages, in which they do not die but multiply and are subsequently borne hematogenously or by way of the lymphatics to organs rich in reticuloendothelial elements, such as lymph nodes, spleen, liver, and bone marrow. This pronounced predilection for a certain type of cell largely determines the clinical picture in the typical case, although the disease often spreads beyond any such confines and may bring a wide variety of signs and symptoms. T h e disease progresses at variable rates. T h e usual syndrome is marked by subacute to chronic wasting, irregularly febrile disease, accompanied usually by anemia, leucopenia, generalized lymphadenopathy, and enlargement of spleen and liver. The common symptoms are nausea, vomiting, anorexia, diarrhea, and gastrointestinal pain. Pleurisy, pulmonary infiltration, and tracheobronchitis occur frequently; endocarditis and involvement of the adrenals or of the central nervous system are reported occasionally. Lesions of the mucous membranes are common, especially of the mouth, tongue, and genitalia, usually in the form of torpid ulcers or granulomatous masses accompanied by induration. Similar lesions may occur in the skin, where purpuric or even bullous eruptions are occasionally observed. Adults frequently exhibit severe pulmonary involvement, with cavitation closely resembling tuberculosis, both radiologically and symptomatically. This form of histoplasmosis is actually disseminated disease, and evidence of involvement is usually discoverable elsewhere in the body or will appear later. African histoplasmosis Some thirty cases, caused by a much larger fungus than H. capsulatum, have been reported from Africa. Named Histoplasma duboisii by van Breuseghem, it differs clinically from H. capsulatum in producing more ulcerative skin lesions and sometimes eroding into bone. Even more pronounced differences are noticeable in microscopic examination of affected tissues (see following section). PATHOLOGY Primary pulmonary histoplasmosis has not been adequately studied from the pathological viewpoint because of the mild nature of the disorder

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The systemic mycoses

and the consequent rarity of postmortem material. (See section on clinical characteristics for discussion of this form of the disease.) Disseminated histoplasmosis, however, has been very well delineated. The essential lesion is a granulomatous nodule which tends to ulcerate. The lungs almost always reveal miliary tubercules, consolidations resembling tuberculosis, and hilar lymphadenopathy. Bone marrow is almost always involved. The spleen and the liver are enlarged and hyperemic, and show tubercles and necrotic areas. The adrenals may be affected, and, less frequently, almost any other tissue of the body except cortical bone and cartilage. Histopathologically, it is strikingly evident that the fungus is seldom seen extracellularly; it is an endoparasite of cells, preferring usually those of reticuloendothelial origin. The organism is round or slightly oval, from 1 to 3 microns in diameter, and appears to be surrounded by a capsule. (Pillsbury and Kligman have demonstrated a cell wall peripheral to the capsule.) Occasional cells are seen in the process of producing a single bud. Granulomas of the pseudotuberculoid type develop around masses of parasitized cells, consisting of caseous material surrounded by a zone of granulation tissue composed of lymphocytes, plasma cells, fibroblasts, macrophages, epithelioid cells, and giant cells. Coalescence of such foci may produce large necrotic areas. The evidence of healing sometimes seen in the fibrosis lends weight to the thesis that patients with mild cases occasionally recover without the disease being recognized. Often there exists what has been termed the "solitary pulmonary nodule," or "histoplasmoma," situated usually just beneath the pleura, radiographically resembling a coin-shaped lesion. Such nodules are old lesions, often impossible to differentiate from malignancy without surgical removal for biopsy. Usually there is a caseous, calcifying center and a fibrotic wall. The fungus cells are difficult to demonstrate, requiring the periodic acid-Schiff or the Gridley stain and careful search in the central caseous material. The Gomori (methenamine-silver) stain is preferred by some authors, because the walls of fungus cells, even those long dead, are stained dark brown or black, while the calcified structures are dissolved away instead of becoming stained, as they do with other methods. In African histoplasmosis the fungi grow predominantly in giant cells, which may reach the size of 8o microns, and resemble foreign-body giant cells. In tissues the budding cells of this variety of Histoplasma resemble those of Blastomyces derm.atitid.is in size and shape, varying from 7 to 15 microns in diameter with a thick cell wall from 1.0 to 1.5 microns in thickness. They are much better stained by the PAS or the Gridley method, as the cell wall does not stain with H & E. According to Binford, granulomas composed largely of giant cells may best be seen in mesenteric lymph nodes, spleen, radius, and skull. The bone marrow may be completely replaced by the granuloma.

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MYCOLOGY Histoplasma capsulatum (Darling, 1906) is a dimorphic fungus whose natural habitat is soil, particularly soil enriched by fecal material. O n this material, as well as on artificial media at room temperature, it grows as a mat of colorless mycelium, bearing spores of two types. Small pearshaped or spherical conidia, 2 to 5 microns in diameter, are borne at right angles along the sides of hyphae or on short conidiophores which rupture to release the intact cell. As they are not abstricted from the conidiophore, they may rightly be called microaleuriospores. Sometimes the walls are spiny. Larger spores, which are often called chlamydospores but really are macroaleuriospores, are borne firmly attached to elongated conidiophores. T h e surface of these large spores (8 to 15 microns in diameter) is covered with protuberances vaguely resembling a multiple budding process, but much too irregular. T h e y are usually referred to as "tuberculated." In animal tissues, however, H. capsulatum grows only as a yeast (except very rarely in vegetations on heart valves), forming typical oval, single buds from 2 to 4 microns in diameter. ( T h e buds are larger in the African variety.) T h e neck between mother and daughter cells is usually thin and often drawn out to a thread. It was formerly believed that Histoplasma cells were surrounded by a capsule (hence its species epithet), but stains especially advantageous for demonstrating fungi, such as PAS, reveal an enclosing cell wall at the periphery. W h a t was formerly called the cell is really the nucleus, and "cytoplasm" is more appropriate than "capsule." A t incubator temperature Histoplasma grows in the same yeastlike form as in animal tissues, although some strains are difficult to maintain purely in this stage. A l l strains revert entirely to the filamentous mold stage when the temperature is lowered. In animal tissues it is easy to observe the preference of this fungus to grow intracellularly, and to see that its favorite cells are those of the reticuloendothelial system. Probably even the fungus cells not observed as intracellular were in fact developed in that location, and were then released free into the tissues by the rupture of the parasitized cells. It is often difficult to isolate Histoplasma on artificial media from animal tissues, even when it is present in large numbers. T h i s fastidiousness is also worsened by bacterial competition. It is therefore advisable to inoculate several specimens at a time, using various media, some of which contain blood, and to maintain some at room temperature and some in the incubator. In the latter, of course, fungus colonies will be in the yeastlike phase, and therefore must be carefully sought out by microscopic search to avoid being cast away as bacteria. A l l common laboratory animals are susceptible to experimental infection. Mice are usually selected, and intraperitoneal injection of only a

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The systemic mycoses

few fungus cells will reveal the infection at autopsy in two to four weeks. T h e visceral organs will be heavily invaded. DIFFERENTIAL

DIAGNOSIS

Histoplasmosis is a great imitator. Its primary acute phases must be differentiated from any severe respiratory infection, principally influenza, pneumonia, tuberculosis, or coccidioidomycosis. In the chronic and disseminated stages, histoplasmosis must be distinguished from tuberculosis, sarcoidosis, leukemia, Hodgkin's disease, blastomycosis, syphilis, leishmaniasis, actinomycosis, and chronic chest diseases of all types, including carcinoma. Such differentiation may often be difficult. T h e most accurate method is to isolate the causative fungus in culture from material obtained from lesions. This method may also be tried with sputum, gastric content, biopsy specimens, bone marrow, or blood, either directly or by the use of laboratory animals. Conversion of the intracutaneous test from negative to positive during the course of a respiratory infection is highly suggestive, and probably diagnostic in an endemic region. A positive reaction in high titer to the complement-fixation or precipitin test with histoplasmin is considered significant. Skin testing done shortly before the blood is drawn for these tests may cause them to show a false positive reaction. IMMUNOLOGY T h e estimated incidence of actual infection with histoplasmosis is in the neighborhood of 30 million, and among these cases there have been probably less than 1,000 deaths. It is at once evident that this disease offers an excellent illustration of human ability to resist almost perfectly a potentially fatal microbial disorder by a specifically acquired immunologic mechanism. T h e study of such a process should yield immunologic secrets more easily than equivalent effort directed against less perfectly resisted diseases, such as tuberculosis, which has received preponderant attention throughout the years. Although the massiveness of the original infecting dose of inhaled spores may help to determine which individuals are destined to succumb, this factor falls far short of total explanation. Several epidemics of histoplasmosis have been caused by the inhalation of large quantities of dust heavily contaminated with Histoplasma capsulatum, and the resulting inoculation must have been tremendously more massive than that of the average individual who acquires the infection; yet the percentage of cases in which dissemination occurred seems not to have been significantly higher in this group. In several instances students and laboratory technicians have become infected with apparently massive doses without any dissemination.

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Certain individuals possess at the time of acquiring the infection, or develop soon afterward, an important defect in the mechanisms by which most of their fellow sufferers acquire perfect specific immunologic resistance. In altogether too many instances disseminated histoplasmosis has been found together with a disease of the reticuloendothelial or of the hemopoietic system for the association to be accepted as coincidental. T h e lack of uniformity in the type of disease found thus associated— various forms of leukemia, lymphosarcoma, or Hodgkin's disease have been implicated—is also probably significant. A logical explanation is that the lymphoblastomatous disease process causes the reticuloendothelial system to fail in the performance of one of its most important duties, that of producing a specific antibody or antibodies necessary for the development of immunity. T h e reverse of this thesis, that histoplasmosis may induce changes in the reticuloendothelial system which result in a syndrome indistinguishable from one of the lymphoblastomata, is also possible, though more remotely so. It has frequently been pointed out that histoplasmosis, like other deep mycoses, is associated with other granulomatous disorders, especially tuberculosis, more often than coincidence would indicate. This observation is subject to several possible interpretations, among which our present knowledge does not permit us to discriminate. T h e presence of tuberculosis may cause a superimposed histoplasmosis infection to be poorly resisted and thus to disseminate; or the two diseases may simply act synergistically; or the same inherent defect in a patient's immunity mechanisms may similarly and simultaneously allow both diseases to develop into serious forms. According to Furcolow, there is as yet no proof that immunity in these two diseases is related, even though a five-year study of tuberculosis sanitariums has revealed a rather constant and statistically significant percentage of dual infections. Most of our understanding of the epidemiology of histoplasmosis has been derived from the study of patients' reactions to testing procedures. Various preparations of extracts of cultures of Histoplasma, called histoplasmins, have been used as antigens, first by van Pernis, Benson, and Holinger (1941), and later by Zarafonetis and Lindberg, Christie and Peterson, Palmer (1945), Howell, Furcolow, and Campbell. As this fungus is biphasic in culture, growing in a yeastlike phase at incubator temperature and producing only filaments and conidia at room temperature, it is at once apparent that extracts made from these different cultures could well have different potentialities. Additional differences are conferred upon the material by its method of extraction. It is therefore not surprising to find that workers who employ differing materials do not agree in their interpretations of reactions in relation to the disease and to immunity. Eventually it may be possible to select and standardize an antigen (or antigens) because of higher specificity and, more importantly, because of ability to assist the clinician in handling his cases—as the very useful

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coccidioidin does—and to abandon the less significant antigens except for research. T h e skin test

Histoplasmin is used in this test in the same manner as tuberculin; o.i cc of a dilution usually 1:1,000 is injected intracutaneously. T h e significance of the immediate flare reactions which are often observed remains obscure; they are apparently not related to the course of the disease. T h e delayed tuberculin type of reaction is the significant one; an erythematous papule at least 5 mm in diameter begins to be apparent within a few hours, and reaches its peak in about forty-eight hours. Almost all patients develop such reactivity, which may last for many years. This test has revealed that in certain geographic localities up to 80 percent of the population react positively (presumably because of having had this specific infection, and ignoring for the moment cross reactivity with other diseases), whereas other regions present no positive reactors because nobody has as yet been infected. This almost universal reactivity, developing shortly after infection, correlates well with the similarly almost universal tendency to resist the disease extremely well, and even seems to be related to the remarkable ability of most such persons to resist completely any subsequent reinfection from exogenous sources. (The reactivity seems to decline slowly with advancing years, and elderly people are again susceptible in higher percentages.) In many cases of the severe, disseminated, highly dangerous form of histoplasmosis, however, the skin test is negative (anergic) either because the potentiality to react never developed, or, if it did develop, subsequently disappeared. T h e clinician can utilize the ability to respond positively to the intradermal test as one sign pointing toward a good prognosis. T h e complement-fixation test

According to Furcolow, antibodies discoverable by the complementfixation test, using histoplasmin as the antigen, develop somewhat more slowly; about one-seventh of the patients develop them in two weeks, and six-sevenths, in four weeks. T h e titer usually remains low, persists for varying intervals (yeast-phase extracts show reactivity longer than mycelial-phase material), and gradually returns to negative in the absence of complications, which may cause the titer to remain positive for a number of years. If the disease is not being controlled, and the immunity is poor, the disease tends to disseminate, as indicated by a rising titer. T h e complement-fixation test thus has both diagnostic and prognostic titer, but the antibody it reveals has no power to confer immunity on the individual; indeed, the test appears to measure the extent and the activity of the infection rather than the immune response of the individual.

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T h e precipitin test with histoplasmin is in agreement with the complement-fixation test in 83 percent of the cases when the mycelial-phase antigen is used, but in only 14 percent with that from the yeast phase. A n agar-plate method of precipitin testing is said to be convenient and efficient. T h e colloidal particle agglutination tests (collodion or latex) are being studied currently, as are various gel-diffusion and fluorescentantibody techniques, but it is too early to judge their usefulness. As an intradermal test may produce a temporary rise in serologic titer, it is advisable to draw blood for the latter first, or at least within one week afterward. It will be seen that there is considerable similarity between the significance of these tests in histoplasmosis and coccidioidomycosis, and it seems likely that the mechanisms are fundamentally the same. THERAPY A host of drugs have been tried for histoplasmosis and abandoned; only sulfonamides (usually sulfadiazine) in very large and prolonged dosages have been used in the last few years. T h i s remedy should not be forgotten in cases intolerant of the recently more popular amphotericin B. Amphotericin B has proved to be by far the most helpful antifungal drug yet discovered for histoplasmosis. It is administered as described above (see chap. 3); no specific alterations are needed for this disease. Skin lesions are rare and should be considered as primary benign infections only under exceptional circumstances (e.g., when they are chancriform); otherwise they almost certainly indicate severe dissemination. Acute pulmonary histoplasmosis (the epidemic form) is rarely fatal, but regularly causes severe and protracted morbidity, for which several authors have recommended corticosteroids because of their anti-inflammatory effect. Because of the fear that this treatment might interfere in the development of immunologic resistance, amphotericin B has been used concomitantly, as well as alone, in similar cases for a short period of one to two weeks, usually with dramatic amelioration of both symptoms and X-ray abnormalities. T h i s treatment, it is believed, may reduce the incidence of late complications, such as obstructive phenomena due to enlarged or calcified lymph nodes, bronchiectasis, broncholithiasis, mediastinal fibrosis, pericarditis, collapse of lobes from bronchial obstruction, pressure upon the superior vena cava, diverticula of the esophagus, and perhaps adrenal insufficiency. Any of these may cause trouble because of scarring long after the actual infection has ceased; some of them can be corrected surgically, at least in part. Chronic, progressive pulmonary histoplasmosis is indicated by prolonged illness, with involvement spreading continuously and becoming more severe; when untreated, it has a mortality rate of about 30 percent.

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It is frequently mistaken for tuberculosis and only later correctly diagnosed, often after establishment of sanatorial care. Amphotericin B causes early conversion of sputum cultures to negative and resolution of pulmonary infiltrations. Disseminated histoplasmosis, when untreated, has a mortality rate of at least 80 percent for all ages. It is most common in infants and children less than ten years old, when it tends to be fatal within a year; in adults, the clinical course is more prolonged. Intensive specific drug therapy is mandatory and should be continued well into the recovery period, at least sixteen weeks. The presence of a high titer of complement fixation with histoplasmin in the serum, particularly if the skin test reveals a poor reactivity, must be considered to indicate probable dissemination, although the dividing lines do not seem to be so well established as they are in coccidioidomycosis. As in pulmonary tuberculosis, the surgical excision of localized, chronically persistent pulmonary lesions has been found to be of value in the treatment of histoplasmosis. Polk and Bailey (i960) recommend surgery for histoplasmosis showing coin-shaped lesions or solid masses more than 6 cm in diameter, right middle lobe syndrome, bronchiectasis, bronchial stenosis, acute lung abscess, destroyed lung, or empyema with or without bronchopleural fistula and cavitation. The last is the most frequent reason for surgery. Amphotericin B coverage is important. Surgery covered by amphotericin B has also been employed for histoplasmotic granuloma of the brain.

Bibliography Abildgaard, C . F., and R . L . Taylor. 1962. Histoplasmosis: survey of pre-school children in Panama. Amer. J . T r o p . Med. Hyg., 11:666. Ajello, L . 1954. Occurrence of Histoplasma capsulatura and oiher human pathogenic molds in Panamanian soil. Amer. J . T r o p . Med. Hyg., 3:897. . 1961. Observations on the epidemiology of histoplasmosis. Mycopathologia, 15:238. Ajello, L., D. W . Snow, W . G. Downs, and J . C. Moore. 1962. Occurrence of Histoplasma capsulatum on the island of Trinidad. Amer. J . T r o p . Med. Hyg., 11:245. Allison, F., Jr., M . G. Lancaster, A . E. Whitehead, and H. B. Woodbridge, Jr. 1962. Simultaneous infection in man by H. capsulatum and Blastomyces dermatitidis. Amer. J . Med., 32:476. André, M., J . Orio, R . Depoux, and E. Drouhet. 1959. African histoplasmosis in extensive form with multiple bone localizations: favorable outcome following surgical intervention and amphotericin B. [In French.] Bull. Soc. Pathol. Exot., 52:345. Babbitt, D. P., and B. A . Waisbren. i960. Epidemic pulmonary histoplasmosis: roentgenographic findings. Amer. J . Roentgenol., 83:236. Basset, A., M. Basset, and P. Hocquet. 1963. Cutaneous forms of African histo-

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plasmosis. [In French.] Bull. Soc. Franij. Dermatol. Syphil., 7o(Jan.-March):6i. Baum, G. L., R. A. Green, and J. Schwarz, i960. Enlarging pulmonary histoplasmoma. Amer. Rev. Respir. Diseases, 82:721. Baum, G. L., H. Rubel, and J. Schwarz. 1957. Treatment of experimental histoplasmosis. Antibiot. Ann., 1956-57:878. Baum, G. L., and J. Schwarz. 1958. Pulmonary histoplasmosis. New Engl. J. Med., 258:677. . i960. Clinical experiences with amphotericin B. Antibiot. Ann., 195960:638. . 1962. Chronic pulmonary histoplasmosis. Amer. J. Med., 33:873. Baum, G. L., J. Schwarz, and C. J. Wang. 1958. Treatment of experimental histoplasmosis with amphotericin B. Arch. Intern. Med., 101:84. Beard, H. W., J. H . Richert, and R . R. Taylor, i960. T h e treatment of deep mycotic infections with amphotericin B. Amer. Rev. Respir. Diseases, 81:43. Beatty, O. A., N. Levene, A . Saliba, and J. Coelho. 1962. Surgical therapy of chronic pulmonary histoplasmosis with and without amphotericin B. J. Thorac. Cardiovasc. Surg., 44:228. Bellin, E. L., M. F. Silva, and T . Lawyer, Jr. 1962. Central nervous system histoplasmosis. Neurology, 12:148. Campbell, C. C., G. B. Hill, and B. T . Falgout. 1962. Histoplasma capsulatum isolated from a feather pillow associated with histoplasmosis in an infant. Science, 136:1050. Cheesman, R. J., C. H. Hodgson, P. E. Bernatz, and L. A. Weed. i960. Surgical resection in the treatment of pulmonary histoplasmosis. Diseases of the Chest, 37=356Christie, A . 1958. T h e disease spectrum of human histoplasmosis. Ann. Intern. Med., 49:544. Christie, A., J. G. Middleton, J. C. Peterson, and D. L. McVickar. 1951. Histoplasmosis. Pediatrics, 7:7. Comparison of treated and untreated severe histoplasmosis: a Communicative Disease Center cooperative mycoses study. 1963. J. Amer. Med. Assoc., 183:823. Conrad, F. G., S. Saslaw, and R. J. Atwell. 1959. T h e protein manifestations of histoplasmosis as illustrated in 23 cases. Arch. Intern. Med., 104:692. Curry, F. J., and J. A. Wier. 1958. Histoplamosis: a review of 100 consecutive hospitalized patients. Amer. Rev. Tuberc. Pulmon. Diseases, 77:749. Darling, S. T . 1906. A protozoan general infection producing pseudo-tubercles in the lungs, and focal necrosis in the liver, spleen and lymph nodes. J. Amer. Med. Assoc., 46:1283. Da Rocha-Lima, H. 1912. Histoplasmosis. [In German.] Arch. Schiffs. Tropen. Hyg., Suppl. 79. . 1913. Beitrag zur kenntnis der Blastomykosen, Lymphangitis epizootica und Histoplasmosis. Zentr. Bakteriol., 67:233. De Monbreun, W. A. 1934. T h e cultivation and cultural characteristics of Darlings's Histoplasma capsulatum. Amer. J. Trop. Med., 14:93-125. Diveley, W., R. McCracken, W. Stoney, J. Guest, and V. McConnell. 1963. Surgical treatment of cavitary pulmonary histoplasmosis. J. Thorac. Cardiovasc. Surg., 45:101. Drouhet, E. 1958. Action de l'amphotericine B dans l'histoplasmose africaine ä

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grandes formes. [Action of amphotericin B in serious forms of African histoplasmosis.] Bull. Soc. Pathol. Exot., 51:75. . 196a. On histoplasmosis of major and minor types: four strains of H. capsulatum and seven strains of H. duboisii recently isolated. [In French.] Arch. Inst. Pasteur (Tunis), 39:291. Dubois, A., and R. van Breuseghem. 1952. African histoplasmosis. Bull. Acad. Roy. Mid. Belg., 17:551. Edwards, P. Q., L. Ajello, J. C. Moore, C. F. Jacobs, and D. L. Aronson. i960. Soil sampling in an urban focus of histoplasmin sensitivity. Amer. Rev. Respir. Diseases, 81:747. Edwards, P. Q., and C. E. Palmer. 1963. Nationwide histoplasmin sensitivity and histoplasmal infection. Public Health Repts., 78:241. Emmons, C. W. 1949. Isolation of Histoplasma capsulatum from soil. Public Health Repts., 64:892-896. . 1961. Isolation of Histoplasma capsulatum from soil in Washington, D.C. Public Health Repts., 76:591. Ettman, I. K., and W. D. Sutliff. 1963. Roentgenographs manifestations of pulmonary histoplasmosis, classified according ta clinical types. Diseases of the Chest, 43=587Forsee, J. H., and M. Pfotenhauer. i960. Surgical management of focalized histoplasmosis. J. Amer. Med. Assoc., 173:878. Furcolow, M. L. 1961. Airborne histoplasmosis. Bacteriol. Rev., 25(Sept.) ¡301. . 1962. Opportunism in histoplasmosis. Lab. Invest., 11:1134. . 1963. Tests of immunity in histoplasmosis. New Engl. J. Med., 268:357. Furcolow, M. L., and C. A. Brasher. 1956. Chronic progressive (cavitary) histoplasmosis as a problem in tuberculosis sanitoriums. Amer. Rev. Turberc. Pulmon. Diseases, 73:609. Furcolow, M. L., and R. W. Menges. 1952. Comparison of histoplasmin sensitivity rates among human beings and animals. Amer. J. Public Health, 42:926. Furcolow, M. L., F. E. Tosh, H. W . Larsh, H. J. Lynch, Jr., and G. Shaw. 1961. The emerging pattern of urban histoplasmosis. New Engl. J. Med., 264:1226. Gonzdlez-Ochoa, A. 1961. Increasing recognition of the severity of certain types of histoplasmosis. J. Amer. Med. Assoc., 17:325. Gonzdlez-Ochoa, A., and A. Cervantes-Ochoa. i960. Epidemic histoplasmosis and its prevention. [In Spanish.] Rev. Inst. Salubr. Enferm. Trop., 2o(Sept.):i29. Grunberg, E., and E. Titsworth. 1963. T h e effect of cortisone on mice with Histoplasma capsulatum. Amer. Rev. Respir. Diseases, 87:911. Hansmann, G. H., and J. R. Schencken. 1934. A unique infection in man caused by a new yeast-like organism, a pathogenic member of the genus Sepedonium. Amer. J. Pathol., 10:731-738. Hill, G. B., and C. C. Campbell. 1962. Commercially available histoplasmin sensitized latex particles in an agglutinin test for histoplasmosis. Mycopathologia, 18:169. Histoplasmosis Cooperative Study. I. Frequency of histoplasmosis among adult hospitalized males. 1961. Amer. Rev. Respir. Diseases, 84:663. Howard, D. H. 1960. Effect of mycostatin and fungizone on the growth of Histoplasma capsulatum in tissue culture. J. Bacteriol., 79:442. Ibach, M. J., H. W. Larsh, and M. L. Furcolow. 1954. Isolation of Histoplasma capsulatum from the air. Science, 119:71.

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Kaufman, L., and W. Kaplan. 1963. Serologic characterization of pathogenic fungi by means of fluorescent antibodies. J . Bacteriol., 85:986. Kaufman, L., J . H. Schubert, and W. Kaplan. 1962. Fluorescent antibody inhibition test for histoplasmosis. J . Lab. Clin. Med., 59:1033. Klugman, H. B., and H. I. Lurie. 1963. Systemic histoplasmosis in South Africa. S. African Med. J., 37:29. Larsh, H. W. i960. Natural and experimental epidemiology of histoplasmosis. Ann. N.Y. Acad. Sci., 89:78. . 1962. The prevalence and the drug resistance of Histoplasma capsulatum and Candida albicans in patients with pulmonary histoplasmosis. Lab. Invest., 11:1140. Little, J . A. i960. Benign primary pulmonary histoplasmosis as a common cause of unexplained fever in children. Southern Med. J., 53:1238. Little, J . A., J . Bruce, H. Andrews, K. Crawford, and G. McKinley. 1959. Treatment of disseminated infantile histoplasmosis with amphotericin B. Pediatrics, 24:1-6. Loewen, D. F., J . J . Procknow, and C. G. Loosli. i960. Chronic active pulmonary histoplasmosis with cavitation. Amer. J . Med., 28:252. Loosli, C. G., J . T . Grayston, E. R. Alexander, and F. Tanzi. 1952. Histoplasmosis. Amer. J . Hyg., 55:392. Louria, D. B., N. Feder, and C. W. Emmons. 1957. Amphotericin B in experimental histoplasmosis and cryptococcosis. Antibiot. Ann., 1956-57:870. Lynch, H. J., Jr., and K. L. Plexico. 1962. A rapid method for screening sputums for Histoplasma capsulatum employing the florescent antibody technique. New Engl. J . Med., 266:811. McDearman, S. C., and J . M. Young, i960. The development of positive serologic test with Histoplasma capsulatum antigens following single histoplasmin skin tests. Amer. J . Clin. Pathol., 34:434. McMahon, J . M., and C. R . Kessler. 1956. Histoplasmosis resembling pulmonary malignancy: treatment by pulmonary resection. Case report. J . Med. Assoc. Alabama, 25:221. McMillen, S., and S. Devroes. 1963. Specific precipitin bands in serology of histoplasmosis. Amer. Rev. Respir. Diseases, 87:438. Menges, R . W., M. L. Furcolow, H. W. Larsh, and A. Hinton. 1952. Laboratory studies on histoplasmosis. I. The effect of humidity and temperature on the growth of Histoplasma capsulatum. J . Infect. Diseases, 90:67. Miller, J . M., M. Ginsberg, H. R . Johnson, and A. Bogosian. 1958. The treatment of histoplasmosis with amphotericin B (fungizone). Antibiot. Med. Clin. Ther., 5-59SMochi, A., and P. Q. Edwards. 1952. Geographical distribution of histoplasmosis and histoplasmin sensitivity. Bull. World Health Org., 5:259, 290. Murdock, W. T., R . E. Travis, W. D. Sutliff, and L. Ajello. 1962. Acute pulmonary histoplasmosis after exposure to soil contaminated by starling excreta. J . Amer. Med. Assoc., 179:73. Nicholas, W. M., J . A. Wier, L. R. Kuhn, C. C. Campbell, L. B. Nolte, and G. B. Hill. 1961. Serologic effect of histoplasmin skin testing. Amer. Rev. Respir. Diseases, 83:276. Nilzen, A., and H. Paldrok. 1953. A laboratory infection caused by Histoplasma capsulatum. Acta Dermato-venereol., 33:339.

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Palmer, C. E. 1945. Non-tuberculous pulmonary calcification in sensitivity to histoplasmin. Public Health Repts., 60:513. . 1946. Geographic differences in sensitivity to histoplasmin among student nurses. Public Health Repts., 61:475. Peterson, J. C., and A. Christie. 1948. Histoplasmosis. Amer. Rev. Tuberc. Pulmon. Diseases, 57:361. Polk, J. W. ig6o. Surgery for pulmonary histoplasmosis. In Henry C. Sweany, ed., Histoplasmosis. Springfield, 111.: Charles C Thomas. Polk, J. W., and A. H. Bailey, i960. Surgical treatment of histoplasmosis. Minnesota Med., 43(Oct.):65Polk, J. W., J. A. Cubiles, and W. W. Buckingham. 1957. T h e surgical treatment of chronic progressive pulmonary histoplasmosis. J. Thorac. Surg., 34:323. Procknow, J . J., A. P. Connelly, Jr., and C. G. Ray. 1962. Fluorescent antibody technique in histoplasmosis (animal experimentation). Arch. Pathol., 73:313Procknow, J. J., and C. G. Loosli. 1958. Treatment of the deep mycoses. Arch. Intern. Med., 101:765. Quiroga, M. I., A. R. Copello, P. H. Magnin, and M. J. Somoza. 1962. Histoplasmosis with meningoencephalic location. [In Spanish.] Prensa M6d. Argentin., 49:1060. Resseler, J . J., H. L. Farrior, and R. van Breuseghem. 1962. Congolese cases of histoplasmosis due to H. duboisii. [In French.] Ann. Soc. Beige M6d. Trop., 42:801. Richert, J. H., and C. C. Campbell. 1962. T h e significance of skin and serologic tests in the diagnosis of pulmonary residuals of histoplasmosis. Amer. Rev. Respir. Diseases, 86:381. Rubin, H., M. L. Furcolow, J. L. Yates, and C. A. Brasher. 1959. T h e course and prognosis of histoplasmosis. Amer. J. Med., 27:278. Rubin, H., P. H. Lehan, and M. L. Furcolow. 1957. Severe nonfatal histoplasmosis: report of a typical case, with comments on therapy. New Engl. J. Med., 257:599Saliba, A., O. A. Beatty, and A. Pakalns. i960. A study of pulmonary histoplasmosis with particular reference to pneumoperitoneum therapy. Amer. Rev. Respir. Diseases, 81:709. Schubert, J. H., H. J. Lynch, Jr., and L. Ajello. 1961. Evaluation of the agar plate precipitin test for histoplasmosis. Amer. Rev. Respir. Diseases, 84:845. Schwarz, J., and G. L. Baum. 1953. Giant forms of Histoplasma capsulatum. Amer. J. Clin. Pathol., 23:897. . 1963a. Reinfection in histoplasmosis. Arch. Pathol., 75:475. 19636. Histoplasmosis, 1962. Arch. Intern. Med., 111:710. Schwarz, J., G. L. Baum, and M. Straub. 1961. Cavitary histoplasmosis complicated by fungus ball. Amer. J. Med., 31:692. Sorensen, L. J., and E. E. Evans. 1954. Antigenic fractions specific for Histoplasma capsulatum in complement fixation reaction. Proc. Soc. Exptl. Biol. Med., 87:339. Sutliff, W. D. i960. Randomized amphotericin B therapy of chronic pulmonary histoplasmosis: report of VA-Armed Forces cooperative study of histoplasmosis. Trans. 19th Conf. Chemother. Tuberc. Pp. 316-319. Takaro, T., H . E. Walkup, and J. H. Matthews. 1959. T h e place of excisional

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surgery in the treatment of pulmonary mycotic infections. Diseases of the Chest, 36:19. Taylor, R. L., and C. G. Dobrovolny. i960. T h e distribution of histoplasmin sensitivity in Guatemala. Amer. J. Trop. Med. Hyg., 9:518. Tegiris, A . S., and D. T . Smith. 1958. Acute disseminated pulmonary histoplasmosis treated with cortisone and MRD-112. Ann. Intern. Med., 48:144. Van Pernis, P. A., M. E. Benson, and P. H. Holinger. 1941. Specific cutaneous reactions with histoplasmosis. J. Amer. Med. Assoc., 117:436. Walker, W. J., and E. C. James. 1959. Pulmonary histoplasmosis. Canad. Med. Assoc. J., 81:486. Yates, J. L., M. V. Atay, H. V. Langelutting, C. A. Brasher, and M. L. Furcolow. i960. Experience with amphotericin B in the therapy of histoplasmosis. Diseases of the Chest., 37:144. Zeidberg, L. D., L. Ajello, A. Dillon, and L. C. Runyon. 1952. Isolation of Histoplasrna from soil. Amer. J. Public Health, 42:930-935.

7 North American blastomycosis

INTRODUCTION Blastomyces dermatitidis, occasionally causes a chronic suppurative granulomatous disease in the human body, almost always in one of two widely divergent forms. In one form, the skin alone is affected, possibly for many years; the disease is usually sharply localized in one area of the body, and the general health of the patient is not impaired. In the other form, the lungs seem to be the primary focus from which the disease is commonly disseminated to many parts of the body, usually causing death. W h e n the term "blastomycosis" is used without an accompanying adjective, the latter is meant. A DIPHASIC FUNGUS,

HISTORY In 1894 Gilchrist presented to the American Dermatologic Association a preliminary report on a patient who had a skin disease unlike any that had been previously described; he correctly attributed the disorder to a 84

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microorganism appearing in the tissues as a budding yeast. T w o years later he published a detailed study (Gilchrist and Stokes, 1896) of this case, and in 1898, in collaboration with Stokes, he named the causative fungus Blastomyces dermatitidis. T h e disorder soon became known as blastomycosis, or Gilchrist's disease. Numerous similar cases were reported in the next few decades, and in some of them the disorder involved internal organs as well as the skin. It soon became apparent, however, that Gilchrist's disease was often confused with other deep fungous diseases in which the organisms in the tissues sometimes appear as spherules, namely, cryptococcosis (torulosis), coccidioidomycosis, and South American blastomycosis. T h e confusion was not resolved until the early 1930's, when methods of differentiating among these diseases were clarified by de Almeida and by Benham (1934). During the half century that followed the original discovery, it became firmly established that North American blastomycosis exists in the two markedly different forms noted above. Rarely was a combination of the two forms reported, or even a transition from one to the other. This sharp differentiation was universally attributed entirely to the route by which the infecting fungi entered the body. Inoculation of the organisms directly into the skin caused the chronic cutaneous form, whereas their inhalation into the lungs resulted in the disseminated visceral type. By 1951, however, Schwarz and Baum, after extensively studying blastomycosis from the pathologist's viewpoint, had discovered that painstaking investigation of cases of the chronic cutaneous type usually revealed evidence of concomitant or preceding pulmonary involvement. Strongly impressed by the regularity of this finding in so large a percentage of cases, they became convinced that the phenomenon probably exists in all cases, even though at times too minor or evanescent to be detectable. They concluded, therefore, that the chronic, cutaneous type is simply another manifestation of the way in which dissemination from a pulmonary focus can occur, contrasting sharply with the widespread visceral involvement previously alone considered typical. In support of this view Schwarz and Baum (1952) pointed out that in three instances in which Blastomyces dermatitidis was known to have been inoculated directly into the skin of previously uninfected individuals, not one case of the ordinary chronic, cutaneous form of the disease resulted. O n the contrary, the patients all exhibited a chancriform picture, closely resembling the usual form of sporotrichosis. T h e following year we were privileged, among others, to observe the case of a mortuary attendant who became infected with B. dermatitidis through a puncture wound in a finger sustained while preparing the body of a person dead of the disseminated form of blastomycosis. T h e clinical picture that evolved was typically chancriform, and in no way resembled the ordinary chronic, cutaneous type. Subsequently Wilson, Cawley, Weidman, and

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Gilmer studied all four of these cases and reported them in detail (1955). T h e y considered the evidence sufficiently conclusive to establish this type as an entity, called primary cutaneous blastomycosis (to be discussed in detail later). In 1955 Smith, Harris, Conant, and Smith, reporting studies on a small but highly interesting and instructive epidemic in North Carolina, revealed that several presumably normal persons, w h o had no history suggestive of this disease but w h o had been living in a region where some cases had been discovered, reacted positively to the intracutaneous test with blastomycin. T h e i r finding suggests that blastomycosis may also exist in a form so mild as to remain entirely subclinical, as do coccidioidomycosis and histoplasmosis. ETIOLOGY A single species of fungus, usually called Blastomyces dermatitidis, is responsible for North American blastomycosis. T h e name is not botanically correct, and is therefore subject to change when the correct position of the species has been established, and the question is less controversial than at present. DISTRIBUTION North American blastomycosis is well named, because it is limited practically (and probably entirely) to that continent. Its distribution is actually further restricted to the northern part of the Mississippi Valley and to the O h i o Valley, with a subsidiary focus in the Middle Atlantic states. T h e patients in most cases discovered elsewhere are found to have resided fairly recently in one of these areas. North American blastomycosis has therefore been nicknamed "the Chicago disease." A l t h o u g h apparently no age is exempt, the majority of cases have occurred between the ages of twenty and forty. A s is common in the other systemic mycoses, more males than females are afflicted; the ratio is as high as 15 to 1 in some studies. N o race seems to be more susceptible to the disease than others, nor does skin color seem to play a part. EPIDEMIOLOGY It appears obvious that man acquires North American blastomycosis by obtaining the fungus from some exogenous source in nature, but there are only a very few reports of its recovery in culture from any such source. T h e first report, by Stober in 1914, was not confirmed until 1961, when A j e l l o succeeded in growing the fungus from a soil sample. Delamater and Emmons have both demonstrated that it will grow on soil in the

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laboratory. Although the exact manner in which the fungus enters the body remains doubtful, there is evidence of pulmonary involvement in so high a percentage of cases of all types that almost certainly the disease results from inhalation of airborne spores. It was formerly believed that the infection in the commonest form of the disease, the chronic cutaneous type, was acquired by direct inoculation of the fungus into the skin. Recent studies render this conclusion much less certain, for the cutaneous type has often been preceded by pulmonary involvement, and is therefore thé result of secondary dissemination. In four proved instances of percutaneous inoculation a different syndrome developed. In most of sixteen cases observed in dogs by Ramsay and Carter there were pulmonary as well as skin lesions. N o instances of transmission from animals to man or from man to man have been reported. CLINICAL

CHARACTERISTICS

North American blastomycosis is conveniently discussed under four headings: primary cutaneous, primary pulmonary, chronic cutaneous, and disseminated, although there is undoubtedly much overlapping among the last three. Primary cutaneous blastomycosis Although extremely rare and accordingly warranting no such priority, this type will be taken up first because the other three more common forms merge into one another, and continuity in their discussion is desirable. In the four known cases, primary inoculation of B. dermatitidis into the skin of human beings caused a papule to appear at the inoculation site in a week or so, followed in about two weeks by lymphangitis and lymphadenopathy, which remained localized to the affected limb. In two cases, several tender nodules developed along the course of the lymphangitic vessels, resembling closely the usual picture of sporotrichosis. Although the evidence is not conclusive, it is likely that blastomycosis acquired in this manner is much milder than the other forms, and that it heals completely and spontaneously in most instances. T h e primary lesion was excised in three cases, and the lymph nodes in the fourth, but in no case were both of these infected areas extirpated. Nevertheless, all patients had entirely recovered within four months, without developing the chronic, localized cutaneous form of the disease or sustaining dissemination. None of these patients showed recurrence in periods of 44, 29, 6, and 4 years, respectively. T h e importance of discussing so rare a phenomenon is to induce in the clinician a reluctance to accept an apparently logical intracutaneous inoculation as the cause of his patient's disease. He should not rely on

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local treatment alone until extensive search, together with skin and serological testing, establishes that the disease is absent elsewhere. Primary pulmonary blastomycosis Although much evidence indicates that the lungs are frequently, if not, indeed, almost invariably, the portal of entry for blastomycosis, the resulting disease is so insidious in its development that little is known of the early primary phases. At first the infection closely resembles an ordinary subacute respiratory infection, presenting itself as a nonproductive cough accompanied by moderate fever, chest pain, and perhaps dyspnea. These symptoms gradually increase in severity; bloody and purulent sputum appears; and weakness, anorexia, and loss of weight afflict the patient. The fever becomes more pronounced and night sweats often occur. Pleurisy is occasionally observed. Recent reports of erythema nodosum are reminiscent of its frequent accompaniment of coccidioidomycosis in the same stage. Little is known of pulmonary blastomycosis in a mild form, as is recognized in coccidioidomycosis. It is difficult to differentiate severe pulmonary blastomycosis from massive tuberculosis or lung abscess by physical examination, unless the infection erodes through the chest wall to form discharging sinuses in the skin, which happens very rarely. X-ray examination of the chest may reveal extensive enlargement of the mediastinal nodes, but this feature is often hidden by massive densities projecting irregularly from that area, in a manner strongly suggesting bronchogenic carcinoma. There may be only unilateral involvement at first, but later the other lung usually becomes infected. Cavity formation is not common, and such lesions are usually small and irregular in outline. Occasionally there is evidence of massive miliary spreading. Sometimes the patient slowly recovers; sometimes death occurs while the disease is still confined to the lungs. More frequently, however, dissemination to extrapulmonary areas occurs. Disseminated blastomycosis Disseminated blastomycosis is caused by hematogenous spread of the fungi from the lungs to other parts of the body. The skin is involved in a large percentage of cases, and the bones, most commonly the ribs and the vertebrae, are affected in perhaps two-thirds of the cases. Bony lesions seen in X-rays reveal both destructive and proliferative processes, resembling those produced by tuberculosis more than the cystlike lesions of coccidioidomycosis, but less proliferative than actinomycosis. Compression of the spinal cord may result from the collapse of vertebral bodies. Involvement of the viscera, especially liver, spleen, kidneys, and prostate, is common. About one-third of the cases show central nervous system lesions, and meningitis or brain abscesses are not rare. In striking contrast with South American blastomycosis, the intestinal tract is usually spared.

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Fig. 5. North American blastomycosis: infiltration in lungs. Extensive, soft, coarsely nodular, and confluent infiltration throughout both lungs.

Anemia of the hypochromic type is typically present, and usually leucocytosis, predominantly polymorphonuclear. The sedimentation rate is heightened. Chronic cutaneous blastomycosis This most common form of North American blastomycosis is first observed as a cutaneous lesion, and apparently remains limited to the skin throughout a chronic course extending over many years. Until recently it has been assumed that this type of infection was caused by direct inoculation of the organisms at the point where the initial lesion appeared.

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Since the realization that an entirely different chancriform syndrome developed in the four cases where cutaneous inoculation was known to have occurred, it has become necessary to explain the chronic cutaneous form in one of two different ways: (1) It actually does result from direct inoculation of the fungi into the skin of a person w h o has previously had the same infection, probably in the lungs, and whose immunological status has thereby been at least partly altered; or (2) it is simply a special type of the disseminated disease. T h e latter situation is probably predominant. Regardless of arguments as to its mode of origin, localized cutaneous blastomycosis begins either as an isolated papular lesion in or just below the skin, or as a subcutaneous nodule developing into an abscess and eventually rupturing to form an ulcer. T h e lesion soon takes on a verrucous appearance, studded with tiny pustules, the whole being raised above the level of the surrounding skin by a few millimeters. T h e r e is slow peripheral extension until the lesion is a few centimeters in diameter, at which time the central area begins to subside, finally healing completely by the formation of a soft atrophic noncontractile scar. Other lesions may appear, either originating, as did the first, from the primary pulmonary focus, or formed by direct transplantation of the organisms from the skin lesions to a new area of the skin; by irregular peripheral growth and coalescence, gyrate, arciform, and serpiginous forms are produced. Over many years of this process, lesions may eventually cover large areas, perhaps as much as a sixth, of the body surface, but there is a strong tendency for them to remain roughly contiguous to the point of first appearance. A t the borders of these lesions there is a characteristic verrucous ridge a few millimeters in height, with many pustules and exudative crusts on its crest, the whole resting on a tumid, violaceous base which terminates abruptly at the edge of the normal surrounding skin centrifugally, and equally precipitously in scarred atrophy at the center. T h i s entire process has been appropriately likened to a fire in a field of grass or grain; islands of skin are often left untouched, or islands of activity may remain long after their separation from the main mass of the infection. In contrast with syphilis, which never returns to areas it has once abandoned, blastomycosis sometimes recurs in areas already scarred. PATHOLOGY T h e r e is considerable variation in the pathologic changes produced in different stages of the disease. Primary cutaneous infection T h i s stage is characterized by a dense infiltrate of leucocytes, predominantly of the polymorphonuclear type, within which can be seen the singly budding cells of Blastomyces dermatitidis. In the early phases of the infec-

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tion these organisms are numerous, but later they decrease markedly in number. The lymphangitic streak reveals an inflammatory infiltrate containing a multiplicity of cell types and numerous blastomycetes. The lymph nodes reveal foci of acute granulomatous lymphadenitis, in which are giant cells occasionally containing the fungus organisms. Primary pulmonary infection In this stage there may be changes that grossly resemble carcinoma or tuberculosis. Nodules of all sizes, some of them caseous, abscesses, and occasionally cavitation are seen. Pleural thickening is common, and frequently the disease extends beyond the pleura to the ribs, and sometimes even penetrates the chest wall and discharges externally. Involvement of the lungs is almost always extensive in patients dying of blastomycosis; the organisms, usually present in enormous numbers, are accompanied by a comparatively slight degree of cellular inflammatory reaction, indicating an almost complete absence of host resistance. Disseminated blastomycosis Many organs are involved, and the lesions contain more organisms as the disease progresses and the efforts of the tissues to combat the infection become weaker. In the earlier stages the lesions are purulent; later, tubercles, necrotic zones, and abscesses appear. Bony lesions frequently result in subcutaneous abscesses or sinuses draining through the skin. There may be focal lesions in muscles. Pericarditis with effusion has been reported. So many organisms may be present in autopsy material as to appear almost as though in pure culture, the body of the host having long since ceased to offer much immunologic or cellular resistance to their multiplication. This picture is in striking contrast with that seen in the chronic cutaneous form of blastomycosis. Chronic localized cutaneous blastomycosis Here the pathologic picture differs markedly from that in the forms described above. Acanthosis, developed to a more marked degree than in any other known disease, assumes to the highest degree the condition called pseudoepitheliomatous hyperplasia, frequently mistaken for squamous cell carcinoma. The pus in the numerous microabscesses, many of them entirely contained within the thickened epidermis, is composed largely of polymorphonuclear leucocytes and some lymphocytes. Within these microabscesses an occasional fungus cell can be seen; in fact, this is the best place to look for these organisms. Yet even in the microabscesses they are so sparsely distributed that the experienced histopathologist may have to search through a dozen or more serially cut sections before being rewarded. Below the extremely irregular boundary of the epidermis there

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is a band of dense infiltrate consisting of leucocytes among which polymorphonuclear cells predominate. Some of the giant cells which are often seen contain fungus elements. W i t h i n all this active mass there is practically no connective tissue stroma, but many dilated blood vessels are present. Fungus cells are discerned here only rarely. In sections taken from areas where the disease is subsiding, fibrosis is present, but it is usually not firm or dense. DIFFERENTIAL

DIAGNOSIS

North American blastomycosis may be diagnosed by the discovery of the typical organisms in direct microscopic examinations of exudates, or in histopathologic preparations of tissues, as well as by cultural methods. T h e periodic acid-Schiff stain (Hotchkiss-McManus, popularized by Kligman and Mescon) is a valuable adjunct, as it stains fungus cells differentially. Blastomyces dermatitidis can usually be recovered in culture, but the technique, often requiring specialized media arid incubation, is not easy. Presumptive diagnosis by serologic reactions and skin tests (to be discussed later) is also possible. T h e primary cutaneous (chancriform) type occurs so rarely as to need little in the way of further discussion. It must be differentiated from the similar stage of other microbial diseases. T h e primary pulmonary form must be differentiated from a wide range of lung diseases, principally pneumonia, tuberculosis, silicosis, other deep mycoses, and neoplasm. T h e disseminated form may simulate many disorders, most commonly tuberculosis, syphilis, neoplasms, or other deep mycoses. T h e chronic cutaneous type must be differentiated from tuberculosis verrucosa cutis; from the comparable verrucous stages of coccidioidomycosis, chromoblastomycosis, sporotrichosis, and syphilis; and from bromoderma, iododerma, and granuloma inguinale. MYCOLOGY T h e most widely accepted name for the fungus that causes North American blastomycosis is Blastomyces dermatitidis, given to it by Gilchrist and Stokes in 1898. As the term Blastomyces had previously been used to designate a different genus, it was not available for its present usage, according to the rules of botanical nomenclature. Of the several names suggested for this organism (the commonest being Zymonema or Endomyces), none has w o n universal agreement. It seems best to continue to call it Blastomyces until further knowledge about its life cycle and its habitat in nature yields better clues. B. dermatitidis is biphasic, as are s'everal other fungi capable of causing deep mycoses. In animal and human tissues it exists only as spherules which usually are nearly spherical, varying in size from 7 to 15 microns,

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with a wall often almost i micron in thickness; the wall makes the spherules appear by refraction under the microscope to have a double outline. T h e fungus reproduces in such tissues only by budding, producing daughter cells one at a time. A bud, or daughter cell, begins as a thin-walled bubble with a wide area of attachment to the mother cell. T h e two cells remain so attached until the daughter cell, to which nuclear material is transferred through the area of attachment, almost reaches the size of the mother cell; during the process of growth the wall gradually becomes thicker. Some authors have stated that it is difficult to differentiate this organism from Coccidioides, but close observation always reveals completed cross walls between any two adherent cells of the latter organism, as they are really only two sibling cells; neither was formed from the other by budding, but both were simultaneously produced in the same large mother cell. Although at times three or more cells of B. dermatitidis may appear to be grouped together, close observation reveals that there is always final separation between a mother cell and a daughter cell by completion of their walls at the point of connection before either begins to produce another bud. This process sharply differentiates B. dermatitidis from B. brasiliensis, which often produces multiple buds on the same mother cell before separating any of them. For direct microscopic examination it is advantageous to prepare slides in two ways (see mycology section in chap. 4), one using K O H solution and the other using saline. A miniature room-temperature culture results from the latter, and within a day or two each fungus cell will produce a "sprout" consisting of a hyphal thread; there is only one to each spherule, in contrast with Coccidioides which, when similarly treated, produces several hyphae per cell. This method sometimes provides a definitive diagnosis earlier than culture methods or histopathologic preparations. In histopathologic sections the organisms appear as described in the preceding paragraphs. Hematoxylin does not stain the cell walls well, but the nuclear material takes it deeply, and is usually seen to occupy more than half of the cell. PAS staining reveals the cell walls excellently, and, by providing a sharp contrast between fungal and nonfungal material, often reveals organisms that would otherwise be missed. In sections of skin it is best to search in the intraepidermal microabscesses characteristic of the common chronic cutaneous type of this disease, as one or more cells are almost invariably present in the center of such a structure. T h e second choice is to search in giant cells in the subepidermal infiltrate. Several authors have described cases showing much smaller organisms, only 2 or 3 microns in diameter, interspersed with the ordinary forms. Some of these may actually have been Histoplasma in patients afflicted with a double infection with both fungi, as suggested by Weed. Cultures should be implanted on several types of media, including enriched types such as brain-heart infusion agar with added blood. Anti-

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biotics cannot be used in incubator culturing. Examples of each should be held at room temperature as well as in the incubator. B. dermatitidis is often difficult to recover in culture, not only because it is inherently more unwilling to adapt itself to captivity, but because it is often present in the inoculating material only in small numbers, mixed with hundreds of times as many leucocytes and a generous supply of bacterial competitors. T h i s is especially true of the chronic cutaneous form, where the patient's immunologic and cellular resistance mechanisms are intensely active, but less so, of course, in the disseminated disease threatening to life. T h e fungus grows slowly at 37 ° C as the yeastlike form, producing, in about two weeks, cream-colored, waxy colonies which become wrinkled as they age. Microscopically, the singly budding spherules can be seen as described above, with only an occasional abortive attempt to send forth a short-stemmed hypha-like strand. In the early phases colonies are difficult to differentiate from those of the bacteria which so often predominate, and microscopic investigation is necessary. A t room temperature the growth is moist and glabrous at first but soon a fluffy aerial mycelium develops, and a downy colony results, white at first but often becoming cream-colored or light brown. Sometimes a prickly appearance develops because of the formation of twisted aggregates of several hyphal strands called coremia, not diagnostic of this fungus but highly suggestive in differentiating it from other deep mycotic pathogens. Microscopic examination of material from these colonies usually reveals the distinctive conidia which are borne terminally on the tips of short stems called conidiophores, as well as along the sides of the hyphae themselves. These are 3 to 5 microns in diameter, and are round, oval, or pearshaped. T h e y are thin-walled at first and the contents are homogenous, but later they enlarge and the walls thicken, the contents then appearing granular. It is often helpful to observe the ability of this fungus to change its form when moved from the incubator to room temperature, and vice versa. Sometimes this process requires passage through animals. Guinea pigs or mice serve this purpose, and also assist in isolating the fungus from specimens taken from active lesions. Intraperitoneal injection produces typical lesions in mesentery, liver, spleen, lungs, and lymph nodes, where the organisms are present in much larger concentrations than in the original material. T h e addition of 5 percent gastric mucin to the injection material helps in producing extensive involvement (Strauss and Kligman). IMMUNOLOGY Martin, as early as 1935 (and later with D. T . Smith), showed the usefulness of testing procedures employing extracts of cultures of B. dermatitidis by intracutaneous injection into patients, as well as by serologic

13. North American blastomycosis: chronic cutaneous form. Upper left: solitary cutaneous lesion, not of chancriform type, hence not due to primary inoculation at this point, but probably disseminated from primary pulmonary focus. Upper right and middle left: same stage of disease, but multiple localized lesions. Middle right: ulcerative skin lesions accompanying severe disseminated disease involving orbit and viscera also. Lower left and lower right: chronic cutaneous form, remaining localized while slowly spreading peripherally for years. PLATE

P L A T E 14. North American blastomycosis: chronic cutaneous form. Upper left: skin testing in chronic cutaneous blastomycosis; control saline negative, blastomycin positive 1 : 1 0 0 ; coccidioidin negative; histoplasmin positive, but in dilution of 1 : 1 0 ; tuberculin positive. Upper and lower right: chronic cutaneous blastomycosis, comparatively early lesions, not yet clearing in center. Lower left and middle right: chronic cutaneous form after years of gradual peripheral spread and central clearing (note reinfection in previously healed areas, in contrast with syphilis).

P L A T E I 5. North American blastomycosis: cutaneous lesions and histopathology. Upper left: chronic cutaneous form, solitary skin lesion. Lower left: same, after successful therapy with stilbamidine. Upper right: histopathologic appearance of skin in chronic cutaneous form, showing intraepidermal abscesses, pseudoepitheliomatous hyperplasia, and dense cellular infiltrate (H & E x 100). Middle right: intraepidermal microabscess (H & E X400). Lower right: intraepidermal microabscess, showing budding cell of Blastomyces dermatitidis within dense cellular infiltrate (H & E X900).

16. North American blastomycosis: histopathology and cultural characteristics. Upper left: B. dermatitidis in tissue (note early asteroid form) (H & E x6oo). Upper middle left: same (PAS x8oo). Lower middle left: typical budding cell within giant cell (H & E x 800). Lower left: residual fungal cells in fibrosing area (PAS x 800). Upper right: B. dermatitidis (with Gridley stain x 600). Middle right: gross appearance of culture of B. dermatitidis, yeast phase when grown at 37°C. Lower right: same in filamentous mycelial phase when grown at 20°C. PLATE

17. South American blastomycosis (paracoccidioidomycosis): cutaneous lesions on face. Upper and lower left: chronic verrucous and granulomatous type. Upper and lower right: same, but illustrating predilection for mucous membranes. PLATE

18. South American blastomycosis: ulceroglandular form. Upper left: lymphatic involvement of neck, with multiple draining sinuses and skin infection resembling scrofuloderma. Lower left: chronic verrucous form widespread over body. Upper right: involvement of lips. Lower right: Jorge Lobo's disease, perhaps a variant of South American blastomycosis, or a distinct entity. PLATE

19. South American blastomycosis: histopathology. Upper left : histopathologic picture of accidental intracutaneous inoculation in human finger (H & E x i o o ) . Lower left and upper right: histopathologic picture of severely infected subcutaneous tissue (H & E x 200 and x 400). Middle right : infected lung tissue (PAS X400). Lower right: most typical "marine pilot's wheel" form (PAS X400). PLATE

20. South American blastomycosis: histopathology and cultural characteristics. Upper left: multiple budding form from culture at incubator temperature (PAS X400). Upper right: same form in tissue (Gridley stain x 1,000). Middle right: same form in tissue (PAS X400). Middle left: gross appearance of culture at incubator temperature, yeastlike form. Lower left: gross appearance of culture at room temperature, filamentous form. Lower right: microscopic appearance of room-temperature culture, showing hyphae bearing microconidia (PAS x 100). PLATE

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complement-fixation techniques. It was clear that the antibodies revealed by these procedures could not be identical, because either could be present in almost any amount with or without the other. Patients who reacted strongly to the skin test by producing the delayed tuberculin type of response had in general a better prognosis, especially if the complementfixation titer in their serums was absent or low; the reversal of these phenomena was usually associated with highly dangerous, extensive disease, and probable death. T h e patient's own immunologic contribution toward fighting the disease was obviously a valuable adjunct to any other therapy. This reaction has been repeatedly emphasized ever since, and must always be taken into consideration in evaluating any drug therapy. T h a t there are persons who acquire pulmonary blastomycosis, but maintain it entirely in a subclinical phase or exhibit only mild symptoms while they successfully develop complete immunologic resistance, is not yet well established. In coccidioidomycosis, it will be recalled, more than 60 percent of those affected remain entirely asymptomatic during the entire course of the disease. This situation is revealed by the high percentage of persons who, after a few years of residence in known endemic areas, develop the ability to react specifically to the skin test with coccidioidin. Blastomycin has not been so widely used in testing normal persons as has coccidioidin, but the surveys do warrant the conclusion that, even in the most endemic areas for blastomycosis, the percentage of those who react to it, thereby revealing a previous "silent" infection, is not large. Several possible reasons for this variation come immediately to mind: the organisms are almost certainly not so profusely distributed in the environment as are those of Coccidioides (indeed, the reservoir in nature for B. dermatitidis has not been well outlined); the organisms are therefore probably not inhaled by large numbers of people in sufficient quantities to transmit the infection; or they are relatively nonvirulent, as compared with those of Coccidioides. Perhaps all these factors are operative. It seems certain also that the human body does not acquire effective immunologic resistance to blastomycosis as easily as it does to coccidioidomycosis, so that probably a much higher percentage of those who do become infected develop the disease in a serious form. It is quite probable, however, that there are some silent cases of blastomycosis. It is extremely significant that Smith, Harris, Conant, and Smith (1955), while investigating a small but instructive epidemic in North Carolina, found several normal persons who reacted positively to the intracutaneous injection of blastomycin and must therefore be presumed to fall into this category, even though no clinically evident illness was recalled. Some of the so-called false positive reactors to the skin test, reported from time to time by other observers, may also be of the same type. Further developments in. this field are to be anticipated. Many instances of recognized pulmonary blastomycosis have been ac-

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companied by lesions in other organs or in the skin, indicating dissemination; sometimes, indeed, the infection has been recognized while still localized in the lungs, with the process of dissemination just beginning. We know of no cases, however, in which the sequence has been reversed, that is, in which skin lesions were present while the lungs were demonstrably clear, only to become involved later. In other words, dissemination seems to occur in one direction only, from the lungs to the skin. (That the reverse route might be followed after primary cutaneous inoculation cannot be denied, but it has not yet been demonstrated; in the four known cases of this type the infection failed to spread in this manner.) Moreover, when pulmonary blastomycosis is present in an active stage accompanied by skin lesions, the latter can usually be shown to have first appeared only a short time previously, usually less than a year. Conversely, in cases of the chronic cutaneous type whose history indicates that the skin infection has been present for many years, the lungs usually are not found to be actively involved. It is logical, therefore, to conclude that in such cases the lungs (which, according to the recent concept, were often the original primary focus) have long ago healed, and are no longer susceptible to reinfection backward from the skin. Carrying this inference still further, it appears that a patient either dies early in the course of disseminated blastomycosis, or resists it immunologically to a sufficient degree to clear it entirely from the lungs (leaving them thereafter immune to reinfection), but not always completely from the skin, which may continue to be involved for many years in the chronic, cutaneous form. That this chronic form, so well known for sixty years and formerly attributed to direct cutaneous inoculation, is instead often the residual of an old dissemination from a primary pulmonary focus, is a recent concept; it has not been generally accepted, but we believe the evidence is sufficient to prove it correct. Most important of all is the recently demonstrated fact that this type of disease did not develop in any of the four cases known to have acquired the infection by skin inoculation. It may seem odd to claim that the lungs of an individual may possess the ability to resist blastomycosis completely by immunologic means, whereas in many cases the skin, which may be involved for years, obviously does not. One explanation that seems to fit is apparently supported by certain allergic and immunologic phenomena (soon to be discussed). From a clinical and pathologic standpoint it is evident, for several reasons, that the skin, which frequently fails to develop complete resistance (that is, sufficient to achieve a spontaneous cure), nevertheless strongly resists the infection. First, in many observed cases the skin has been involved continuously and extensively for many years, but the general health of the patient has not been affected. With an infection potentially so virulent as blastomycosis, we can only conclude that in these instances it is being resisted very well by other parts of the body. Second, in another manifes-

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tation of high resistance, the skin succeeds in healing itself completely, in the central portions of the usual type of chronic cutaneous blastomycosis. Third, anyone who has successfully diagnosed this type of blastomycosis by histopathologic study cannot but be deeply impressed with the difficulty of discovering the causative fungi; they are usually present in numbers so small that several sections must be examined before one organism can be seen. In contrast, the cellular reaction engendered in the skin of the host by these sparse organisms is tremendous; a dense infiltrate consisting of thousands of lymphocytes and plasma cells for every fungus cell is contained beneath an epidermis so strongly stimulated that it closely resembles a carcinoma (pseudoepitheliomatous hyperplasia). This phenomenon certainly bespeaks a high degree of resistance, indicating that the skin also participates in the immunologic reaction that previously cleared the lungs. Nevertheless, the resistance of the skin often is not completely successful. There must be some small defect in the mechanism which keeps resistance a little short of perfection. The nature of this deficiency cannot be defined at present, but it offers a promising field for research. Many discrepancies also arise from the well-established fact that blastomycin is not so specific for blastomycosis as desirable; many cross reactions occur in patients with other fungal diseases, and vice versa (Emmons, Campbell, and Binkley). Some of the confusion may be resolved in the future by better methods of preparation, selection, and standardization of antigens, but at the present time it is not possible to state whether or not blastomycosis has the same natural history as histoplasmosis and coccidioidomycosis. According to Conant (1962), much of the information concerning immunity in North American blastomycosis is fragmentary, controversial, and incomplete, but certain facts may be stated with assurance. Man is resistant to infection, as evidenced by spontaneous healing of the pulmonary disease (Kunkle et al., 1954; Smith et al., 1955) and of the infection caused by primary cutaneous inoculation (Schwarz and Baum, 1952; Wilson et al., 1955; Harrell and Curtis, 1959). Allergy is established after infection, as evidenced by the occurrence of erythema nodosum (Smith et al., 1955), and by numerous reports of the delayed tuberculin-type reaction to cutaneous injection with Blastomyces antigens. A lack of uniformly positive tests for the latter reaction in proven disease, however, prevents an accurate survey of population groups to determine the extent of past infection. This lack of uniformity may mean that blastomycosis, in contrast with coccidioidomycosis and histoplasmosis, is not a highly sensitizing disease, or that the antigens employed are not sufficiently sensitive to elicit cellular sensitivity if a low degree of allergy does follow a benign, primary, self-limited infection. In most instances of clinical disease the extent of infection seems to be paralleled by the titer of complement-fixing antibodies, as demonstrated by repeated tests: that is, the higher the titer

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the more widespread the infection. W i t h the present availability only of fungistatic rather than fungicidal drugs for the treatment of blastomycosis, a patient's immunologic response to his infection is still an extremely important factor in his ultimate recovery. THERAPY Until the recent advent of amphotericin B, the treatment of North American blastomycosis has always been uncertain, and the results have often been discouraging. Potassium iodide administration was a standard approach, but it frequently failed, even in conjunction with roentgen therapy. T h e chronic cutaneous form was often completely eradicable by surgical extirpation of all involved tissue, easily accomplished by curette and desiccation, but it was obvious that the patient's own immunologic resistance to invasion in most of his normal tissues was the explanation for the rarity of subsequent recurrence. Stilbamidine has cured many cutaneous cases, but it fails in the serious disseminated form when immunologic resistance is not present to assist it, and its toxicity for the fifth nerve is a considerable handicap. T h e vast majority of patients afflicted with coccidioidomycosis or histoplasmosis are destined to recover spontaneously, without chemical or antibiotic therapy, but such therapy is almost invariably required in cases of blastomycosis. Amphotericin B is the only drug recommended at this time, and the method of administration does not differ from that outlined above (see chap. 3). Except in very mild cases, exhibiting good skin-test reactivity and low complement-fixation titer, the total dosage should be at least 2 gm, and more if indicated and tolerated; close observation should be continued for at least two years, so that therapy may be resumed as soon as it is indicated. T h e results so far have been excellent, with perhaps 80 percent cured. Skin lesions begin to melt away within two weeks, and continue to clear with encouraging speed. Internal disease is less easily treated, but also seems to respond well. Relapses have occurred in 10 to 15 percent of the cases, some after a year of apparent recovery, indicating the need for long-term follow-up and for a conservative judgment on the ultimate reliability of amphotericin B. Most of such relapses have again been reversed by further treatment. Failures have occurred only in patients exhibiting negative or poorly reactive skin tests, high complement-fixation titers, and obviously overwhelming disease; some were practically moribund before the drug was initiated. Particularly impressive is the fact that many of the cases successfully treated with amphotericin B had previously failed to yield to stilbamidine, or had relapsed after it had been used. T h e final evaluation will need some years, but amphotericin B seems to be a tremendous improvement over all previous therapy.

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T h e chronic c u t a n e o u s f o r m of N o r t h A m e r i c a n blastomycosis m a y b e greatly benefited by curettage a n d desiccation, the i n v o l v e d tissue separati n g at a n easily defined l i n e of cleavage. I t is always difficult to k n o w , however, w h e t h e r p u l m o n a r y or disseminated lesions elsewhere i n h i d d e n areas are c o n c o m i t a n t l y present. A m p h o t e r i c i n B s h o u l d therefore be used for p e r h a p s a m o n t h , a n d surgical therapy resorted to o n l y if the response is slow. T h e d r u g s h o u l d then be c o n t i n u e d postoperatively u n t i l the prognosis seems assuredly g o o d . R e s e c t i o n of persistent c a v i t a t i o n or other p u l m o n a r y residuals m a y be i n d i c a t e d if sufficiently localized. A m p h o t e r i c i n B s h o u l d be used b o t h pre- and postoperatively to c o m b a t the surgical spreading of the infection, as w e l l as to treat o t h e r lesions that m a y exist outside the r e m o v e d p o r t i o n . Bibliography Abernathy, R. S. 1959. Clinical manifestations of pulmonary blastomycosis. Ann. Intern. Med., 51:707. Ajello, L. 1961. Isolation of Blastomyces dermatitidis from the soil. Science, 133:1126. Baum, G. L., and J. Schwarz. 1959. North American blastomycosis. Amer. J. Med. Sci., 239:661-683. Benham, R. W . 1934. Fungi of blastomycosis and coccidioidal granuloma. Arch. Dermatol. Syphil., 30:365. Blackard, C. E., and H. I. Berman. 1962. Genitourinary blastomycosis: 3 cases. J. Urol., 88:94. Carmody, E. J., and W. Tappen. 1959. Blastomycosis meningitis: report of a case successfully treated with amphotericin B. Ann. Intern. Med., 51:780. Derbes, V. J., and J. D. Krafchuk. 1958. Response of North American blastomycosis to amphotericin B. Bull. Tulane Med. Fac., 17:157. Drouhet, E., and R. Wilkinson. 1957. Activité thérapeutique de l'amphotericine B dans la blastomycose experimentale. Ann. Inst. Pasteur (Paris), 93:631. Dunn, Y. O., S. McMillen, and T . Cornbleet. 1963. Oral amphotericin B therapy in blastomycosis. Arch. Dermatol., 88:75. Gephardt, M. C., and T . J. Hanlon. Blastomycosis. Arch. Dermatol., 84:660. Gilchrist, T . C., and W. R. Stokes. 1896. T h e presence of an Oïdium in the tissues of a case of pseudo-lupus vulgaris. Bull. Johns Hopkins Hosp., 7:129-133. . 1898. A case of pseudo-lupus Vulgaris caused by Blastomyces. J. Exptl. Med., 3:53-78. Gordon, C. A., and W. B. Stewart, i960. Treatment of North American blastomycosis with amphotericin B. Canad. Med. Assoc. J., 82:471. Grandbois, J. 1963. North American blastomycosis in Canada. [In French.] Laval Med., 34:714. Greer, A. E. i960. North American blastomycosis of a nasal sinus: report of case. Diseases of the Chest, 38:454. Harrell, E. R. 1959. T h e treatment of North American blastomycosis with amphotericin B. Amer. Trudeau Soc. Meeting. Amer. Rev. Tuberc. Pulmon. Diseases, 78:312.

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Harrell, E. R., and A. C. Curtis. 1957. T h e treatment of North American blastomycosis with amphotericin B. Arch. Dermatol., 76:561. . 1959. North American blastomycosis. Amer. J. Med., 27:750. Harris, J. S., J. G. Smith, Jr., W. C. Humbert, N. F. Conant, and D. T . Smith. 1957. North American blastomycosis in an epidemic area. Public Health Repts., 72:95Hazen, E. L., and E. D. Tahler. 1951. Quantitative complement fixation tests for evidence of histoplasmosis and blastomycosis. Repts. N.Y. State Dept. Health, no. 73. Howies, J. K., and C. I. Blach. 1953. Cutaneous blastomycosis: 58 cases. J. Louisiana Med. Soc., 105:72. Kaplan, W., et al. 1963. Specific fluorescent antiglobulins for the detection and identification of Blastomyces dermatitidis yeast-phase cells. Mycopathologia, i9:i73Letterman, G. S., and M. Schurter. i960. Reconstructive surgery in the treatment of blastomycosis. Southern Med. J., 53:1217. Lieberman, A. 1963. T h e case of the fumbled fungus. J. Indiana Med. Assoc., 56:1017. McDonough, E. S., L. Ajello, R. J. Ausherman, A. Balows, J. T . McClellan, and S. A. Brinkman. 1961. Human pathogenic fungi recovered from soil in an area pathogenic for North American blastomycosis. Amer. J. Hyg., 73:75. Martin, D. S., and D. T . Smith. 1939. Blastomycosis (American blastomycosis, Gilchrist's disease). Amer. Rev. Tuberc. Pulmon. Diseases, 39:275. Procknow, J. J., and C. G. Loosli. 1958. Treatment of the deep mycosis. Arch. Intern. Med., 101:765. Schwarz, J., and G. L. Baum. 1951. Blastomycosis. Amer. J. Clin. Pathol., 21:999. . 1952. Results of skin tests in contacts of blastomycosis patients. J. Invest. Dermatol., 18:3. Seabury, J. H., and H. E. Dascomb, 1958. Experience with amphotericin B for the treatment of systemic Mycoses. Arch. Intern. Med., 102:960. Smith, D. T . 1949. Immunologic types of blastomycosis. Ann. Intern. Med., 31:463. Smith, J. G., Jr., J. S. Harris, N. F. Conant, and D. T . Smith. 1955. An epidemic of North American blastomycosis. J. Amer. Med. Assoc., 158:641. Utz, J. P., D. B. Louria, C. W. Emmons, and N. B. McCollough. 1958. A report of clinical studies on the use of amphotericin B in patients with systemic fungal diseases. Antibiot. Ann., 1957-58:65. Wilson, J. W., E. P. Cawley, F. D. Weidman, and W. S. Gilmer. 1955. Primary cutaneous North American blastomycosis. Arch. Dermatol. Syphil., 71:39.

8 South American blastomycosis (Paracoccidoidomycosis)

INTRODUCTION geographic areas, almost exclusively in South America, a species of fungus occasionally causes a highly dangerous, chronic, granulomatous disease with a distinct predilection for mucous membranes, the gastrointestinal tract, lymph nodes, skin, and lungs. Despite the geographic limitation, the disease should not be ignored by practitioners in other regions; the study of its differences from other deep mycoses may yield valuable clues leading to better understanding of the pathogenesis and immunology of all infectious diseases. IN CERTAIN

HISTORY In 1908 Lutz reported two patients who had granulomatous lesions in the mouth accompanied by an intense cervical adenopathy, from which he had obtained a fungus which reproduced in the tissues by a multiple 101

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budding process. Because of the vague resemblance of these organisms to Coccidioides immitis, Lutz called the disease pseudococcidioido granuloma. Within the next few years Carini and Splendore published several papers with detailed clinical observations and further studies of the fungus. In the many reports that followed, the disease was frequently confused with coccidioidomycosis, and several different names were given to the fungus. T h e subject was clarified by de Almeida in a series of brilliant studies, beginning in 1927, on the pathology and the mycology of the disease. T h e voluminous literature that has appeared since then includes valuable books by Fonseca, Lacaz, and Azulay; an extensive study published in 1947 under the direction of Orsini and Aleixo covers the proceedings of the Second Annual Reunion of Brazilian Dermatologists. More recently, useful contributions have been made by Lacaz and Fava-Netto, Boglioglo and Aroeira Neves, Furtado, and Sampaio. ETIOLOGY It is generally accepted that only a single fungus causes South American blastomycosis, although one rare disease usually included within its boundaries may be caused by a different genus of organism. T h e r e is still much disagreement as to the proper name for the usual fungus. Conant and Howell's (1942) designation of Blastomyces brasiliensis is often used, but most South American workers prefer Paracoccidioides brasiliensis. DISTRIBUTION South American blastomycosis is encountered principally in the Brazilian states of Sao Paulo, R i o de Janeiro, and Minas Gerais, and in the vicinity of Guanabara Bay; it also occurs frequently in Argentina and Venezuela, and sporadically in other South and Central American countries and in Mexico. Although no age group is exempt, the incidence is highest among people between twenty and fifty. Agricultural workers are particularly susceptible, and males predominate among patients, the ratios varying from 6:1 to 12:1 in different studies. N o racial hypersusceptibility is apparent. EPIDEMIOLOGY T h e habitat of the fungus that causes South American blastomycosis has never been thoroughly established in nature, although Batista has isolated it from soil. T h e clinical aspects of the disease indicate that the fungus is often acquired through the mouth, either on vegetation used by agricultural workers to clean their teeth, or on stems and leaves of various plants which they chew. T h e fungus is therefore thought to exist in na-

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ture, either as a plant parasite or in the soil. N o instances of transmission directly from man to man, or from animals to man, have been recorded. Primary inoculation into the skin may occur, but convincing evidence is difficult to obtain. T h e lungs, although affected in a high percentage of cases, are not usually regarded as the most common primary portal of entry. More recently, the prevalence of severe pulmonary involvement, with less than convincing evidence that previous oral lesions were responsible, has led to the conviction that primary invasion by means of the lungs through inhalation occurs frequently. CLINICAL

CHARACTERISTICS

O n the basis of present knowledge it is impossible to categorize South American blastomycosis under the several types used for other deep mycoses. T h e point of ingress is almost always in the mouth or nearby; the earliest lesions have often been observed in tonsils, larynx, or nose. Occasionally the anal area is affected first, and rarely the eyes. From any of these primary foci the disease is disseminated by both the hematogenous and lymphatic routes, and may eventually affect practically every organ in the body. Azulay (1950) recommended classification into only two clinical types: tegumentary for involvement of skin and mucous membranes, and extrategumentary for all other forms.

Tegumentary South American blastomycosis T h e . primary lesion is usually in the mouth, in the mucosa of cheeks, lips, gums, tongue, or palate, or in the nose, and consists of painful erythematous ulcerations which spread slowly but extensively, often to the tonsillar area. T h e bases of the ulcers have a granular appearance, with yellowish spots which Pupo called "mulberry-like erosions." T h e process often extends from the mucous membranes onto the skin. Other cutaneous lesions develop by lymphatic or hematogenous dissemination, and may be papular, pustular, tuberous, ulcerated, or vegetative and warty. T h e commonest site is the face, but any other part of the body surface may be involved.

Extrategumentary form Sooner or later the lymph nodes are almost always involved, particularly in the region draining the primary site. Sometimes dissemination occurs without the original primary lesion being discoverable. T h e r e may be enough generalized lymphadenopathy to simulate Hodgkin's disease or malignancy. Nodes that are affected tend to ulcerate and discharge onto the skin, thereby forming new centers of cutaneous spread, as in scrofuloderma. T h e lungs are affected in a high percentage of instances—up to 94 per-

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cent, in the opinion of some authors—but this fact has only recently become evident. Pulmonary infection exhibits a variable picture, but in general signs and symptoms tend to be milder than would be expected from X-ray studies or from the findings at autopsy, which may reveal large and small nodules, miliary dissemination, fibrosis, small cavities, and thickened pleurae. Lesions tend to be bilateral, and prefer the bases of the lungs, or seem to spread from the hilar regions while leaving them relatively free. Often it is difficult to differentiate the pulmonary form of the disease from tuberculosis, which is in fact frequently concurrent. At times the lower gastrointestinal tract seems to be the primary inoculation site. T h e spleen and the liver are commonly involved. Appendiceal lesions occur, and involvement of the anorectal area is not rare. There are bone lesions of osteolytic type in some cases, and occasionally the central nervous system is affected. In an unusual form of cutaneous infection which has occasionally been observed, keloidal areas develop on the back or the legs. First described by Jorge Lobo in 1931, this infection may be simply a variant of South American blastomycosis, or it may be a different disease caused by another organism. PATHOLOGY There is nothing specific about the macroscopic and microscopic changes caused in tissues by South American blastomycosis, but they resemble the changes caused by North American blastomycosis more closely than those caused by any other mycosis. Histopathologically, granulomatous areas, of either the tuberculoid or the foreign-body type, are seen, but it is necessary to find and identify the causative organism before the diagnosis can be made. Skin lesions show ulceration, microabscesses, and pseudoepitheliomatous hyperplasia. Abscesses in the dermis are filled principally with polymorphonuclear neutrophiles, but lymphocytes, plasma cells, and eosinophiles are present in smaller numbers. T h e causative organisms may be seen in microabscesses, or within giant cells. T h e granuloma may be predominantly of the tuberculoid type or it may be markedly inflammatory; in fact, areas of both types may exist in close proximity, suggestive of the picture so often seen in coccidioidomycosis. T h e fungus is seen as thick-walled parent spherules from 10 to 60 microns in diameter, producing buds either singly or in multiples. Round, oval, or pyriform buds, varying from 2 to 10 microns in diameter, may be seen on a single cell, and occasionally thirty or forty are studded all over the surface. In sections these large cells are seen cut transversely, and, with the peripheral buds, show a picture characteristic of this fungus alone, vaguely resembling a marine pilot's wheel. The buds are capable of independent life when still small, and, in contrast with Blastomyces

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dermatitidis, are separated frequently from the parent cell in that condition. When only one bud is being produced, it may be impossible to differentiate the organism from B. dermatitidis, and more characteristic multiple-budding forms must be sought. They are more likely to be found in lymph glands or visceral organs than in the skin or mucous membranes. T h e cell walls do not stain well with H 8c E, but the cytoplasm, both of the mother cell and of the daughter buds, takes on a deep blue. T h e PAS stain serves very well in making the search easier. In contrast with North American blastomycosis and coccidioidomycosis, the lower intestinal tract is frequently affected in South American blastomycosis; the lesions seem to originate in the lymphoid tissue of the mucous membrane, causing focal necrosis. In disseminated disease lesions develop in most organs, particularly spleen, liver, pancreas, kidneys, adrenals, and heart; granulomatous osteomyelitis and bone destructive processes are also characteristic. In Jorge Lobo's disease the keloidal outgrowths are extremely firm fibrotic masses where very large numbers of fungus cells are seen with almost no inflammatory reaction. This disease presents many features that cannot adequately be explained by our present theories; nor will they be understood in the future unless or until the causative organism is successfully cultured and can be studied mycologically and immunologically. As has been intimated, the disease may be an entirely different one, caused by a different fungus. MYCOLOGY It is generally agreed that (with the possible exception of Jorge Lobo's disease) South American blastomycosis is caused by a single species of fungus, but there is no consensus as to its taxonomic position botanically. T h e most widely accepted name among South American workers is Paracoccidioides brasiliensis (Splendore) Almeida 1930, although Lutziomyces histo-sporo-cellularis is preferred by some in honor of Lutz, who discovered the disease. Conant and Howell (1942) believed the fungus had enough similarities with Blastomyces dermatitidis to warrant its inclusion in the same genus, calling it thus Blastomyces brasiliensis, but the most experienced researchers remain unconvinced. Aroeira Neves and Boglioglo (1951), impressed by the nature of the conidia produced on the aerial hyphae in room-temperature cultures, which they considered to be aleuriospores, called the organism Aleurisma, retaining the species epithet of brasiliensis. As noted above, in infected animal tissues the fungus grows as thickwalled spherules producing single or multiple buds, with narrow necks (in contrast with B. dermatitidis). Material obtained from lesions should be inoculated into Sabouraud's

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glucose agar, as well as that containing added blood or other enrichment. Duplicate specimens must be kept in the incubator and at room temperature. At incubator temperature the method of reproduction is the same as in animal tissues, with only rarely a brief, abortive attempt to form a hyphal thread. Grossly these colonies appear waxy or yeastlike, and are usually white to cream-colored. Microscopically, large numbers of budding cells are seen to be massed together; no cross walls are developed with any regularity between mother and daughter cells before the latter take up reproduction on their own. At lower temperatures growth occurs only by the formation of mycelial hyphae, giving a moldy, fluffy culture, white at first and later often becoming a dirty, light yellowish-brown. Microscopic examination reveals hyphal threads, branched and septate with'intercalary or terminal chlamydospores. Rounded, ovoid, or pear-shaped conidia are borne singly on short conidiophores or along the sides of hyphae in the manner suggestive of Blastomyces dermatitidis, but they tend to remain attached even when the hyphae have become dead and empty, in contrast with true conidia; it was this characteristic that led Aroeira Neves and Boglioglo to class the conidia as aleurospores. Neither de Almeida nor Conant was convinced by this evidence. Intraperitoneal injection into mice produces lesions in liver, spleen, and mesentery, which tend to involute spontaneously after a while. Intratesticular inoculation into guinea pigs produces only a localized infection. The fungus causing Jorge Lobo's disease has never been isolated in artificial culture, even though it exists in large numbers in the tissues. It does not produce multiple buds, and eventually will probably be established as a different fungus. It has been named Glenospora loboi or Loboa loboi. IMMUNOLOGY Most patients diagnosed as having South American blastomycosis show poor immunologic resistance to the disease. It has not yet been conclusively demonstrated that the disease exists in a mild, asymptomatic form clearing spontaneously with subsequent immunity in numerous persons living in endemic areas, as do coccidioidomycosis and histoplasmosis, but recent skin testing of normal persons with a polysaccharide derivative of cultures of the fungus has revealed suggestive percentages of positive reactors, particularly among relatives of patients afflicted by the disease. It seems likely, then, that the pattern of these other mycoses may actually be followed. The most thoroughly investigated material for serologic testing is the lutziomycin developed by Fava-Netto, which is a purified polysaccharide obtained by a modification of Norden's technique. Both complementfixation and precipitin reactions are consistently obtained in high percentages of patients afflicted with the disease. Antibodies revealed by

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precipitin testing are the first to appear and the first to disappear, particularly after treatment; but they tend to lessen after a year without regard to the clinical course. This reaction often increases after treatment is stopped, when the disease is again becoming active. Complement fixation occurs in almost all severe cases, but appears later and never in the high titer so common in comparable stages of coccidioidomycosis. W e have suggested that this result may be owing to the antigen's having been too highly purified; if coccidioidin were treated so drastically in its preparation as is Fava-Netto's purified polysaccharide, its ability to fix complement would be markedly impaired. Although these reactions are not identical with those obtained in coccidioidomycosis, they do conform, at least roughly, to the same pattern. In fact, the degree of conformity is surprising in view of the differences in the fungi and in the clinical forms produced by the two diseases, suggesting that the basic mechanisms of the immunologic response may be the same. THERAPY Prior to 1940 South American blastomycosis was almost uniformly fatal within a few months or years. Sulfonamide therapy considerably improved this outlook, and many patients cleared satisfactorily. It soon became evident, however, that relapses were common, and it was decided that the drugs were not lethal to the fungus, but were merely inhibitory in varying degrees. It has always been difficult to know when all lesions have healed, leading to uncertainty as to whether or not some of the relapses were in fact newly acquired reinfections. T h e sulfonamides do not change the immunologic status of the patient, but leave him just as susceptible as before. For these reasons a great many patients were never able to discontinue treatment permanently, and many were known to have been taking the drugs for ten years or more. According to Sampaio, 43 percent of 338 patients treated with sulfonamides between 1947 and 1958 died, and most of the survivors still had active disease. Many instances of acquired microbial resistances to sulfonamides are known. Sulfadiazine has probably been the most widely used sulfonamide, but various others, sometimes in combination, have been recommended. T h e parent compound, sulfanilamide, and the sulfones are said to be ineffective. Sulfamethoxypyridazine is preferred by Padilha-Gon9alves (1962). From 2 to 4 gm is the recommended daily dosage for periods of not less than a month each, and often much longer, before rest intervals of two weeks are begun. A t least two years of such treatment is advised, and the period is often extended. Reports indicate that amphotericin B is also very effective against South American blastomycosis, and that it is likely to become widely accepted as the preferred drug. Sampaio (i960) reported that fifty-eight of sixty-one cases

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were cleared promptly and completely by its use; of the patients, thirty-two had previously been classed as sulfonamide-resistant. T h e few patients who relapsed showed a good response again to amphotericin B. Acquired microbial resistance was not observed. Dosages up to a .mg/kg, and totaling up to 8,500 mg, were employed in the manner outlined above (see chap. 3). Corticosteroids were simultaneously administered to prevent side effects, and no interference with the clinical response to the drug or apparently with immunologic processes was observed. Past disappointments have made those who have had long experience with this disease wary of early enthusiasm. Sampaio considers amphotericin B "effective, and the drug of choice in severe and extensive forms, in sulfa-resistant cases or where rapid clinical improvement is desired." Padilha-Gon^alves (1962) also considers the drug effective, but believes it to be more toxic and less well tolerated than sulfonamides; during the necessarily more frequent periods of discontinuance, he suggests sulfonamide therapy. Amphotericin B also necessitates hospitalization for administration by slow intravenous drip, in contrast with oral administration of sulfonamides on an ambulatory basis. Negroni's cases cleared well on amphotericin B, but the fact that the patients were subsequently kept on sulfonamides for long periods indicates his lack of confidence. It has been emphasized by all workers that it is much too early to evaluate conclusively the effectiveness of amphotericin B, but the drug appears to be very promising.

Bibliography A l m e i d a , F. P. de. 1929. Comparative study of coccidioidal granuloma in the U n i t e d States and Brazil. [In Portuguese.] A n . Fac. M e d . U n i v . Sao Paulo, 4:91. . 1930a. Comparative study of coccidioidal granuloma in the U n i t e d States a n d Brazil, establishing a new genus for the Brazilian parasite. [In Portuguese.] A n . Fac. M e d . U n i v . Sao Paulo, 5:125. . 1930b. Differential features of the etiologic agents of coccidioidal granuloma of the U n i t e d States and Brazil. [In French.] C o m p t . R e n d . Soc. Biol., 105:315-316. .

1933.

Blastomycose

em

geral

e sua classificacao:

definicao

e

classifi-

cacao des blastomycoses. R e v . Asoc. Paulista Med., 3:270. A l m e i d a , F. P. de, C . d a S. Lacaz, a n d A . C . Cardoso C u n h a . 1945. Intradermo reacao para o diagnostico de blastomicose sul-americana granulomatose

para-

coccidioidica. Brasil. Med., 35:81. Aroeira Neves, J., a n d L . Boglioglo. 1951. Researches o n the etiological agents of the A m e r i c a n blastomycosis. Mycopathol. Mycol. A p p l . , 5:133. Azulay, R . D . 1950. Contribuicao ao estudo da micose de Lutz. Thesis. R i o de Janeiro: Grafica Olimpica. B e n a i m Pinto, H .

1961. Paracoccidioidosis as a systemic disease. [In

Mycopathologia, 15:90.

Spanish.]

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Boglioglo, L. 1950a. About the morphology and mode of reproduction of "Aleurisma brasiliensis" Aroeira Neves and Boglioglo, 1950, in human tissues. Rev. Asoc. Med., 1:253. . 19506. South American blastomycosis (Lutz's disease): a contribution to knowledge of its pathogenesis. Arch. Dermatol. Syphil., 61:470. Conant, N. F., and A. Howell, J r . 1942. T h e similarity of the fungi causing South American blastomycosis (paracoccidioidal granuloma) and North American blastomycosis (Gilchrist's disease). J . Invest. Dermatol., 5:353-370. Fava-Netto, C., T . de Brito, and C. da S. Lacaz. 1961. Experimental South American blastomycosis of the guinea pig: immunologic and pathologic study. Pathol. Microbiol. (Basel), 24:192. Fava-Netto, C., and A. Raphael. 1961. Intradermal reaction with Paracoccidioides brasiliensis polysaccharide in South American blastomycosis. [In Portuguese.] Rev. Inst. Med. Trop. (Sao Paulo), 3 : 1 6 1 . Furtado, T . A. 1963. Mechanism of infection in South American blastomycosis. [In Portuguese.] Dermatol. Trop., 2 (J an .-March): 2 7. Furtado, T . A., et al. 1959. Tratamento da blastomicose sul-americana pela anfotericina B. Hospital (Rio), 56:1001. Furtado, T . A., J . W. Wilson, and O. A. Plunkett. 1954. South American blastomycosis (paracoccidioidomycosis). Arch. Dermatol. Syphil., 70:166. Lacaz, C. da S., R . G. Ferri, C. Fava-Netto, and E. Belfort. 1962. Immunochemical aspects of South American blastomycosis and Jorge Lobo's disease. [In Portugese.] Med. Cirurg. Farmacol., 298:63. Lacaz, C. da S., and S. de A. P. Sampaio. 1958. Tratamento da blastomicose sulamericana com anfotericina B. Rev. Asoc. Paulista Med., 52:443. Lutz, A. 1908. Uma mycose pseudococcidica localizada na boca e observada no Brasil: contribuicao ao conhecimento das hyphoblastomycoses americanas. Brasil-m£d., 2 2 : 1 2 1 . Machada Filho, J., and J . L . Miranda, i960. Considerations on South American blastomycosis: the pulmonary involvement in 338 cases. [In Portuguese.] Hospital (Rio), 58:431. Machado Filho, J . , J . L . Miranda, and E. Monteiro. 1961. On the electrophoretic patterns of the serum proteins in 220 cases of South American blastomycosis. [In Portuguese.] Hospital (Rio), 60:811. MacKinnon, J . E. 1958. Amphotericin B en la blastomicosis sud-americana experimental. An. Fac. Med., Montevideo, 43:201. MacKinnon, J . E., I. A. Conti-Diaz, L. A. Yarzaballa, and N. Tavella. i960. Environmental temperature in South American blastomycosis. [In Spanish.] An. Fac. Med. Montevideo, 45:310. Michelany, J., and B. Lagonegro. 1963. Asteroid bodies in Jorge Lobo's disease. [In Portuguese.] Rev. Inst. Med. Trop. (Sao Paulo), 5:33. Miranda, J . L., and J . Machado Filho. 1959. Consideracoes em torno da blastomicose sul-americana: sobre a acao da amphotericina B. Hospital (Rio), 56:93. Miranda, J . L., J . Machado Filho, and E. Monteiro. 1960. Considerations on South American blastomycosis: the behavior of C reactive protein. [In Portuguese.] Hospital (Rio), 58:251. Moraes, M. A. 1962. Jorge Lobo's type of blastomycosis: six new cases discovered in the state of Amazonas (Brazil). [In Portuguese.] Rev. Inst. Med. Trop. (Sao Paulo), 4:187.

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Moraes, M. A., and W. R. Oliveira. 1962. Recent cases of Jorge Lobo's mycosis discovered in Manaus, Amazonas (Brazil). [In Portuguese.] Rev. Inst. Med. Trop. (Sao Paulo), 4:403. Padilha-Gon^alves, A. 1962. Treatment of south American blastomycosis. [In Spanish.] Arch. Argentin. Dermatol., 12:231. Padilha-Gongalves, A., and C. Bady. 1946. Aspectos clinicos radiologicos da blastomicose brasileira pulmonar. Hospital (Rio), 30:1021. Sampaio, S. de A. P. i960. Tratamento da blastomicose sul-americana com anfotericina B. Unpublished Thesis. Sao Paulo. Splendore, A. 1909. Sobre um novo caso de blastomycose generalizada. Rev. Soc. Sci. (Sao Paulo), 4:52. . 1912. Un affezione micotica con localizzazione nella mucosa della boca osservata en Brasile, determinata da funghi appartenenti alla tribù degli Exoascei (Zymonema brasiliense n. sp.). Rome: Tipografia Nazionale di G. Bertero. Veronesi, R., et al. 1959. Resultados terapeuticos obtidos com a emprego da amphotericina B em formas superficiais e profundas da blastomicose sul-americana. Rev. Hosp. Clin., 14:231.

9 Cryptococcosis

INTRODUCTION species of fungus, Cryptococcus neoformans, occasionally causes in human beings a chronic, wasting, highly dangerous infection called cryptococcosis or torulosis. T h e disease shows a predilection for the central nervous system, but may also affect skin, bones, and viscera. It is probably more common than is usually recognized, the diagnosis being missed because of a low index of suspicion and the difficulty of proving its presence. A SINGLE

HISTORY In 1894 Busse reported the case of a woman with skin and bone lesions caused by a yeastlike fungus, upon which Buschke elaborated in 1895. A few probable cases were reported in succeeding years until 1914, when Verse presented a carefully studied and proved instance. Stoddard and 111

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Cutler (1916) published a clear delineation of the pathology, describing the clinical picture sufficiently to differentiate the disease from the other deep mycoses. Monographs were contributed by Freeman in 1931, C o x and Tolhurst (1946), and Littman and Zimmerman (1956). Louria's recent studies have been valuable. In 1935 Benham and de Almeida clarified the earlier confusion of this fungus with other yeastlike pathogenic fungi. ETIOLOGY Cryptococcosis is caused by Cryptococcus neoformans, usually considered a single species of fungus, although there are substantial differences among strains of the organism. DISTRIBUTION Although cryptococcosis was called European blastomycosis for years, it actually has no geographic limitations; it simply seems to occur more frequently in some regions than in others because of better diagnostic facilities and personnel. In this respect it resembles actinomycosis, sporotrichosis, and nocardiosis, and its distribution suggests rather strongly either that the infection may be endogenous in nature or that the fungus is distributed widely over the world somewhere in nature. It is also possible that variations in the host rather than in the fungus determine whether or not infection will occur. N o age group is exempt from cryptococcosis, but it more commonly afflicts people from forty to sixty years old. T h e r e is no prevalence owing to race or color. Males predominate over females about 2 to 1. EPIDEMIOLOGY Cryptococcosis is not a common disease, which at first glance suggests that the causative fungus is only occasionally encountered by man. O n the contrary, it is likely that Cryptococcus neoformans is present in or on the bodies of most persons at some time or times during their lives. It has long been known that the organism has been cultured from normal skin and mucous membrane (Benham, 1935); it has been recovered from fermenting fruit juices (San Felice, 1894), from soil (Emmons, 1951), and from milk (Klein; Carter and Young, 1950). Many of the strains so obtained exhibited a degree of virulence for laboratory animals equal to that of the organisms obtained from fatal human cases. Distribution of the fungus is apparently worldwide, for the disease is encountered without geographic limitations. Cryptococcosis also occurs in animals by natural means, but there has been no instance reported of a human infection derived from an animal, nor of transmission from man to man. T w o discoveries by Emmons have now greatly clarified this subject. In

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1950 he succeeded in isolating C. neoformans from soil, and further pinpointed the source in 1955 by discovering that it is frequently saprophytically associated with pigeon droppings, under their roosting sites in upper floors of buildings, in towers, and on window ledges in cities, and in stables and haymows in rural areas. Man and animals must frequently acquire these fungi by inhalation of dust containing the spores. Some of the epidemics of respiratory infections which have occurred by exposure to dust where pigeons have been present and which were classed as histoplasmosis because of skin and serologic tests, without cultural proof, may well have been cryptococcosis. Although apparently virulent strains have been isolated from healthy human beings, this result is not common enough to entertain the opinion that the infection is often endogenously acquired, as previously believed. There is, however, no lack of opportunity to contact the causative organism, and the rarity of the disease can be explained only on the basis of the ability of the animal body completely to resist the initial invasion, except under unusual circumstances. Such resistance may result, as it does in coccidioidomycosis and histoplasmosis, from the ability of almost all persons to develop quickly a high degree of specific immunological resistance in response to the infection. But there is as yet no evidence for this ability in cryptococcosis, as a specific skin test that could reveal its presence is lacking. It is more likely that something must happen (as, for example, with staphylococci and streptococci) to lower the natural barriers of resistance, either locally or systemically, before infection can occur. T h e factors of concomitant trauma and symbiotic alliance with bacteria, which are important in actinomycosis, do not seem to apply to cryptococcosis. There is, however, an association of statistical significance with lymphoblastomas, most often Hodgkin's disease and leukemia. Sarcoidosis has also been associated in some cases, as have rheumatoid arthritis, infective hepatitis, rheumatic heart disease, and silicosis, as reported by Utz (1962), as well as diabetes (often subclinical), in eight of thirty instances. More than a third of Utz's cases had been given corticosteroids for their underlying disease, and it is significant that these materials almost certainly lower immunologic resistance to other fungal diseases to a harmful degree. Cryptococcosis is nearly always acquired by the inhalation of spores of the fungus along with terrestrial dust. Direct inoculation through the skin has been accepted as the portal of entry by some authors when reporting cases, but features that make this conclusion doubtful have usually been cited. Apparently the portal has sometimes been the oropharynx or the gastrointestinal tract. Cryptococcus neoformans has been cultured from the blood of infected persons, indicating the possibility of hematogenous dissemination. In laboratory animals lymphatic spread has been observed, but not as yet in human beings. Semerak suggests that meningitis may occur by direct spread of the fungus from the nasopharynx.

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T h e systemic mycoses CLINICAL

CHARACTERISTICS

It is not possible to divide cryptococcosis into clinical syndromes, as has been attempted for other deep mycoses. Although it has been implied that a primary cutaneous form may occur, proof is lacking. Certainly the chancriform syndrome, so spectacular in some of the other diseases, has never been described. It is, however, almost certain that the chancriform picture occurs only because the patient is actively resisting the infection intensely by cellular and immunologic means, and this type of defense is usually lacking in cryptococcosis. Thus, even if the skin were to be directly inoculated with C. neoformans and disease produced, the localized chancriform syndrome probably would not occur; there might be no evidence whatever at the site. Cryptococcus neoformans is best known for its predilection for the central nervous system, but this phase does not always develop. Although Semerak suggested that infection can occur by direct spread to the meninges from the nasopharynx, it seems much more plausible that it is brought to that area from a different primary focus. Even more frequently the lungs are involved, and appear to be the most logical portal of entry, especially since the recent discovery of this fungus in dust subject to inhalation. Primary pulmonary cryptococcosis Thus far it has not been suggested that a primary pulmonary form of cryptococcosis can be differentiated from a disseminated type, unless extrapulmonary lesions have developed. T h e clinical picture of pulmonary cryptococcosis is similar to that of other chronic lung infections, except that there are frequently fewer symptoms than the extent of the disease, as revealed by physical signs or by radiography, would indicate. Fever is usually mild, and often absent. Coughing and sputum production are not prominent. Pleural pain is encountered occasionally, and effusion, rarely. Physical examination usually reveals dullness and diminished breath sounds, but rales and rhonchi are rare because there is little exudation into the bronchial tree. X-ray studies yield a wide variety of pictures, from that of mild bronchitis to large dense shadows, with either distinctly or poorly defined borders, suggesting neoplasm or abscess. There may be accentuation of the linear markings, surrounded by woolly shadows. Small nodules suggesting miliary tuberculosis or sarcoid may be seen, although in contrast with these disorders the bases of the lungs are more likely to be involved. Cavitation occurs only rarely. T h e mediastinum is usually spared, in contrast with other deep fungous diseases. T h e majority of cases exhibit bilateral involvement.

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Fig. 6. Cryptococcosis: consolidation in lung. Large, well-defined, somewhat lobulated consolidation in left lung.

In some cases the pulmonary disease itself may increase sufficiently to cause death, but more often dissemination to the central nervous system or to other organs occurs. Some cases of pulmonary cryptococcosis have apparently recovered, leading Stoddard and Cutler (1916), Sheppe, and others to speculate that there may be a fairly strong tendency toward healing in the primary pulmonary form. Some lesions become encapsulated, forming a cryptococcoma. Because cryptococcosis is thought to be rare, it is seldom seriously considered as a diagnosis in a lung disease unless accompanied by central nervous system signs or symptoms, or those referable to other organs. It is therefore entirely possible that cryptococcosis occurs frequently, and heals without recognition, as is known to be true

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Fig. 7. Cryptococcosis: extensive destruction of right lung. Abscess formation and empyema caused by tuberculosis in patient with cryptococcosis of bone.

of some other deep mycoses, notably coccidioidomycosis and histoplasmosis. Disseminated cryptococcosis T h e remarkable predilection of cryptococcosis for the central nervous system is well known. T h e symptoms and signs of invasion are usually referable to increased intracranial pressure, but sometimes to a meningitis less inflammatory than is usual with other microbial infections. Headache often appears early; it is intermittent and frontal at first, but later becomes jnore severe, persistent, and generalized. Occasionally the onset is sudden

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and violent, accompanied by projectile vomiting, suggesting subarachnoid hemorrhage. Dizziness, vertigo, and nuchal rigidity soon appear. Eye signs often occur, including amblyopia, diplopia, nystagmus, and ptosis. Periods of restlessness, disorientation, and hallucinations alternate with depression and loss of affect, sometimes simulating a definite psychosis, especially if the characteristic headache of cryptococcosis has not yet appeared. Epileptiform seizures occur occasionally. Papilledema from increased intracranial pressure may cause permanent optic atrophy, unless relieved frequently by spinal or cisternal tappings. Of special importance is the tendency for this disease to be accompanied by only a mild degree of inflammation, while one or more large spaceconsuming accumulations of diseased tissue develop. T h i s picture may closely simulate neoplasm, and not infrequently the diagnosis of cryptococcosis has been made by surgery directed toward the removal of tumors. As focal lesions may occur anywhere in the central nervous system, the resulting signs and symptoms are equally variable, and cannot be discussed here. Frequently, although not invariably, the cerebrospinal fluid furnishes evidence leading to the diagnosis. Pressure is usually increased; the fluid is discolored to a dirty yellow; the cell count is raised and is predominantly lymphocytic; the protein is increased and the sugar is diminished. A pellicle usually forms after the specimen of fluid has been standing for some hours, as in tuberculosis. T h e colloidal curve may be normal or of the meningitic type. T h e characteristic singly budding cells of Cryptococcus neoformans may often be seen by direct microscopic examination of centrifuged fluid, especially if India ink is added to the specimen to provide the contrast necessary to visualize the translucent capsules. T h e fungus is easily recovered and identified by culture on Sabouraud's medium at room temperature. Without laboratory confirmation of the fungous nature of the disease, the entire picture may simulate mildly inflammatory tuberculous meningitis. Undoubtedly this diagnosis has been erroneously made on many occasions. Although there may be short remissions, without definitive treatment the disease progresses slowly to death, usually within a few months; there is no recorded case in which spontaneous recovery ensued after the diagnosis was definitely established. But it is entirely possible, and even considered likely by some authors, that cases of mild infection may occur and become healed without the disease having been recognized. There is enlargement of the lymph nodes, spleen, and liver in about one-fifth of the cases of cryptococcosis, frequently simulating Hodgkin's disease or one of the other lymphoblastomas. Infection of the skin or mucous membrances occurs only in about 5 percent of the cases of cryptococcosis, most frequently as an eruption on the face consisting of translucent papules; these suggest early vesicle formation, sometimes simulating

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basal cell carcinoma, except that the border is sloping instead of abrupt. Although sometimes termed acneform, these lesions do not become truly pustular; instead their apices become necrotic and discharge a tenacious, translucent grayish or brownish-red material, consisting almost entirely of the encapsulated budding fungus cells with little or no contribution of purulent cells from the host. Such lesions as these may heal, and are not so important prognostically as is central nervous system involvement, even though they do indicate dissemination. Castellani (1963) reported two cases of chronic ulcerative balanoposthitis apparently caused by a species of Cryptococcus which failed to ferment any sugar, and to which he therefore gave a new species name, C. genitalis. Multiple, widely disseminated lesions in bone occur in somewhat less than 10 percent of the cases, according to Collins (1950), producing osteolytic rarefactions, especially in bony prominences, and suggesting coccidioidomycosis or sarcoidosis rather than the proliferative changes of tuberculosis or actinomycosis. Lesions have also been reported in heart, kidneys, adrenals, pancreas, testes, bone marrow, and great blood vessels. PATHOLOGY

Lesions of cryptococcosis are usually characterized by a startling mildness of the host's inflammatory response to the invading fungi; sometimes there is none at all, especially in brain involvement. In histopathologic study this feature is revealed by an almost complete absence of cellular infiltrate in or around the masses of fungus cells, which accordingly appear almost as though in pure culture. A thin mantle of lymphocytes may be seen at the periphery. These masses constitute the so-called gelatinous tumors which, by their enlargement, exert enough pressure on the surrounding tissues simply to push them aside, a process earlier thought to be histolytic and thus responsible for an earlier name for the fungus (Torula histolytica). Large gelatinous cysts of this type, several centimeters in diameter, are frequently found in the lungs. In the central nervous system the subarachnoid space is often distended by similar gelitinous material resembling tiny soap bubbles, particularly over the base of the brain and in the region of the cerebellum, and cystic masses occur in the gray matter, sometimes near the surface, or deep in the region of the basal ganglia or the pons. T h e spinal meninges are often involved, but rarely the cord itself. Some cases exhibit a fibrotic reaction around the lesions, indicating that some healing may take place. In such cases there is a heavy chronic inflammatory lymphocytic infiltrate, in some areas granulomatous and tuberculoid. T h e walls of residual cryptococcomas are not so thick as those of tuberculomas or histoplasmomas. Histopathologically, the fungus cells are seen mostly in small, individ-

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Fig. 8. Cryptococcosis of tibia. Well-defined bone abscess in diapkysis of tibia containing a sequestrum, with little reactive sclerosis.

ual, roughly circular, clear spaces, formerly thought to be owing to the histolytic ability of the organism, but now known to result from the presence of the characteristic capsules. T h e capsular substance is itself either dissolved away during the process of fixation, embedding, sectioning, and staining, or is converted into a few shrunken strands radiating outward from the spherules. When such strands are not present, the fungus cells do not always remain in the center of these spaces, but may be found nearer the periphery all in one direction, having thus sunk by

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gravity at some immobile unsolidified stage in the process of preparation. The cells themselves are oval or rounded and thick-walled. They take partially the basic color of H 8c E, but stain well with the PAS, the Gridley, or the Gomori method. T h e spherules reproduce entirely by the production of a single daughter cell at a time, thin-walled at first and joined to the parent cell by a thin narrow neck (in contrast with Blastomyces dermatitidis). Even though this process goes on continually and rapidly, it is evident that only some of the cells are actively budding at the time the specimen is obtained, and a very small percentage of these are cut by the microtome in the exact plane of the combination of mother cell and daughter cell, so that it is not easy to find typical budding examples quickly. DIFFERENTIAL

DIAGNOSIS

Pulmonary cryptococcosis must be differentiated from a wide variety of other pulmonary disorders. Helpful signs are the lower, or absent, febrile response, and the negative reaction to tests that are specific for many of the others. Cryptococcic meningitis may resemble tuberculous meningitis, but is usually more chronic and less inflammatory. Special attention must be given to the spinal fluid, for without microscopic search for organisms or culture it can mimic that from tuberculous meningitis. Chemically, it usually shows reduced chloride and sugar, but increased protein. T h e cell count is usually low. Skin lesions are marked by the absence of inflammatory infiltrate or pain, and the organisms are easily discovered in smears. Cryptococcosis may mimic almost any type of tumor in the central nervous system. MYCOLOGY Only one species of fungus causes cryptococcosis. Although there has been some disagreement over its botanical classification, Cryptococcus neoformans is well established as its designation. Originally believed to be able to lyse the tissues where it desired room to grow, it was called by the species name, histolytica, but this belief was long ago proved erroneous. T h e previously popular generic name Torula is botanically incorrect. Cryptococcus neoformans has only one method of reproduction: a single bud is produced from each parent spherule, separated by an elongated thin neck until mature. In culture an occasional spherule attempts to produce a hyphal strand. A short abortive cylindrical protrusion is the maximum ever accomplished, but this characteristic tends to prove the fungal ancestry of the organism. In the direct microscopic examination of sputum, spinal fluid, urine, or material taken from actual lesions, it is advantageous to mix the speci-

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men with an equal quantity of undiluted India ink. T h e granules of this material, as well as host cells and other debris, are prevented from coming close to the spherules by their gelatinous capsules, otherwise so transparent as to be invisible; thus the cells are brought out clearly and are easily discovered, and it becomes obvious at once that one is dealing with none of the other spherule-producing nonencapsulated pathogenic fungi. Not all cells produce capsules, and the mantle varies in thickness, but averages 10 to 20 microns. T h e cells themselves vary between 6 and 20 microns in diameter. As the organisms may not be present in large numbers in the cerebrospinal fluid, it is advisable to centrifuge it before adding the ink. Cryptococcus neoformans usually is easily recovered in culture on Sabouraud's glucose agar maintained at room temperature, but duplicates should be given added blood or brain-heart infusion and incubated to obviate occasional failures. As the material from lesions usually has few contaminating bacteria to compete against, antibiotics are unnecessary. Actidione, which inhibits the growth of this fungus, must be avoided. T h e colony grows slowly and remains moist and shiny, sometimes being semifluid and flowing somewhat because of gravity. It is white at first, but most strains gradually become yellow, cream-colored, or light orange. Microscopic examination reveals the characteristic singly budding cells previously described, not all of which exhibit the distinctive capsules. C. neoformans is not a true yeast, lacking the ability to produce the perfect sexual stage of the ascus. Nonpathogenic strains usually fail to grow at 37°C, but some of them can do so. Differentiation often needs other reactions, such as the organism's inability to assimilate nitrate, lactose, and melibiose, though it can utilize glucose and galactose, and proof of its pathogenicity for laboratory animals. Mice usually serve for animal studies. T h e inoculation, best made intracerebrally, causes death in from two to ten days. T h e gelatinous material recovered from the surface of the brain at autopsy is first mixed with India ink and then examined microscopically. IMMUNOLOGY It has often been stated that Cryptococcus neoformans is "poorly antigenic" to explain the fact that the skin-testing, complement-fixation, precipitation, and agglutination procedures so valuable in other deep mycoses have never been well developed for cryptococcosis. Despite a few reports of positive reactions to intracutaneous injection of extracts of cultures (Berghausen, Kessel, and Holtzwart), and at least one report of success with complement fixation (Rappaport and Kaplan), in general there has been no success. Evans and Mehl (1951) produced three polysaccharides from capsular material, and showed them to be specific for each type.

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However, there seems to be an even more logical reason for these poor results. In most cases of cryptococcosis it has been strikingly evident that the human body was making almost no effort to resist the disease, either by immunologic mechanisms or by cellular infiltration. This fact, in conjunction with the knowledge that the causative fungi are encountered with great frequency by many persons, makes it very difficult to account for the rarity of the infection. As with other deep mycoses, it must be considered possible that the size of the original inoculum is the all-important feature. Certainly mice are uniformly killed by the usual laboratory procedure of intraperitoneal or intracerebral inoculations of Cryptococcus neorformans, whereas they apparently are not fatally infected very often when they undoubtedly contact the same organism in their natural environment. It would be interesting to know if tiny amounts could be injected intraperitoneally without fatalities. On the other hand, it seems more probable that normal persons resist the fungus so completely as never to allow a lesion to develop; in other words, only individuals who are abnormal in some important phase of immunologic resistance can acquire the disease. In 1964 Halde reported that a finger had been inoculated with virulent culture material without infection resulting. A somewhat similar theory is held with regard to coccidioidomycosis, but in that instance it is believed that only persons who possess an inherent defect in their immunologic mechanisms fail to fight the disease quickly and successfully by developing a specific form of resistance not present at the time of the invasion, and thus subsequently allow it to proceed to the serious, granulomatous, disseminated form. A similar pattern has been postulated for histoplasmosis and blastomycosis. It is of course possible that pulmonary cryptococcosis occurs in large numbers of persons in a form so mild that it has not yet been recognized, and that it leaves them immune to repetition of the infection. Our knowledge of this same stage in coccidioidomycosis and histoplasmosis has been derived largely from the application of their respective skin tests to large masses of normal persons; in cryptococcosis such skin tests have not yet been extensively undertaken, apparently because most workers have concluded that the antigens so far obtained were impotent. Too little information is at hand to permit more than mere speculation, but it seems at least possible that this interpretation is analagous to that held by early workers with coccidioidin; they similarly decided that the skin test was valueless, because it gave negative reactions in most serious cases of proved coccidioidomycosis. As was later learned, the test was always right, and only the observer's interpretation was wrong, because patients tend to become nonreactive to coccidioidin as a fatal termination approaches. Because virtually all cases of proved cryptococcosis proceed to death without chemotherapy, why should we be critical of a specific skin test that yields only negative results? In fact, the negative result is the only one that would be consistent with our experience in the other deep

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mycoses, in which anergy to intracutaneously injected specific antigens is practically the rule in fatal cases. T h u s intracutaneous testing, as heretofore carried out almost exclusively on proved cases of severe cryptococcosis, may have been performing its duty with great accuracy, instead of deserving to be classed as worthless. T h e true status of this procedure cannot be known until large numbers of normal persons are tested with similar material, or at least until some are tested w h o are known to have recovered spontaneously from cryptococcosis by their own immunologic abilities alone (that is, without having to credit the response entirely to chemotherapy). T h e capsular substance of Cryptococcus neoformans is almost entirely polysaccharide. A s the ability to serve as specific skin-testing material in coccidioidomycosis, histoplasmosis, blastomycosis, and sporotrichosis resides apparently in the polysaccharide part of the material derived from cultures of the corresponding fungi, perhaps the "torulins" of Evans and Mehl (1951) may prove to be ideal for intradermal testing in cryptococcosis. Some evidence derived from animal experimentation, however, casts doubt on this idea. Kligman (1947) failed to demonstrate any reactivity to intradermal testing in infected rabbits or mice. T h e i r failure to react might still be explainable if they were fatally involved, and hence in the anergic stage. Several authors have reported inability to obtain any fixation of complement using serum from patients afflicted with cryptococcosis and antigens derived from Cryptococcus neoformans. T h i s finding is a notable departure from the results in fatal cases of the other deep mycoses, where this reaction usually occurs in high titer. It has generally been concluded simply that Cryptococcus neoformans is not able to stimulate such antibody production in the host because of the comparative isolation provided by its capsule (Fisher). It seems at least equally plausible, however, that the fault may lie in the antigen. It will be recalled that in other deep mycoses effective complement-fixing antigens apparently must contain some nitrogen, probably in protein-like groupings or in the amino acid structure of the molecule, and that this component is easily destroyed in extraction and sterilization procedures. Because the majority of the mass of Cryptococcus neoformans obtained from cultures consists of capsular material which is almost entirely polysaccharide, it is probable that special techniques will have to be developed to remove the excess capsular polysaccharide in order to obtain extracts from the centrally located fungus cells themselves, before success can be achieved. Neill's (Neill, Abrahams, and Kapros, 1950) advocacy of the use of a strain of C. neoformans which produces much smaller capsules than usual is a step in this direction. T h e extraction should be very gently accomplished to prevent loss or denaturation of any potent material that may be present. Salvin and R . F. Smith (1961) reported a method of obtaining an antigen for skin testing which eliminates the larger part of the capsular material. T h e y

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forced the culture material through a tiny aperture at a pressure of 60,000 pounds per square inch which considerably disrupted the capsules. After washing this part away, the material was once again forced through the aperture, and the cells themselves were thus disrupted. A n extract made from this material contained about two-thirds as much protein-like substance as polysaccharide. Skin testing in animals yielded delayed reactions of the type considered significant in other deep mycoses. A n antigen like this one should certainly be tested for complement-fixing ability in severe human cryptococcosis. Bloomfield, Gordon, and Elmendorf (1963) have recently reported a method of detecting an antigen rather highly specific for C. neoformans in serum and cerebrospinal fluid, using a rapid, sensitive slide test in which latex particles coated with a specific antibody are agglutinated. This test was positive in seven of nine patients with central nervous system (CNS) cryptococcosis, and in one case served to make the diagnosis before cultures revealed the causative organisms. There were some false positives owing to cross reactions with rheumatoid factor, but in comparatively low titer. THERAPY

When cryptococcosis is sufficiently well developed to be diagnosed it is dangerous enough to life to warrant all available therapeutic measures, including reasonably effective antifungal drugs, even if they are of undesirable toxicity. All the general supportive measures previously outlined should be rigidly enforced, except that, according to Littman (1959), thiamin should be omitted from the vitamin B complex. This vitamin should also be omitted from the diet, insofar as possible, because it is necessary to the growth of the fungus, and, when present in the diet or by supplementation, it appears in the spinal fluid in large concentrations and thus attracts the organism. Louria (1960), pointing out that animal studies do not confirm this view, fears that induced deficiency in thiamin may harm the patient more than it does the fungus. Littman (1959) also suggested that the administration of gamma globulin may be indicated, especially if its level in the blood is low. With a very few possible exceptions, it is doubtful that any person ever became entirely cured of CNS cryptococcosis before the advent of amphotericin B. Even when untreated, however, a small percentage sustained remissions, only to relapse later, making all successes produced by drug administration look similar. Amphotericin B has notably improved this outlook. T h e fungus is usually sensitive to very small concentrations of the drug, sometimes even as low as 0.02 microgram percent, although animal studies have indicated that this fungus is somewhat more difficult

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to eradicate from tissues than those that cause histoplasmosis and North American blastomycosis. Louria reviewed sixty-nine cases of cryptococcosis meningitis treated intravenously with amphotericin B, in amounts of 500 mg or more. Fifteen of these were classed as cured by the criteria of complete clinical recovery, sterile cultures, return to normal of the cell, protein, and glucose values of the spinal fluid, and maintenance of this status during a follow-up period of at least twelve months. An additional thirty-one cases exhibited improvement, but still showed some abnormal spinal-fluid characteristics or had not been observed for the arbitrarily selected twelve months at the time of writing. Twenty-three patients failed to improve, relapsed, or died. A minimum of two months of such therapy is recommended, and usually a much longer period. When the central nervous system was not involved, the results were even more encouraging. Of eleven patients, nine recovered or showed marked improvement. Although these results are far better than ever obtained with any other therapy, they leave much to be desired in more than 50 percent of the cases. It has been suggested that some strains of the fungus may be more resistant than others to amphotericin B, but it seems more likely that the reason that the percentage of cures is not higher is the failure of the spinal fluid to attain a very high level of the drug even while it is adequate in the circulating blood. Hence, intrathecal administration is being evaluated, thus far without any significant increase in the percentage of cures. Arachnoiditis is a troublesome complication; to minimize it Littman (1959) suggests a maximum of 0.7 mg per dose on alternate days. Perhaps the intracisternal route being evaluated by Winn in coccidioidomycosis would be better tolerated. T h e advisability of using corticosteroids to lessen the toxic effects of amphotericin B in patients with cryptococcosis cannot be established at this time. They should be employed minimally if at all. Surgical removal of parts of the lung harboring resistant cryptococcosis may be advisable. Amphotericin B should be used both before and after an operation. Bibliography Almeida, F. P. de. 1961. Some data on cryptococcosis in South America. [In Spanish.] Mycopathologia, 15:389. Appelbaum, E., and S. Shtokalko. 1957. Cryptococcus meningitis arrested with amphotericin B. Ann. Intern. Med., 47:346. Barrash, M. J., and M. Fort. i960. Amphotericin B therapy in torula meningitis. Arch. Intern. Med., 106:271. Baum, G. L., and D. Artis. 1963. Characterization of the growth inhibition factor for Cryptococcus neoformans in human serum. Amer. J. Med. Sci., 246:53.

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Benham, R. W. 1935. Cryptococci: their identification by morphology and by serology. J. Infect. Diseases, 57:255. Biddle, A., and H. Koenig. 1958. An agent effective against cryptococcosis of the central nervous system. Arch. Intern. Med., 102:801. Bloomfield, N., M. A. Gordon, and D. F. Elemendorf. 1963. Detection of Cryptococcus neoformans antigen in body fluids by latex particle agglutination. Proc. Soc. Exptl. Biol. Med., 114:64. Carnecchia, B. M., and J. F. Kurtzke. i960. Fatal toxic reaction to amphotericin B in cryptococcal meningoencephalitis. Ann. Intern. Med., 53:1027. Carter, H. S., and J. L. Young. 1950. Note on the isolation of Cryptococcus neoformans from a sample of milk. J. Pathol. Bacteriol., 62:271. Castellani, A. 1963. Balanoposthitis chronica ulcerativa cryptococcica. Dermatol. Trop., 2 (July-Sept.): 137Cawley, E. P., R. H. Grekin, and A. C. Curtis. 1950. Torulosis: a review of the cutaneous and adjoining mucous membrane manifestations. J. Invest. Dermatol., 14:327. Collins, V. P. 1950. Bone involvement in cryptococcosis (torulosis). Amer. J. Roentgenol., 63:102. Cox, L. B., and J. C. Tolhurst. 1946. Human torulosis. Melbourne: Melbourne University Press. Crounse, R. G., and A. B. Lerner. 1958. Cryptococcosis: case with unusual skin lesions and favorable response to amphotericin B therapy. Arch. Dermatol., 77:210. Dillon, M. L., and W. C. Sealy. 1962. Surgical aspects of opportunistic fungous infections. Lab. Invest., 11:1231. Dormer, B. A., and M. Findlay. i960. Generalized cryptococcosis with osseous involvement. S. African Med. J., 34:611. Durant, J. R., L. D. Epifano, and S. W. Exer. 1960. Pulmonary cryptococcosis: treatment with amphotericin B. Ann. Intern. Med., 53:534. Emanuel, B., E. Ching, A. Lieberman, and M. Golden. 1961. Cryptococcus meningitis in a child treated successfully with amphotericin B, with a review of the pediatric literature. J. Pediatr., 59:577. Emmons, C. W. 1951. Isolation of Cryptococcus neoformans from soil. J. Bacteriol., 62:685. . 1953. Cryptococcus neoformans strains from a severe outbreak of bovine mastitis. Mycopathol. Mycol. Appl., 6:231. . 1962. Natural occurrence of opportunistic fungi. Lab. Invest., 11:1026. Evans, E. E. 1949. An immunologic comparison of twelve strains of Cryptococcus neoformans. Proc. Soc. Exptl. Biol. Med., 71:644. Evans, E. E., and J. F. Kessel. 1951. The antigenic composition of Cryptococcus neoformans. II. Sereologic studies with the capsular polysaccharide. J. Immunol., 67:109. Evans, E. E., and J. W. Mehl. 1951. A qualitative analysis of capsular polysaccharides from Cryptococcus neoformans by filter paper chromatography. Science, 114:10. Feldman, R. 1959. Cryptococcosis (torulosis) of the central nervous system, treated with amphotericin B during pregnancy. Southern Med. J., 52:1415. Fitchett, M. S., and F. D. Weidman. 1934. Generalized torulosis associated with Hodgkin's disease. Arch. Pathol., 18:225.

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Fitzpatrick, M. J., and C. M. Poser, i960. The management of cryptococcal meningitis. Arch. Intern. Med., 106:261. Fitzpatrick, M. J., H. Rubin, and C. M. Poser. 1958. The treatment of cryptococcal meningitis with amphotericin B, a new fungicidal agent. Ann. Intern. Med., 49=249Foley, G. E., and L. L. Uzman. 1952. Studies on the biology of Cryptococcus. IV. Isolation of a highly polymerized polysaccharide from encapsulated strains. J . Infect. Diseases, 90:38 Frisk, A., and B. Holmgren. 1959. Amphotericin B vid cryptococcus meningit. Nordisk Medicin, 61:927. Furtado, T . A. 1962. Cryptococcosis: first six cases observed in Minas Gerias (Brazil), and treatment of two cases with amphotericin B. [In Portuguese.] Hospital (Rio), 62:151. Gadebush, H. H., and P. W. Gikas. 1963. Natural host resistance to infection with Cryptococcus neoformans: the influence of thiamine on experimental infection in mice. J . Infect. Diseases, 112:125. Gandy, W. M. 1950. Primary cutaneous cryptococcosis. Arch. Dermatol. Syphil., 62:97. Ganta, J . A., J . A. Neutzel, and J . B. Keller. 1958. Cryptococcal meningitis treated with amphotericin B. Arch. Intern. Med., 102:795. Gendel, B. R., M. Ende, and S. F. Norman. 1950. Cryptococcosis: a review with special reference to apparent association with Hodgkin's disease. Amer. J . Med., 9=343Halde, C. 1964. Percutaneous Cryptococcus neoformans inoculation without infection. Arch. Dermatol., 89:545. Harland, W. A. i960. Cryptococcosis: a report of 5 cases. Canad. Med. Assoc. J., 83:580. Holtz, K. H. i960. Torulosis (cryptococcosis) with skin involvement: report of case treated with amphotericin B. Arch. Klin. Exptl. Dermatol., 211:347. Kent, T . H., and J . M. Layton. 1962. Massive pulmonary cryptococcosis. Amer. J . Clin. Pathol., 38:596. Kligman, A. M. 1947. Studies of the capsular substance of Torula histolytica and the immunologic properties of torula cells. Amer. J . Trop. Med., 27:395. Kligman, A. M., A. P. Crane, and R. F. Norris. 1951. Effect of temperature on survival of chick embryos infected intravenously with Cryptococcus neojormans. Amer. J . Med. Sci., 221:273. Kress, M. B., and J . R . Cantrell. 1963. Pulmonary and meningeal cryptococcosis: successful treatment of the meningitis with lateral cerebral intraventricular injection of amphotericin B. Arch. Intern. Med., 112:386. Lester, J . P., J . C. Lane, W. H. Kern, and J . C. Jones. 1962. The surgical treatment of isolated pulmonary cryptococcosis. J . Thorac. Cardiovasc. Surg., 44:207. Littman, M. L. 1958. Capsule synthesis by Cryptococcus neoformans. Trans. N.Y. Acad. Sci., 2d ser., 20:623. . 1959. Cryptococcosis (torulosis) current concepts and therapy. Amer. J . Med., 27:975. Littman, M. L., and L. E. Zimmerman. 1956. Cryptococcosis: torulosis or European blastomycosis. New York: Grune and Stratton.

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Louria, D. B. i960. Specific and non-specific immunity in experimental cryptococcosis in mice. J. Exptl. Med., 111 ¡643. Louria, D. B., T . Kaminsky, and G. Finkel. 1963. Further studies on immunity in experimental cryptococcosis. J. Exptl. Med., 117:509. McGibbon, C., and M. Readett. i960. Torulosis presenting in a skin department. Brit. J. Dermatol., 72:430. Marshall, J. D., L. Iverson, W. C. Eveland, and A. Kase. 1961. Application and limitations of the fluorescent antibody stain in the diagnosis of cryptococcosis. Lab. Invest., 10:719. Martin, W. J., D. R. Nichols, H. J. Svien, and J. A. Ulrich. 1959. Cryptococcosis: further observations and experiences with amphotericin B. Arch. Intern. Med., 104:4. Mello, R. P., and G. de A. Teixera. 1962. Cryptococcosis in the initial phase of dissemination. [In Portuguese.] Hospital (Rio), 61:355. Mook, W. H., and M. Moore. 1936. Cutaneous torulosis. Arch. Dermatol. Syphil., 33:95iNeill, J. M., I. Abrahams, and C. E. Kapros. 1950. A comparison of the immunogenicity of weakly and strongly encapsulated strains of Cryptococcus neoformans. J. Bacterid., 59:263. Neill, J. M., and C. E. Kapros. 1950. Serologic tests on soluble antigens from mice infected with Cryptococcus neoformans and Sporotrichum schenckii. Proc. Soc. Exptl. Biol. Med., 73:557. Pariser, S., M. L. Littman, and J. L. Duffy. 1961. Cryptococcal meningo-encephalitis associated with systemic lupus erythematosus. J. Mount Sinai Hosp. (N.Y.), 28:550. Rook, A., and B. Woods. 1962. Cutaneous cryptococcosis. Brit. J. Dermatol., 74:43. Rubin, H., and M. L. Furcolow. 1958. Promising results in cryptococcal meningitis. Neurology, 8:590. Salvin, S. B., and R. F. Smith. 1961. An antigen for the detection of hypersensitivity to Cryptococcus neoformans. Proc. Soc. Exptl. Biol. Med., 108:498. San Felice, F. 1894. Contributo alia morfologia e biologia dei blastomiceti, chi sviluppano nei succhi di alcuni frutti. Ann. Istol. Igiene R. Univ. Roma, 4:463. Silva, M. E., and L. A. Paula. 1963. Isolation of Cryptococcus neoformans from excrement and nests of pigeons in Salvador, Bahia (Brazil). [In Portuguese.] Rev. Inst. Med. Trop. (Sao Paulo), 5:9. Smith, C. W., J. A. Kemp, W . E. Farrar, Jr., J. W. Kemble, and D. F. Philpot, Jr. i960. Cryptococcosis of the central nervous system: 4 cases treated with amphotericin B. Southern Med. J., 53:305. Smith, G. W. 1958. T h e treatment of torula meningoencephalitis with amphotericin B. J. Neurol. Surg., 15:572. Spickard, A., W. T . Butler, V. Andriole, and J. P. Utz. 1963. T h e improved prognosis of cryptococcal meningitis with amphotericin B therapy. Ann. Intern. Med., 58:66. Stein, J. M., and P. J. Burdon. i960. Cryptococcus neoformans infection of the central nervous system: a case treated by amphotericin B with postmortem examination. Ann. Intern. Med., 52:445. Stoddard, J. L., and E. C. Cutler. 1916. Torula infection in man. Studies Rockefeller Inst. Med. Research, 25:1.

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Utz, J . P. 1962. The spectrum of opportunistic fungus infections. Lab. Invest., 11:1018. Verse, M. 1914. Über einen Fall von generalisierter Blastomykose beim Menschen. Verhandl. Deutsch. Pathol. Ges., 17:275-278. [From Cox and Tolhurst via Freeman.] Vogel, R. A., T . F. Sellers, Jr., and P. Woodward. 1961. Fluorescent antibody techniques applied to the study of human cryptococcosis. J . Amer. Med. Assoc., 178:921. Welsh, J . D., D. W. Foerster, W. A. Camp, and E. R. Rhoads. 1959. Torula meningitis treated with amphotericin B. J . Okla. Med. Assoc., 52:681. Wilson, J . W. 1957. Cryptococcosis (symposium on systematic mycoses). J . Chron. Diseases, 5:445-459.

10 Actinomycosis

INTRODUCTION AMONG THE members of a large group of primitive fungi named Actinomycetales, closely allied to bacteria, a few species are capable of causing disease in man and animals. T h e Actinomycetales are often classed by bacteriologists as higher bacteria, whereas mycolog'sts refer to them as fungi, pointing out that, in fact, all bacteria are really fungi, belonging as they do to the class Schizomycetes. T h e best-known members are the mycobacteria, which include the widespread organisms causing tuberculosis and leprosy. Most of the remaining pathogenic species cause a clinical syndrome characterized by a chronic granulomatous suppurative process, which slowly extends in many areas, while tending to heal with intense induration in others; it is seldom disseminated by the blood or the lymphatic channels. Although there are many similarities in the clinical pictures, and most of the differences can actually be attributed to the influence of the part of the body affected, it is customary to divide most of the group into two sections, actinomycosis and mycetoma (or sometimes

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maduromycosis). One species, Nocardia asteroides, produces an entirely different disease, nocardiosis, to be discussed separately (see chap. 11). Actinomycosis is therefore here used to designate only the disease produced by two anaerobic organisms called Actinomyces israelii and A. bovis, formerly considered as variants of one species. HISTORY As early as 1857 Lebert reported a disease in man which was almost certainly actinomycosis. Bollinger (1877) is usually credited with its first delineation when he described lumpy jaw in cattle; in 1877 Ponfick pointed out its similarity to the disease that Israel had recently observed in man. Harz (1879) named the organism Actinomyces (the ray fungus) because of the appearance of the tiny masses of the fungi seen in pus and in tissues. Wolff and Israel (1891) succeeded in culturing the organism, and carefully studied it. T w o decades later Lord (1910) reported its presence in normal mouths and tonsils. Emmons (1936) observed it in carious teeth and tonsillar crypts in a high percentage of persons not exhibiting the disease as we know it, thereby establishing the fact that the infection is almost exclusively endogenously acquired. Rosebury, Epps, and Clark (1944) confirmed this finding by demonstrating the organism in scrapings from various areas of the mouth and in the sputum of normal individuals. ETIOLOGY Although it was long believed that lumpy jaw in cattle and actinomycosis in man were caused by the same organism, Actinomyces bovis, with strains perhaps sufficiently different to be classed as two varieties, more recently it has been pointed out that one type limits its activities almost exclusively to animals while the other does so as consistently to man. Because the organism affecting cattle was named first, it retains the name A. bovis, and the human type is called A. israelii. Since etiology is defined as "the study of the cause of disease," it is appropriate to point out that bacteria are invariably associated with Actinomyces in the disease actinomycosis, and that they undoubtedly play an active part in its causation. These bacteria are not only of one type, but comprise various gram-negative bacilli, including Bacillus coli, fusiform bacilli, and even one named Bacterium actinomycetemcomitans because of its frequent connection with actinomycosis. DISTRIBUTION There is no geographic limitation to, or concentration of cases of, actinomycosis. As Cope (1938) observes, it exists "wherever there is a microscope

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and a laboratory" with personnel capable of making the diagnosis. No age group is exempt, but those most frequently affected are between twenty and forty. Males predominate two to one in the United States, but less so elsewhere. EPIDEMIOLOGY When a disease is present in all parts of the world it is obvious that man either carries the causative organism with him wherever he goes, or encounters it frequently because it is universally distributed in nature. The former is true with regard to actinomycosis; except for an occasional report of infection transferred from mother to child, and one case originating from a human bite, the disease has apparently always been endogenously acquired. The earlier belief that man commonly became infected by picking his teeth with stems of plants or chewing on bits of grass, presumably where diseased cattle had grazed and left the fungi, has been entirely refuted by the demonstration that the causative organisms are consistently of different species. Actinomyces israelii has, in fact, never been recovered from nature. When an organism like A. israelii, which ordinarily exists as a harmless saprophyte in or on an animal, succeeds in causing disease, the infection is said to be endogenously acquired; other more familiar examples are those due to certain streptococci and staphylococci. It is extremely important to consider the contributory factors that endow normally innocuous organisms with pathogenic powers, for measures directed against such factors may be more effective in prevention, as well as in therapy, than those directed against the microbes themselves. In actinomycosis caused by A. israelii the most important such factor is trauma, especially when the injured, devitalized tissue is far enough from the surface of the body to furnish the anaerobicity that the fungus desires. For example, actinomycosis frequently follows the extraction of infected teeth or fractures of the jaw, and occasionally results from bites inflicted by animals or human beings. The presence of disease owing to other causes may also induce actinomycosis by lowering resistance. Another important contributory factor, especially where therapy is concerned, is that A. israelii seems to establish a symbiotic alliance with certain endogenous bacteria, the combination exhibiting a degree of pathogenicity not possessed by either ally alone. As a consequence, some of the effectiveness of sulfonamide and antibiotic therapy in actinomycosis is probably due to antagonism against these bacterial allies rather than against the fungus itself. Significantly, it has usually been impossible to infect animals experimentally with A. israelii in the absence of trauma or concomitant bacterial infection. These facts seem adequate to explain the universal distribution of actinomycosis; wherever man exists, he carries with him these organisms awaiting only the proper opportunity to cause disease.

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Actinomycosis CLINICAL

CHARACTERISTICS

T h e r e are several well-defined clinical forms of actinomycosis. In considerably more than half of the cases it occurs in the region of the face or neck, and is called the cervicofacial type. T h e abdomen is the site in about 20 percent of the cases, and the chest, in 15 percent. In the few remaining cases the area is extremely variable; in the approximate order of frequency, involvement occurs in extremities, skin, bones, joints, kidneys, ovaries, liver, or central nervous system. Often, however, such lesions arise by extension from one of the three more common types. Cervicofacial actinomycosis T h e portal of entry for Actinomyces israelii is most often the region about the teeth, gums, jawbone, or tonsils. T h e infection frequently follows the extraction of infected teeth or fractures through the tooth-bearing areas of persons maintaining poor oral hygiene. T h e mandible is commonly involved, usually near the angle of the jaw. T h e region of the

Fig. 9. Actinomycosis: destruction of acromion ticular cartilage of acromioclavicular joint.

process and ar-

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Fig. 10. Actinomycosis: destruction of ramus and body of left mandible. Marked periosteal formation.

maxillary sinus is also particularly susceptible. Primary infections have been described in the lacrimal glands, the orbit, the tongue, or the lower pharynx or larynx, but many of them were probably derived by extension from the maxillary region. At first the infection does not differ from the more common bacterial infections of low grade, but soon the overlying skin becomes darkly purple or red, and beneath it there develops a degree of induration of such firmness as to have been called "woody" (ligneous phlegmon). There is often muscular spasm, and motion may be limited. Slowly the surface

2 1 . Cryptococcosis: cutaneous lesions. Upper left: multiple cutaneous necrotizing lesions early in course of severe disseminated cryptococcosis. Lower left: cutaneous lesions in far-advanced disseminated cryptococcosis, showing gelatinous exudate consisting largely of encapsulated fungal organisms. Right (from top to bottom): successive stages in development of necrotizing cutaneous lesions in disseminated cryptococcosis in same patient. Upper right: appearance of first stage, a semitranslucent elevation simulating a vesicle, or at times a basal cell carcinoma ( x 2). PLATE

P L A T E 22. Cryptococcosis: cutaneous lesions. Upper four pictures: cicatrization of lesions as healing occurred during successful therapy. Lower left: cutaneous lesion on shoulder of type spreading peripherally, closely resembling ulcerative basal cell carcinoma with semitranslucent "rolled" border. Lower right: same type on nape.

PLATE 23. Cryptococcosis: histopathology. Upper and middle left: tissue sections of lung in cryptococcosis, showing masses of fungal cells practically replacing normal stroma, and with no leucocytes from host to indicate cellular resistance, the socalled gelatinous tumors (H & E x 200). Lower left: same (PAS X250). Upper and middle right: same (PAS X400). Lower right: gross appearance of Cryptococcus neoformans colony in culture on Sabouraud's medium.

24. Cryptococcosis: histopathology and cultural characteristics. Upper left: cutaneous lesion in partly resisted disease, showing peripheral erythema. Middle and lower left: erythema almost entirely absent owing to lack of immunologic resistance. Upper right: encapsulated organisms of Cryptococcosis neoformans as seen in microscopic examination of centrifuged spinal fluid mixed with India ink ( x 400). Lower right: histopathological preparation of severely involved tissue; absence of leucocytes shows host's lack of cellular resistance (PAS with yellow counterstain x 400). PLATE

P L A T E 2 5. Actinomycosis: cervicofacial type. Caused by Actinomyces israelii. Upper left: early lesion resulting from peridental abscess burrowing to surface to simulate an infected sebaceous cyst. Middle left and upper right: same, but after rupture, leaving a draining sinus with pyogenic granuloma at openings. Lower left: tremendous swelling, hard and woody to palpation with multiple draining sinuses laterally in facial actinomycosis. Lower right: actinomycosis of tonsillar area.

P L A T E 26. Actinomycosis and nocardiosis: neck, hand, and back lesions. Upper left: actinomycosis caused by Actinomyces israelii, cervical type, not yet ruptured. Middle left: same after many months of chronic involvement, showing multiple draining sinuses and new lesions in midst of fibrosis. Lower left: chronic involvement of wrist in actinomycosis. Upper and lower right: extensive involvement of chest wall by direct extension from pulmonary disease caused by Nocardia brasiliensis.

PLATE 27. Actinomycosis and nocardiosis: histopathology and cultural characteristics. Upper left: Nocardia asteroides in tissue (Gram stain X700). Middle left: same (Ziehl-Neelsen stain, showing acid-fastness X700). Lower left: Actinomyces israelii, showing anaerobic growth remaining well below surface of thioglycolate broth. Right panel: gross appearance of colonies of aerobic species of Nocardia on Sabouraud's agar. Upper right: N. asteroides. Middle right: N. brasiliensis. Lower right: iV. madurae (somewhat enlarged).

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becomes irregularly swollen; abscesses develop periodically and finally rupture or are incised, leaving sinus tracts which persist for months, discharging serosanguinous or purulent fluid containing tiny, yellowishwhite, friable masses of the causative fungi, the so-called sulfur granules. Healing of some areas occurs by firm cicatrization, while others nearby are developing into new lesions. All stages of the above processes are usually present simultaneously in contiguous areas. The disease exhibits little tendency to clear completely, often continuing chronically for years. The symptoms are usually less serious than the extent of the disease would indicate, and so long as the infection remains well localized the general health of the patient is not greatly affected. The bone is often shown to be involved by X-ray studies. The disease usually begins as periostitis, indicating that the infection has approched the bone from the adjacent tissues instead of being blood-borne. Osteomyelitis develops, followed by destruction and rarefaction of some areas combined with bony proliferation, producing fuzzy, irregular borders. Occasionally, however, smoothly outlined cysts develop, indicating hematogenous dissemination. Abdominal actinomycosis As the causative fungi are frequently present in the intestine in normal persons, injuries puncturing its wall, such as knife or gunshot wounds, may initiate abdominal actinomycosis. Frequently an apparently nontraumatic form originates in the appendiceal area. Sometimes the ovarian tubes, the gallbladder, or the liver seems to be the primary focus. Occasionally a mass can be palpated. Differentiation from other types of appendicitis, salpingitis, cholecystitis, cystitis, or pyelonephritis is very difficult. Usually the correct diagnosis is made only after exploratory laparotomy, unless some of the abscesses have approached the surface of the body and ruptured to produce the typical draining sinuses from which the organisms can be recovered. X-ray studies may reveal suggestive areas of involvement of the proper type in the bones of the pelvis or in the vertebrae. According to Simpson and Mcintosh, actinomycosis, in contrast with tuberculosis, favors articular facets, laminae, and transverse and spinous processes rather than vertebral bodies. Thoracic actinomycosis Primary pulmonary actinomycosis is caused by the aspiration of material from the mouth. It is impossible in the early stages to differentiate it from other low-grade chronic pulmonary diseases. The early appearance of expectorated bloody pus, indicating the presence of small abscesses, is helpful. Sometimes the process penetrates the chest wall to form, at the surface of the body, the typical discharging sinuses of actinomycosis, even without signs that the pleura has been involved. The symptoms include

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dyspnea, fever, night sweats, anemia, and progressive wasting. Physical signs are sometimes of value in differentiating actinomycosis from tuberculosis by revealing that the bases rather than the apices are involved. X rays usually also reveal basilar involvement, more commonly bilateral, consisting of consolidations extending outward from the hilus, simulating neoplasm. Sometimes the differentiation can be made by observing small areas of rarefaction within such masses, caused by actinomycotic abscesses. Pleural effusion is frequently seen, and adhesions are common. Invasion of the ribs often occurs, and conforms to the type of bone involvement previously described. Other forms of actinomycosis A n y part of the body may be affected by actinomycosis, either by direct extension or, rarely, by hematogenous dissemination. A wide variety of symptoms and signs are thus produced. Carrion and Cope (1938) have covered this subject more thoroughly than is appropriate here. Infection occurs by direct inoculation through or into the skin, most commonly on the foot or the leg. Ulceration develops, which gradually penetrates deeper and eventually assumes the classical picture of actinomycosis. Most authors have treated this skin disease separately from actinomycosis, calling it " M a d u r a foot," "maduromycosis," or "mycetoma," even w h e n caused by A. israelii. T h e basic clinical picture is the same, however, the principal difference being the location of the disease in the body. In twenty-five cases reported by Merian the skin appeared to have been the portal of entry; the infection began superficially but, gradually penetrating more deeply, eventually assumed the typical picture. Jacobson reported thirteen cases as primary in the kidney, but did not explain how the organisms arrived there. PATHOLOGY Grossly, the pathology of actinomycosis is characterized by a dense cellular infiltration producing in general a surprising firmness; a softening in many areas is caused by abscess production, leading to sinus formation which is followed in most instances by cicatricial healing. A l l these processes go on simultaneously in contiguous areas. T h e infection spreads by burrowing along fascial planes, leaving much intercommunication among the residual sinus tracts. Cavities filled with purulent and necrotic debris are common. In the typical microscopic picture, actinomycotic granules up to 25 microns in diameter may be seen in the centrally cut sections of an abscess. T h e central part is surrounded by polymorphonuclears. N e x t is a zone of granulation tissue containing histiocytes, foamy because of being filled with lipids. Leucocytes, plasma cells, and connective tissue cells form the

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abscess wall. W h e n stained with hemotoxylin and eosin, the granule of A. israelii exhibits a central basophilic area, irregularly circular in outline, which is composed of tiny, closely packed, branching filaments about 1 micron in diameter. T h i s dark area gradually shades into an acidophilic peripheral in which filaments are distributed as though they were radiating from a central focus. Many of these filaments seem to be enlarged at their tips by being surrounded by a gelatinous sheath, forming "clubs"; the material in these clubs is now thought to be contributed by the host as part of the defense process. T h e P A S and Gridley stains are not useful in actinomycosis, b u t Gram's method is often helpful. DIFFERENTIAL

DIAGNOSIS

Actinomycosis usually presents a strongly suggestive clinical picture rather easily confirmed by biopsy and histopathologic study. T h e culture of A. israelii is difficult (see below), and at times seems to require luck as well as technical ability. T h e cervicofacial form of actinomycosis may be confused with bacterial infections arising from abscessed teeth, which often present burrowing sinuses discharging onto the surface of the skin. A b d o m i n a l actinomycosis is difficult to distinguish from chronic appendicitis, amebiasis, salpingitis, pyelonephritis, or liver abscess. Pulmonary actinomycosis may mimic neoplasm, sarcoidosis, or bacterial lung abscess. T h e granules characteristic of actinomycosis are perhaps the easiest clue obtainable when they are seen in pus or exudate from lesions. Nevertheless, the discovery of granules does not necessarily identify the disease as actinomycosis, for granules of grossly similar appearance are occasionally produced by bacteria of several types (actinobacilli), or may be nothing more than coagulated fibrinous material. MYCOLOGY It is customary to call the organism that causes human actinomycosis Actinomyces israelii, and the one that causes cattle infections A. bovis, but there are apparently some instances of variation from this rule. T h e two are so similar that for years they were accepted simply as variants of a single species. Most strains of A. israelii produce colonies with rough surfaces, appearing dull white, heaped-up, and irregular, and showing spider-like filaments on the surface of the agar when the gross colony is examined under the microscope. W h e n tiny, these colonies have been likened to the occlusal surface of a molar tooth. In liquid thioglycolate medium the organism produces discrete lobulated colonies which resemble bread crumbs, and granules limited to the region x centimeter below the surface of the broth because of the organism's anaerobic proclivity. Direct examination

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of these clumps reveals branched filaments, better seen after gram-staining. T h e filaments break u p very easily into bacillary, coccoid, or diptheroid forms. A. bovis usually produces smooth-surfaced, moist, glistening colonies, compact and rounded, without filaments extending from the periphery. I n liquid thioglycolate m e d i u m the organism produces turbidity more often than clump formation, and much of the sediment sinks to the bottom of the tube. A soft, diffuse growth with streamers downward, which forms spirals when the tube is rotated, has been described. Microscopically, branching forms are difficult to demonstrate because the filaments break very easily into diptheroid segments. Both species need expert attention for isolation and identification. T h e inoculum is always heavily contaminated with bacteria, many of them equally anaerobic in growth requirements. Enriched media such as brainheart infusion with added blood and starch are necessary, as well as maintenance of a p H between 6.8 and 7.5 and incubation at 37°C. A n atmosphere of 5 percent C 0 2 is also helpful in 95 percent nitrogen. These fungi are difficult to maintain in artificial culture, and die easily on attempted transfer. It is often impossible to obtain p u r e colonies, separated from the concomitant bacteria. An organism n a m e d Actinomyces naeslundi is often found in normal h u m a n mouths. As it usually grows aerobically as well as anaerobically, it may be eliminated from consideration. Granules obtained f r o m pus, exudate, or s p u t u m may be crushed between slide and cover slip and examined microscopically. T h e y are more easily f o u n d on the surface of gauze covering wounds, into which the fluid portion of the exudate has soaked. It is also helpful to allow the liquid material to flow along the side of the tube, where granules are easily seen through the glass. But the mere establishment of the presence of granules is not enough. T h e y should be smeared onto a slide, gramstained, and microscopically examined. T h e y will reveal thin mycelial threads n o t more than 1 micron in diameter, which exhibit branching. T h e r e are many bacilliform elements representing fragmented hyphae, as well as the inevitably concomitant bacteria themselves. Animal inoculation serves n o purpose in the diagnosis of actinomycosis. Most attempts to produce infection have failed, even with the concentrations of the fungi afforded by cultures, unless accompanied by deep inoculation in injured tissues with material containing the bacterial concomitants. For experimental work the hamster has been recommended. IMMUNOLOGY Although several reports have dealt with allergic and immunologic phenomena in actinomycosis, there is little consistency in the reactions, and it has not yet been possible to correlate most of them with the clinical

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course of the disease, or to use them for prognosis. Some of the inconsistencies in skin- and serum-testing procedures are undoubtedly due to variations in the chem'cal nature of the antigens employed, which are caused by differences in the methods of preparation. Actinomyces israelii is so difficult to culture on artificial media that it tends to die out after a transfer or two, which indicates that it is perhaps not sufficiently well pleased by the artificial environment to produce antigenic substances that are the same as or comparable with those connected with its pathogenic activities in the infected body. T h e intracutaneous injection of culture filtrates from A. israelii has yielded both local and systemic reactions, demonstrating hypersensitivity in persons possessing actinomycosis. T h e results have been interpreted in various ways. Mathieson et al. (1935) have concluded that some persons become sensitized in this manner from the Actinomyces living saprophytically in the intestinal tract, and that this hypersensitivity causes them to lose the power to resist the fungus and therefore to become infected. Because of this belief they recommend desensiiization as a therapeutic aid. In sharp contrast with this view, the development of hypersensitivity in several other deep mycoses is the rule rather than the exception, and the greater the degree of allergic reactivity (of the delayed tuberculin type) exhibited by the patient's skin, the better is the resistance to the progress of the disease by specific immunologic resistance. In this light, desensitization would appear to be illogical and perhaps even dangerous. Several studies have revealed that complement-fixing antibodies, as well as agglutinins and precipitins, are to be found in the serums of persons infected with actinomycosis, but, as Negroni (1936) has pointed out, there is a notable lack of evidence that they help to protect the individual against the disease. T h e experience with coccidioidomycosis, histoplasmosis, both North and South American blastomycosis, and probably sporotrichosis suggests that this conclusion is entirely consistent, for none of the antibodies thus far discovered in the serums of patients with these diseases offers any power to protect; in fact, the height of the titer in which they are found tends to parallel the severity of the disease. Perhaps these reactions in actinomycosis can be utilized by the clinician for prognostic purposes as they are now used in other infections, especially in conjunction with skin-test reactivity. Perhaps, before conclusions are reached, the same reaction tests should also be administered with extracts from cultures of the bacteria found in collaboration with Actinomyces in actinomycosis. THERAPY Because actinomycosis is not caused by the pathogenic activities of the fungus A. israelii alone, but only in alliance with one or more species of bacteria, it is just as important to determine the antibiotic sensitivity

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reactions of the bacteria, and to add appropriate antibiotics to the regimen, as it is to use the substance most likely to inhibit the fungus itself. Actinomyces israelii is as closely allied to bacteria as it is to fungi, and is in fact often classed with the former. Hence it is more likely to be effectively combated by antibacterial than by antifungal substances. Penicillin is still the drug of choice, most strains of the fungus being inhibited in vitro by concentrations of o.i unit per milliliter. There is, however, considerable variation, some of which is apparently explained by pointing out that in vitro large inocula are found to be more resistant than small ones, and that the drug may have difficulty in penetrating to the center of the relatively large granules produced by the organisms in the tissues. For this reason adequate concomitant surgical drainage is recommended, and even the removal of fibrotic masses of tissue still actively interspersed with the disease, into which the drug is carried only with difficulty through the impaired circulatory channels. For the same reason the dosage of penicillin should never be small, and should be long continued. Varying from 1 to 6 million units daily at first, it should then be gradually lessened, but should be continued for at least six weeks and sometimes for as long as three years. Some patients have received more than half a billion units. At times heavily filtered X-radiation may be of value, especially in cervicofacial actinomycosis. Actinomycosis seems to have been decreasing in incidence in late years, perhaps because the widespread routine use of penicillin and other antibiotics has prevented infection in injuries, tooth extractions, and compound fractures.

Bibliography Bollinger, O. 1877. Über eine neue Pilzkrankeit beim Rinde. Centralbl. Med. Wiss., 15:481. Cope, V. Z. 1938. Actinomycosis. London: Oxford University Press. . 1951. Actinomycosis of bone with special reference to infection of the vertebral column. J. Bone Joint Surg., 338:205. Del Rey Calero, J. i960. Hemagglutination tests in human serum of actinomycosis. [In Spanish.] Medicina (Madrid), 28(April):i88. Dundon, S., and C. K. Byrnes. 1963. Pulmonary actinomycosis in childhood. J. Irish Med. Assoc., 52(Jan.):26-28. Emmons, C. W . 1935. Actinomyces

and actinomycosis. Puerto Rico J. Public

Health Trop. Med., 11:63. . 1936. Strains of Actinomyces

bovis

isolated from tonsils. Puerto Rico J.

Public Health Trop. Med., 11:720. . 1938. T h e isolation of Actinomyces

bovis

from tonsillar granules. Public

Health Repts., 53:1967. Harvey, J. C.', J. R. Cantrell, and A . M. Fisher. 1957. Actinomycosis: its recognition and treatment. Ann. Intern. Med., 46:868.

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Harz, C. O. 1879. Actinomyces bovis: ein neuer Schimmel in den Geweben des Rindes. Jahrb. Centralbl. Tierarznei-schule München, p. 125. Jepson, E. M., F. C. Rose, and R. D. Tonkin. 1958. Thoracic actinomycosis. Brit. Med. J., 1:1025. Lamb, J. H., E. S. Lain, and P. E. Jones. 1947. Actinomycosis of the face and neck. J. Amer. Med. Assoc., 134:351. Lord, F. T . 1910. Presence of Actinomyces in contents of carious teeth and tonsillar crypts of patients without actinomycosis. J. Amer. Med. Assoc., 55:1261. McVay, L. V., Jr., D. Dunavant, F. Guthrie, and D. H. Sprunt. 1950. Treatment of actinomycosis with aureomycin. J. Amer. Med. Assoc., 143:1067. McVay, L. V., JA., and D. H. Sprunt. 1953a. A long-term evaluation of aureomycin in the treatment of actinomycosis. Ann. Intern. Med., 38:955. . 19536. T h e treatment of actinomycosis with isoniazid. J. Amer. Med. Assoc., 153:95. Mathieson, D. R., R . Harrison, C. Hammond, and A . T . Henrici. 1935. Allergic reactions to actinomycetes. Amer. J. Hyg., 21:405. Monteleone, L. 1963. Actinomycosis. J. Oral Surg., 21:313. Murphy, J. B. 1885. Actinomycosis in the human subject. N.Y. Med. J., 41:17. Negroni, P. 1936. Datos estadísticos sobre 50 casos de actinomicosis y de su tratamiento vacunuoterápica. Rev. Argentin. Dermatosif., 20:458. Paul, F. M. 1963. T w o cases of thoracic actinomycosis in children. Arch. Disease Childhood, 37:276-279. Peabody, J. W., and J. H. Seabury. i960. Actinomycosis and nocardiosis: a review of basic differences in therapy. Amer. J. Med., 28:99-115. Pine, L., et al., 1963. Determination of the structure and composition of the "sulfur granules" of Actinomyces bovis. J. Gen. Microbiol., 32:209. Pritzker, H. G., and J. S. Mackay. 1963. Pulmonary actinomycosis simulating bronchogenic carcinoma. Canad. Med. Assoc. J., 8:785-791. Robinson, R . A . 1944. Actinomycosis of subcutaneous tissue of the forearm secondary to a human bite. J. Amer. Med. Assoc., 124:1049. Rosebury, T . 1944. T h e parasitic actinomycetes and other filamentous microorganisms of the mouth: a review of their characteristics and relationships, of the bacteriology of actinomycosis and of salivary calculus in man. Bacteriol. Rev., 8:189. Rosebury, T . , L. J. Epps, and A . R . Clark. 1944. A study of the isolation, cultivation and pathogenicity of Actinomyces israelii recovered from the human mouth and from actinomycosis in man. J. Infect. Diseases, 74:131. Salvin, S. B. 1963. Immunologic aspects of the mycoses. Progr. Allergy, 7:213. . Slack, J. M., E. H. Ludwig, H. H. Bird, and C. M. Canby. 1951. Studies with microaerophilic actinomycetes. I. T h e agglutination reaction. J. Bacteriol., 61:721. Spilsbury, B. W., and F. R. Johnstone. 1962. T h e clinical course of actinomycotic infections: 14 cases. Canad. J. Surg., 5(Jan.):33. Strauss, R . E., A. M. Kligman, and D. M. Pillsbury. 1951. T h e chemotherapy of actinomycosis and nocardiosis. Amer. Rev. Tuberc. Pulmón. Diseases, 63:441. Thompson, L. 1950. Isolation and comparison of Actinomyces from human and bovine infections. Proc. Mayo Clin., 25:81. Warthin, T . A., and B. Bushueff. 1958. Pulmonary actinomycosis. Arch. Intern. Med., 101:239.

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Wayl, P., J . Rakower, and A. Hochman. 1958. Pulmonary ray fungous disease: clinical aspects and pathogenesis. Diseases of the Chest, 34:506. Weed, L. A., and A. H. Baggenstoss. 1949. Actinomycosis: a pathologic and bactériologie study of 21 fatal cases. Amer. J . Clin. Pathol., 19:201. Wolff, M., and J . Israel. 1891. Über Reincultur des Actinomyces und seine über Tragbarkeit und Thiere. Virchows Arch. Pathol. Anat., 126:11. Young, W. B. i960. Actinomycosis with involvement of vertebral column: case report and review of literature. Clin. Radiol. (London), 11:175.

1 1

Nocardiosis

INTRODUCTION Actinomyces israelii, several species of finely filamentous fungi belonging to the Actinomycetales group cause human disease. Although all species were originally classed in the genus Nocardia, some of them have been transferred to Streptomyces, by González-Ochoa. Most of this group cause infection in foot, leg, hand, or arm, and, along with a number of species of higher fungi which form the same clinical picture, are discussed under the heading of mycetoma by most observers working in the areas of highest incidence. There is, however, one fungus, Nocardia asteroides, which behaves differently and therefore deserves special treatment. It is discussed here under the heading of nocardiosis, even though diseases caused by other species of Nocardia are included in the discussion of mycetoma (see chap. 12). N. asteroides causés a generalized infection in man which usually begins ASIDE F R O M

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in the lungs. It leads to varying degrees of disease, and is frequently disseminated hematogenously to many organs, prominently to the central nervous system. HISTORY Eppinger (1890) described the first case of nocardiosis, culturing from pulmonary and central nervous system lesions an aerobic fungus which he called Cladothrix, characterized by very fine filaments. It was soon related morphologically to a fungus isolated by Nocard in 1899 from cattle infected with farcy; in 1895 Blanchard designated the genus Nocardia. Approximately 100 cases have been reported, the largest group being that collected by Kirby and McNaught in 1946. Other valuable information has come from Henrici and Gardner (1921), Drake and Henrici (1943), Binford and Lane (1945), Buchanan, Lurie, and R o u x (1948), Ballinger and Goldring (1957), and Larsen, Diamond, and Collins (1959). ETIOLOGY As stated above, only the disease caused by the species Nocardia is covered here.

asteroides

DISTRIBUTION N. asteroides is widely distributed over the globe, instances of the infection having been reported from most areas where diagnostic personnel are active. It is, however, somewhat more frequently diagnosed in the United States than would appear explainable by this factor alone. There is no age limitation for nocardiosis, although it predominates in the twenty- to forty-year group. Males are affected more than females by a ratio of better than 2 to 1. N o hypersusceptibility seems to be caused by skin color or race. Surprisingly, persons whose occupations bring them into more intimate contact with the soil, the natural habitat of N. asteroides, do not reveal a higher incidence of infection than persons not so occupied. EPIDEMIOLOGY In contrast with Actinomyces israelii, Nocardia asteroides has never been found in man in the absence of the disease itself. Nocardiosis therefore cannot be endogenously acquired. T h e fungus in virulent form was first isolated from soil by Gordon and Hagen (1936), and their finding has since been amply confirmed in other geographic areas. It is obvious that the fungus enters the body in most instances by

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being inhaled along with terrestrial dust, as in coccidioidomycosis and histoplasmosis. It follows that the disease may similarly occur in so mild a self-healing form as to remain subclinical and unrecognized in a large number of persons, among whom only the small percentage of immunologic defectives become seriously involved. As there are no studies of intracutaneous testing of large normal population groups with specific antigens extracted from the fungus, the frequency of these mild infections has not been established, but the fungus has been recovered from the sputum of persons with minimal pulmonary involvement, making such a thesis appear likely. Although animals, particularly dogs and cattle, acquire nocardiosis frequently, there is no recorded instance of its transfer directly from animals to man, or from man to man. CLINICAL

CHARACTERISTICS

Nocardiosis is almost always primarily a pulmonary disease resulting from inhalation of fungus spores. Often (especially because of its early recognition and treatment) the disease remains confined to the lungs, but dissemination by way of the bloodstream occurs frequently and early as well. In some reported cases of nocardiosis the initially observed lesions appeared in the appendiceal region or elsewhere in the gastrointestinal tract, suggesting that the infection was acquired by ingestion of the fungi on contaminated food. T h e same result could have followed the swallowing of sputum from the primarily infected lungs which contained the fungi, or hematogenous dissemination from that source. Sometimes the disease is acquired by direct inoculation of the causative organisms through the skin, in which event the resulting disease follows the clinical course described for mycetoma (see chap. 12). T h i s interpretation may be erroneous, however, because occasionally the infection has resulted from simple bruising of tissue without a break in the skin, followed by the appearance of the disease more deeply than would be likely from cutaneous inoculation. It is probable that at least some of these cases were really caused by hematogenous dissemination from the lungs, as in coccidioidomycosis and histoplasmosis. In fact, in 1961 Baumgarten reported from Australia one instance in a Nocardia asteroides infection of the typical chancriform picture which follows intracutaneous inoculation in these two diseases and in North American blastomycosis. Clinicians should therefore be wary of accepting the intracutaneous route as explaining nocardiosis, and of treating the patient locally only, until search for the disease elsewhere has been diligently carried out. Pulmonary nocardiosis has rarely been studied in the early phases because it is usually well developed before medical care is sought. There may be single lesions, but more often the lesions are scattered infiltrations,

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or they are miliary in type, resembling those in tuberculosis, but not tending to concentrate in the apices. There may be massive consolidation of one or more lobes. Cavitation is not rare. T h e symptomatology of nocardiosis is not distinctive. Fever, anorexia, weight loss, noctidrosis, pleurisy, and cough with blood-streaked sputum are typical. Occasionally cavitation may result in massive hemoptysis. One feature helpful in differentiating nocardiosis from tuberculosis is its tendency to extend through the pleural walls to involve the ribs and cause abscesses in the chest wall. As in actinomycosis, although less frequently, these abscesses may rupture and leave fistulous draining channels. T h e absence of the granules typical of actinomycosis would suggest the diagnosis of nocardiosis. T h e central nervous system is an area of predilection for disseminated nocardiosis, being affected in about a third of the cases. Indeed, symptoms referable to brain involvement are often the original complaint. T h e most common brain disease consists of single or multiple abscesses, suggesting tumor or bacterial infections. T h e meninges are not involved often enough to furnish diagnostic evidence in the spinal fluid. Disseminated nocardiosis often affects the kidneys, and less often the spleen, liver, adrenals, myocardium, and pericardium. Skin lesions have been reported most frequently in the chest wall around draining sinuses. PATHOLOGY Because Nocardia asteroides is closely allied with bacteria in causing disease, it is not surprising that the gross pathologic changes it induces are indistinguishable from those caused by bacterial infections. N. asteroides stimulates much less localized resistance than Actinomyces israelii, and hence there is less fibrosis and scarring in association with its lesions. A n intense pyogenic reaction commonly occurs, resulting in suppurative abscesses, within which the fungi can be demonstrated as delicate branched filaments, 1 micron or less in diameter. Only rarely do these accumulate into grossly visible masses such as the granules of A. israelii, but they are widely distributed, both freely and in microscopic clumps. T h e Gram or the Gomori stain serves best to reveal the organisms; they do not take well the special stains, such as PAS or the usual H 8c E, which are useful for other fungi. T h e hyphal strands are seldom very long, and branching is sometimes difficult to demonstrate; in fact, their tendency to break up into short segments resembling bacilli makes it easy to diagnose mistakenly a bacterial infection. T h i s problem is particularly troublesome because N. asteroides is moderately acid-fast, and thus may easily be confused with Mycobacterium tuberculosis in inexperienced hands. It is, however, not so resistant to decolorization by acid as is M. tuberculosis, especially if alcohol is omitted from the routine.

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DIFFERENTIAL

DIAGNOSIS

Nocardiosis in the pulmonary phases must be differentiated from a host of other lung diseases, ranging from subacute to chronic. In the early phases the recovery and identification of the fungus in sputum is the only reliable method. Later, its tendency to penetrate the chest wall and to appear as draining sinuses on the surface is very helpful. C N S nocardiosis most often simulates brain abscess, but it is sometimes confused with neoplasm or syphilis. Here also laboratory techniques must be employed, often only after surgical intervention or autopsy has furnished the necessary material. MYCOLOGY Nocardia asteroides was given its species name by Eppinger (1890), w h o called it Cladothrix asteroides when reporting the first case. His use of this name raises some doubt that he actually isolated the fungus, for it seldom produces the granules exhibiting the ray or starlike appearance signified by "asteroid." In 1896 Blanchard transferred the fungus to Nocardia, but retained the species name. In pus or sputum N. asteroides can be demonstrated by Gram's stain as small gram-positive bacilliform fragments, sometimes exhibiting a longer-strand formation with branching. These fragments are moderately acid-fast, and in tissues the same characteristics are adhered to as described above (see section on pathology). Nocardia asteroides grows well on artificial media, although very slowly, at both room and incubator temperatures. As it often survives the same concentration and digestion techniques as used for tuberculosis, A j e l l o (1951) recommended inoculation of material both before and after such treatment to assist in eliminating many contaminating bacteria. Sabouraud's dextrose agar is a satisfactory medium, and antibacterial antibiotics cannot be added because N. asteroides is also inhibited by them. Some strains grow better in the incubator. N. asteroides is also recoverable on the usual medium employed for M. tuberculosis, particularly at 37°C, and must be differentiated from it and from chromogenic mycobacteria by searching for branched forms. I n culture N. asteroides begins as white or cream-colored, moist-surfaced colonies, later becoming chalky and usually rather highly pigmented yellow to orange. Microscopically, it produces tiny filaments 1 micron or less in diameter, with branching as a characteristic. T h e chalky surface of some colonies shows very well the production of arthrospores, by which propagation also is carried out. Further identification is obtained by using Gram's stain and acid-fast techniques. Nocardia is differentiated from

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Streptomyces species by its failure to grow well on gelatin and to hydrolyze casein, and its ability to produce acid from glucose and glycerin but not from other carbohydrates. According to Conant and Rosebury (1948), N. asteroides is the only species of Nocardia pathogenic for laboratory animals. Drake and Henri ci (1943) inoculated guinea pigs and rabbits intravenously, and R u n y o n (1951) recommended mice, in which intraperitoneal injection results in abscesses in the peritoneum or the mesentery and on the surfaces of abdominal organs. Strauss and Kligman (1951) recommended the inclusion of gastric mucin in the inoculate. Georg et al. (1961) reported that many strains vary in pathogenicity, and found animal inoculation impracticable for routine diagnosis, preferring to rely on the morphological and biochemical characteristics of the fungus for its identification as a pathogen. IMMUNOLOGY It appears certain that animals and man must inhale Nocardia asteroides frequently from its widespread source in soil, but diagnosable infection occurs only rarely. Whether this infrequency of occurrence is owing to the natural immunity possessed by all normal individuals, or to the development of a specific immunologic resistance in response to the infection so quickly and efficiently as to keep most cases subclinical until spontaneously healed, and therefore never recognized, is not yet clear. Drake and Henrici (1941) prepared an extract of cultures of this fungus, calling it asteroidin, and showed that infected rabbits and guinea pigs developed the ability to react strongly to its intracutaneous injection. T h e y stated that this reactivity was due to protein-like material contained in the antigen, which would make difficult any comparisons with the results of intracutaneous use of coccidioidin and similar materials from other deep mycotic organisms, for these are largely polysaccharides. N o mass testing of human beings, either normal ones or those infected with N. asteroides, has been attempted, and until such testing is carried out with this material, as well as with purified polysaccharide extractives, the question must remain in doubt. Schneidan and T y n e s have recently reported new antigens which may prove useful. Whether or not there are specific circulating antibodies in the serum of patients with nocardiosis is not yet clear, judged by the conflicting reports available; nor has their relationship, if any, to immunity or to the extent of the infection been established. THERAPY T h e treatment of nocardiosis has seldom been successful, even though the fungus is sensitive to several antibacterial chemicals and antibiotics.

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Early diagnosis is the most imperative need, before extensive destruction of lungs and especially of brain tissue has occurred. Awareness of the possibility that the disease may be present, together with recent improvements in diagnostic laboratory techniques, should improve the prognosis. Sulfonamides are the favored drugs, among which sulfadiazene is important, maintained at a blood level of 9 to 12 mg percent or more over many months if necessary. Streptomycin, 2 grams daily in addition to the above, has been recommended. Penicillin has seemed helpful, although N. asteroides is resistant to it in culture. The effectiveness of penicillin in vivo probably results, as in actinomycosis, from its ability to suppress the concomitant bacterial element so often present, and indeed so often necessary to allow Nocardia to become pathogenic. Animal experiments suggest that aureomycin should also be of value. Under the protection and with the help of chemotherapy and antibiotics, surgical measures, such as incision and drainage or debridement, are useful. General supportive measures must be long continued to prevent relapse.

Bibliography Beckmeyer, W. J. 1959. Nocardiosis: report of a successfully treated case of cutaneous granuloma. Pediatrics, 23:33. Burbank, B., T . G. Morrione, and S. S. Cutler, i960. Pulmonary alveolar proteinosis and nocardiosis. Amer. J. Med., 28:1002. Cross, R. M., and C. H. Binford. 1962. Infections by fungi that are commonly primary pathogens. Lab. Invest., 11:1103. Eppinger, H. 1890. Über eine neue Pathogene Cladothrix und eine durch sie hervorgerufene Pseudo-tuberculosis. Wien Klin. Wochschr., 3:221. Goldberg, S. A. i960. A case of systemic infection due to Nocardia asteroides. J. Albert Einstein Med. Center, 8:148-152. Gordon, R., and W. A. Hagen. 1936. A study of some acid-fast actinomycetes from soil. J. Infect. Diseases, 59:200. Gordon, R. E., and J. M. Mihm. 1962. Identification of Nocardia caviae. Ann. N.Y. Acad. Sci., 98:628. Larsen, M. C., H. D. Diamond, and H. S. Collins. 1959. Nocardia asteroides infection: a report of 7 cases. Arch. Intern. Med., 103:712. Strouse, C. D. 1961. Brief recording: fatal exfoliative dermatitis after sulfamethoxypyridazine. New Engl. J. Med., 264:39. Webster, B. H. 1956. Pulmonary nocardiosis. Amer. Rev. Tuberc. Pulmón. Diseases, 73:485. Welsh, J. D., E. R. Rhoads, and W. Jacques. 1961. Disseminated nocardiosis involving spinal cord. Arch. Intern. Med., 108:73.

12 Mycetoma

INTRODUCTION STRICTLY DEFINED, the term "mycetoma" designates any tumor produced by fungi, especially of the filamentous type, but it is here used to mean a special form: a chronic sinus-producing fibrotic swelling, yielding pus which contains granules, localized to one area of the body (usually one foot, or, less frequently, one hand), and resulting from intracutaneous inoculation of any one of a large group of widely different fungi. It is preferable to other names often considered synonymous, such as Madura foot or maduromycosis, which imply a limitation based on geography or on the genus of the causative fungus.

HISTORY First reported from the region of Madura in India by McGill in 184a, and confirmed by Colebrook in 1846, the disease became known as Madura foot. In i860 Vandyke Carter called it mycetoma, and classified it accord150

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ing to the different-colored granules that were produced. In 1905 Brumpt showed that several different fungi can cause the same clinical picture. Langeron included in the term "mycetoma" the cases caused by Actinomyces and Nocardia, as well as those caused by fungi whose hyphae are much larger in diameter. ETIOLOGY Instead of listing the various fungi capable of causing mycetoma (see section on mycology, below), this paragraph takes up other etiologic factors of even greater importance. As in actinomycosis and nocardiosis, an alliance between a fungus and any one of several species of bacteria seems to be necessary to develop pathogenic powers sufficient to cause mycetoma. In addition, trauma often appears to lower resistance in a localized area enough to allow the infection to start. Mycetoma sometimes results from the activities of fungi ordinarily not considered to be pathogenic at all, emphasizing the importance of localized (or even systemic) nonmycotic diseases in lowering resistance. Inadequate nutrition and hygiene are not infrequently contributory. DISTRIBUTION Mycetoma is highly concentrated in some geographic regions, mainly tropical and subtropical, throughout the world, with occasional cases reported from many other areas. Abbott reported an extremely high incidence from the Sudan region in Africa, where 1,231 cases were admitted to hospitals in a period of thirty months, with many more treated in clinics. Most of the infections in Africa are caused by higher fungi, whereas in Mexico and South America Nocardia brasiliensis predominates. T h e disease is much more frequent in males than in females, and attacks particularly those in the middle adult years. There is no indication of additional susceptibility because of race or skin color. Farmers frequently become infected. EPIDEMIOLOGY Mycetoma is acquired by direct inoculation of one of the causative fungi through the skin by injuries, usually sustained by walking barefoot in the soil. If such inoculations were alone capable of invariably causing the disease, however, it would be very much more common. In view of the almost universal distribution of several of the potentially causative fungi in the soil, and the large number of persons in the world not accustomed to wearing shoes, it must be concluded that there are other more important epidemiologic factors, such as those suggested above (see section on etiology).

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CLINICAL

CHARACTERISTICS

Mycetoma conforms roughly to the clinical pattern described for actinomycosis, except for variations caused by special proclivities of each causative fungus and by the anatomy of the limbs as contrasted with the cervical, thoracic, or abdominal regions predominantly involved in actinomycosis. T h e usual picture is a painful and tender foot, so severely swollen as to have lost much of its usual contour; the sole is often convex instead of flat. Studded over the surface are many openings of draining sinuses exuding pus in which granules are easily seen. Localized areas of inflammation and extra swelling represent newly forming acute abscesses, while other areas are subsiding to become healed by dense fibrosis. T h e infection extends deep into the tissues, and involvement of the bones by direct extension through the periosteum is common, especially in infections caused by certain fungi. T h e granules typical of mycetoma may be white, yellow, red, pink, or black, according to the particular fungus involved, and sometimes reach the size of s to 3 mm. Certain fungi produce granules with structures so definitive that an experienced mycologist can often identify the varieties most commonly occurring in his own area by microscopic examination alone. Although most cases of mycetoma involve the foot or the leg, the same type of disease may affect buttock, hand, forearm, shoulder, or chest wall. In fact, from the clinical standpoint, cases of mycetoma merge indistinguishably with actinomycosis and nocardiosis when these diseases involve the chest wall, for example. Some cases of mycetoma in the foot have been caused by Actinomyces israelii, and some by Nocardia asteroides, although others so reported were probably due to a variant of N. asteroides called N. caviae. Radiographs of bony involvement show punctate areas of osteoporosis without sequestration, and periostitis with new bone formation. Three cases have been reported which revealed a dense mass of new bone formation at the base of the skull. PATHOLOGY T h e characteristic gross pathology of mycetoma is that of a region in which acute purulent abscesses are continuously developing, burrowing in several directions and eventually discharging to the surface, leaving draining fistulous tracts which finally subside to be replaced by fibrosis. T h e process may last many years, in fact throughout most of a lifetime, without injuring the general health of the patient beyond causing varying degrees of incapacitation of the involved limb.

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Histopathologically, the characteristic granules are seen, each in the center of an acute abscess, surrounded by a dense accumulation of polymorphs in all stages of disintegration, around which there is a zone of fibroblasts and granulation tissue rich in capillaries. Macrophages are common, as are giant cells of the multinucleated type in some forms while rare in others. DIFFERENTIAL

DIAGNOSIS

Mycetoma presents a picture so typical as to be easily diagnosed, especially in the regions of highest incidence. It is occasionally duplicated, of course, by other mycotic infections disseminated to the limbs by the bloodstream, particularly coccidioidomycosis. MYCOLOGY N o problem in medical mycology is more complicated than that presented by mycetoma. T h e organisms responsible possess a wide spectrum of pathogenic powers. Certain species, such as Monosporium apiospermum, Madurella mycetomi, and Nocardia brasiliensis, have been proved responsible for large numbers of cases, whereas numerous other species of fungi were each recovered in only one or a very few instances, and in many of them it is doubtful whether they were truly the cause, or were only concomitantly present in the diseased tissues as saprophytes. In the latter group there is much added confusion because of inadequate mycologic study, resulting in a tremendous nomenclature designating as new species many organisms that almost certainly should be included as simple variants in well-established categories. It is well to emphasize that proof of the pathogenicity of one of these unusual organisms must rest on the completeness of the details submitted with the report, including evidence that the fungus was obtained not only once, but several times, from widely separated areas of the disease and deep enough to make it appear plausible that it exists wherever the disease exists, and that all other possible causes for the pathology at hand were diligently sought without success. A l l too frequently a clinician accepts a disease as of fungal origin on insufficient evidence, and points all therapy in that direction for months, only to discover eventually, and often too late, an underlying neoplastic or metabolic process much more important to the future of the patient. Only the more commonly encountered organisms are discussed here. A n excellent guide to the laboratory phases of mycetoma may be found in the Laboratory Manual for Medical Mycology (1963), by Ajello, Georg, Kaplan, and Kaufman. As mentioned elsewhere, Actinomyces israelii occasionally duplicates

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the picture of mycetoma (as does Nocardia asteroides, in all probability, although some cases attributed to it were apparently caused by a variant known as N. caviae). These organisms are not further dealt with in this chapter. In addition to these occasionally encountered actinomycetes, other fungi of this group, belonging to the genera Nocardia and Streptomyces cause mycetoma. Nocardia brasiliensis (Lindenberg) Castellani and Chalmers 1913 is often encountered in mycetoma, especially in Mexico, Central and South America, and Africa. It frequently and extensively involves bone, rendering treatment difficult without amputation. In tissues it forms soft white or yellowish granules up to 1 mm in diameter. In sections, the filaments are mildly acid-fast, but much less so than most strains of N. asteroides. Some strains closely resemble chromogenic mycobacteria. In culture N. brasiliensis grows slowly to produce wrinkled or folded, moist- or chalky-surfaced colonies of a yellow or light-orange color. It can coagulate milk and liquefy gelatin, but not casein, and does not metabolize paraffin. Microscopic examination of culture material reveals fine branching hyphae, 1 micron or less in diameter, often breaking up into bacillary fragments. Gram's stain and acid-fast stains are useful in identification. Streptomyces madurae (Vincent) MacKinnon and Artagavietia Allende 1956 (formerly called Nocardia madurae) occasionally causes mycetoma. It frequently produces extensive bony involvement. In tissues its granules are comparatively large, up to 5 to 7 mm in diameter, and are soft and white or yellowish. In culture the colonies develop moderately fast, and are cream-colored, pink, or red, with a shiny wrinkled surface which may later become powdery or chalky because of a thin layer of aerial mycelium. Microscopically, the hyphae are not acid-fast; they are 1 micron in diameter or less, occasionally bearing the tiny spherical conidia which caused the fungus to be moved from Nocardia into the genus Streptomyces. Streptomyces pelletieri (Laveran) MacKinnon and Artagavietia Allende 1956 (formerly called Nocardia pelletieri) is closely allied to 5. madurae as described above, except for some of its biochemical reactions. The grains produced in tissues are smaller, harder, and more highly colored, ranging from pink to red. In culture the colonies are also more highly colored, varying from red to violet. The hyphae are not acid-fast. Streptomyces somaliensis (Brumpt) MacKinnon and Artagavietia Allende 1946 (formerly Nocardia somaliensis) forms granules up to 2 mm in diameter in tissues, varying from yellow to brown, smooth and hard in consistency because of a cement-like substance that holds the hyphae together. In culture this fungus rather rapidly forms colonies which are cream-colored apd wrinkled at first but soon tend to acquire a light-brown aerial fuzz, and eventually to become darker brown or gray. Microscopic

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examination reveals the characteristic hyphae of the actinomycete group, which are less than 1 micron in diameter and not acid-fast, and sometimes produce chains of arthrospores. Streptomyces paraguayensis (Almeida) Conant 1947 produces blackish granules in tissue. In culture it yields smooth, soft, white centers with the periphery dark brown. Microscopically, it produces the same tiny filaments as others in the group, sometimes with characteristic sporulation. Allescheria boydii (Shear 1921) was shown by Emmons in 1944 to be the perfect ascomycetic form of Monosporium apiospermum (Saccardo 1911), but many strains never exhibit the perfect stage in culture. This fungus is one of the most common causes of mycetoma, particularly in the United States, although the total number of cases is not large, and has been isolated from soil and sewage (Ajello, 1956). It produces in tissues yellowish-white granules, the hyphae of which are wide, up to 10 microns in diameter, especially near the periphery, where the tips appear swollen into what may or may not be spores. On artificial media this fungus grows rapidly; it is white at first but soon turns a dirty gray or brown. When examined microscopically it reveals the conidia characteristic of Monosporium, consisting of light-brown, pear-shaped or oval, rather thickwalled spores up to 12 microns in length, borne singly at the tip of single or branched conidiophores, and at times along the sides of the hyphae. In some strains the perfect sexual ascocarps, up to 200 microns in diameter, may be found; on crushing they yield numerous delicate, thinwalled asci, each containing the usual eight oval ascospores somewhat resembling the conidia described above. In addition to mycetoma, this fungus has occasionally been reported as causing pulmonary infections, as well as corneal ulcers. Madurella mycetomi (Laveran) Brumpt 1905 frequently causes mycetoma, particularly in Africa but also in Asia and South America, and occasionally in North America, where some strains were given species separation by Gammel. It produces black grains in tissues, often as large as 5 mm or more; they are firm but not brittle as are the grains of Streptomyces somaliensis. Microscopically, the grains of M. mycetomi are seen to be composed of hyphae averaging 5 microns in diameter, and enlarging near the periphery of the granule. The larger hyphae have a brown coloration. In culture the colony grows slowly (better at 37°C), becomes wrinkled, then fluffy with mycelial cover, and is variable in color, from white to yellowish-brown. Chlamydospores up to 20 microns are formed frequently. Sometimes large, black, sclerotic bodies are formed almost a millimeter in diameter. Madurella grisea MacKinnon, Ferrada, and Montemayor 1948 is more commonly recovered in the Western Hemisphere. It forms small black grains in tissues, soft at first, but becoming hard and brittle on drying. The cultured colony grows slowly (better at room temperature) to pro-

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duce a tan or gray mycelium. T h e hyphae are small in diameter, between 2 and 5 microns, and sometimes appear to be made up of chains of rounded cells suggesting a budding process. N o other method of reproduction has been described. M. grisea may be differentiated from M. mycetomi by its ability to utilize sucrose, but not lactose. Phialophora jeanselmei (Langeron) Emmons 1945 has caused a few cases of mycetoma in the United States and the West Indies. In tissues it produces black grains showing many chlamydospores. In culture it develops slowly to produce a small heaped-up black colony, at first moist on the surface but later becoming covered with a woolly gray mycelium. In the early glabrous stages microscopic examination shows strands composed of a chain of apparently budding cells. T h e aerial mycelium consists of septate hyphae which produce elliptical conidia about 1 micron long from slender elongated phialides, without a flare at their terminal openings. In addition to the more common fungi responsible for mycetoma described above, the disease has been attributed at times to various species in the genera Indiella, Glenospora, and Cephalosporium. Mycetoma has also been caused occasionally by several species of Aspergillus (and its variant Sterigmatocystis) and Penicillium. T h e discovery of an unusual organism in this disease calls for the services of the most experienced mycologist available. Animal inoculation is seldom serviceable in mycetoma; the clinical picture of this disease is not reproducible and many of the organisms are not pathogenic for the usual species of laboratory animals. DIFFERENTIAL

DIAGNOSIS

Mycetoma may be differentiated from elephantiasis, lymphedema, or swollen feet or hands attributable to other causes by the presence of draining sinuses and abscesses, as well as by evidence of invasion of the bone. Chromoblastomycosis does not penetrate so deeply as mycetoma, and produces surface ulcerations and heaped-up fungating masses. Neoplastic processes offer difficulty at times, especially if saprophytic fungi have colonized in the involved tissues and yield fungal cultures on artificial media. Other deep mycoses as well as granulomatous diseases, such as tuberculosis, yaws, or syphilis, may be differentiated by laboratory procedures. W h e n typical, the picture of mycetoma is usually clinically diagnostic. IMMUNOLOGY Because members of so large a group of fungi bearing little relationship to one another are capable of causing mycetoma, it is not surprising that

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its immunologic features are poorly understood. Its relatively rare occurrence among the many thousands of persons who contact such fungi from their natural sources indicates either a low grade of pathogenicity or the possession by the normal host of a high degree of natural resistance. Both of these features are undoubtedly important in holding down the incidence of the disease. T h e former is conclusively confirmed by the failure to duplicate the disease in its entirety by animal inoculations of the causative fungi, even when many species of animals have been used. T h e size of the inoculum may be important, as well as the depth to which the organisms are carried. It is likely that the extent of the accompanying trauma is influential. Although not so important nor so consistently present as in actinomycosis caused by Actinomyces israelii, an alliance between a fungus and one or more species of bacteria which is capable of conferring a degree of pathogenicity possessed by neither organism alone is indicated in many cases. Lowered host resistance is probably the most significant factor in mycetoma. T h e vast majority of cases occur in persons in low-income groups who are often poorly nourished in proteins and vitamins needed for resistance, and who never wear shoes. These factors, combined with total lack of cleanliness and medical attention, either domestic or professional, adequately explain the susceptibility of poorer people to mycetoma. There is less need to consider important the presence of a concomitant systemic disease such as diabetes or lymphoblastoma, as in many other deep fungus infections, but it is sometimes a factor. In coccidioidomycosis and North American blastomycosis (and perhaps in histoplasmosis), it has recently been shown that direct intracutaneous inoculation of the causative fungi into persons previously not infected by these organisms produces a chancriform syndrome, closely resembling the usual form of sporotrichosis, rather than a chronic, localized disease. This type of response has only rarely been reported for the organisms causing mycetoma. Why it does not occur more frequently is difficult to explain. Perhaps the immunologic resistance of the patient is not sufficient to produce it, or the patient may have been previously altered immunologically by the inhalation of the specific spores. It has not been established that there are cases so mild as to guarantee spontaneous recovery; whenever the diagnosis is established, vigorous treatment is therefore indicated. There have been a few attempts to utilize antigens extracted from the fungi that cause mycetoma in testing procedures, both by intracutaneous inoculation and by complement-fixation and precipitin serologic reactions, but most of these experiments have been inconclusive. Gonzdlez-Ochoa, after extensively investigating cases of mycetoma in Mexico caused by Nocardia brasiliensis (the most prevalent causative organism in that region), concluded that antigens specific for that fungus may serve in tests

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helpful in diagnosis, prognosis, and therapy. Using a purified polysaccharide derived from N. brasiliensis by González-Ochoa and Baranda (1953), he demonstrated precipitins and agglutinins in the serums of animals previously inoculated with the fungus, either alive or dead. T h e r e were cross reactions with similar materials derived from Nocardia asteroides and Mycobacterium tuberculosis, but usually in lower titer. In infected patients González-Ochoa could not demonstrate precipitins at all; he could demonstrate agglutinins irregularly, and not in correlation with the clinical course of the disease. Complement fixation was more useful, being positive in more than half of the cases, and the titer was higher (up to 1:256) when the disease was extensive or chronic and the patient's general condition was poor; in mild cases the reaction was usually negative. Skin tests with purified polysaccharide on patients with mycetoma caused by the same specific fungus yielded positive reactions of the delayed tuberculin type. T h e lack of such reactivity was associated with a bad prognosis, and a high degree of response, with a favorable one. Reactivity appeared in one case coincident with clinical improvement. González-Ochoa concluded that there are many similarities with the interpretations so much better established in coccidioidomycosis and histoplasmosis, and that the same basic immunologic pattern is probably followed by many different fungous diseases. Bojalil and Zamora (1963) prepared a purified polysaccharide from N. brasiliensis which revealed precipitins in patients with mycetoma caused by this organism. One fraction was specific and failed to react with other diseases such as leprosy, tuberculosis, and mycetoma caused by N. asteroides, whereas another fraction reacted with all these diseases. Bojalil and Zamora also utilized a purified protein derived from N. brasiliensis for intracutaneous testing, finding it of value in diagnosis. THERAPY T h e treatment of mycetoma is often disappointing, partly because extensive involvement has usually occurred before medical attention is obtained, and partly because the drugs presently available are comparatively inefficient. W i t h many widely different varieties of infecting fungi to deal with, it is almost inevitable that one drug cannot be used for all of them. In the earliest stages, when only a papule is present, excision is simple and effective if sufficiently radical; flooding the wound with tincture of iodine is suggested. Until recently, in extensive cases, especially when bone was involved, amputation well above the site of the lesion was the only method. Some drugs recently discovered are active in vitro against several of these .fungi, but they have thus far not been clinically so successful as hoped for.

P L A T E 28. Mycetoma (maduromycosis): clinical and mycologie aspects. Upper, middle, and lower left: mycetoma of foot caused by Nocardia brasiliensis. Upper right: mycetoma caused by Monosporium apiospermum. Middle right : granule of M. apiospermum in tissue. Lower right : gross appearance of colony of M. apiospermum on Sabouraud's agar.

29. Mycetoma: clinical and histopathologic aspects. Upper left: involvement of left flank anteriorly by Nocardia brasiliensis. Lower left: same infection in buttock. Upper right: N. brasiliensis, chronic infection of knee. Upper middle right : Actinomyces israelii granule in tissue (H & E x 100). Lower middle right and lower right : N. brasiliensis granules in tissue (H & E x 100). PLATE

P L A T E 30. Candidiasis (moniliasis): cutaneous lesions. Caused by Candida albicans. Upper left: oral moniliasis or thrush, more common in infancy. Middle left: perleche, not always monilial in origin. Lower left: severe moniliasis of submammary areas; note satellite rounded lesions, less likely in intertrigo. Upper right: so-called erosio interdigitalis blastomycetica, usually involving web between third and fourth fingers. Lower right: monilial vulvovaginitis.

PLATE JI. Moniliasis, aspergillosis and rhinosporidiosis: pathology. Upper left: Candida albicans in kidney, fatal liasis in infant (PAS X400). Lower left and upper aspergillosis of lung (PAS x 200). Middle and lower rhinosporidiosis in nasal polyp.

histomoniright: right:

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Diamidinodiphenylamine (May and Baker 938) inhibits Madurella mycetomi and M. grisea in vitro, but its systemic use has been disappointing in such infections. T h e drug p, p'-sulfonyldianiline is reported to have helped one case of M. grisea infection; 2, 2'-dihydroxy-5, 5'-dichlorodiphenyl sulfide (Novex) is also active in vitro. Abbott quotes Cockshott (1957) as advocating local injections of the above drugs on alternate days as deeply and extensively into the lesions as possible, accompanied by wide surgical debridement. This treatment is followed by daily irrigation of the granulating base with p, p'-sulfonyldianiline solution, and by oral medication for eighteen months. For infections caused by Nocardia brasiliensis the consensus is that sulfonamide therapy is still the preferred approach, and so far there is little evidence that amphotericin B is likely to replace it. Diaminodiphenyl sulfone (p, p'-sulfonyldianiline, DDS) in oral dosage of 100 to 200 mg daily was long the drug of choice, but had to be continued for a long period, even for many years. Gonzdlez-Ochoa reported that some cases were benefited by the same drug suspended in oil in 20 percent concentration and injected locally into the lesions, alone or combined with oral therapy. Recently sulfadimethoxine* and sulfamethoxypyridazinef (2, 4-dimethoxy-6-sulfanilamide-1, g-diazene) have gained popularity, and are even considered likely to become the preferred treatment. T h e dosage recommended by different authorities varies from 0.5 to 1.5 gm daily for two to six months or longer. T h e former drug has caused thrombocytopenic purpura, myocarditis, and aplastic anemia. Early in its career griseofulvin was tested clinically by Latapi and Lavalle (Latapi et al., 1959) with encouraging results, but relapses have considerably dampened the initial enthusiasm. In infections caused by Nocardia madurae and N. somaliensis, streptomycin is suggested, beginning with a heavy dosage of 3 gm daily for three weeks, followed by 2 gm daily and then by 1 gm daily for similar intervals, with tetracycline added during the first two weeks. We have observed one case of maduromycosis caused by Monosporium apiospermum which responded neither to griseofulvin nor to amphotericin B; it did not even respond to the latter by massive perfusion of the leg while isolated from the general circulation (Newcomer), nor to several other drugs including pregnenolone, diamidinodiphenylamine, streptomycin, sulfonamides, and penicillin. Little is known of the efficiency of drugs for infections caused by the fungi less commonly encountered in mycetoma, some of which are ordinarily regarded as entirely nonpathogenic saprophytes. Some of these organisms are inhibited in vitro by amphotericin B or even by griseofulvin, which may indicate therapeutic trials. * Madribon®, Hoffman La Roche. •(• Midicel®, Parke Davis.

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Bibliography Bojalil, L. F., and B. Medina. 1959. Acción de diversos agentes quimioterapeúticos sobre el crecimiento de algunas especies de Nocardia. Rev. Latinoamer. Microbiol. (Mexico). Vol. 2, no. 1. Bojalil, L. F., and A. Zamora, 1963. Precipitin and skin tests in the diagnosis of mycetoma due to Nocardia brasiliensis. Proc. Soc. Exptl. Biol. Med., 113:40. Carrión, A. L., M. S. Hutner, H. M. Nadal, and M. E. Belaval. i960. Maduromycosis: an unusual case with a description of the causative fungus. Arch. Dermatol., 82:371. Courtois, Deloot, and V. Thys. 1954. Nine cases of maduromycosis in the Belgian Congo caused by Allescheria boydii, Monosporium apiospermum and Nocardia madurae. Ann. Soc. Beige Méd. Trop., 34:371-395. Destombes, P., and G. Segretain. 1962. Fungal mycetoma: histological and cultural characteristics. [In French.] Arch. Inst. Pasteur (Tunis), 39:273. Dubois, C. 1962. Cure without amputation of a black-granule mycetoma. [In French.] Ann. Dermatol. Syphil. (Paris), 89:355. Feiger, J. W. 1963. Mycetoma: review of the literature. Military Med., 128:762. Gammel, J. A. 1927. T h e etiology of maduromycosis. Arch. Dermatol. Syphil., 15:241. Ghosh, L. M., N. C. Dey, and D. Panja. 1950. Madura foot. Ind. Med. Gaz., 85:288. González-Ochoa, A. 1958. Tratamiento del micetoma actinomicósico por la injección local de la diamino-difenil-sulfona. Rev. Inst. Salubr. Enferm. Trop., i8(March):4i. . 1962. Mycetomas caused by Nocardia brasiliensis, with a note on the isolation of the causative organism from soil. Lab. Invest., 11:1118. González-Ochoa, A., and F. Baranda. 1953. A cutaneous test for diagnosing mycetoma caused by Nocardia brasiliensis. [In Spanish.] Rev. Inst. Salubr. Enferm. Trop., i3(March):i89. González-Ochoa, A., J. Shiels, and P. Vásquez. 1952. T h e action of 4, 4'-diaminodiphenyl sulfone on Nocardia brasiliensis. [In Spanish.] Gac. Méd. México, 82:345. González-Ochoa, A., and A. Vásquez Hoyos. 1953. Serological relationships of the principal pathogenic Actinomycetes. [In Spanish.] Rev. Inst. Salubr. Enferm. Trop., i3(March):i77. Latapí, F. i960. Micetom. In Handbuch der Hautausschlag und Geschlechtskrankheiten. Berlin: Jadassohn, Springer J. Latapí, F., and P. Lavalle. 1959. El empléo de las sulfonas en los micetomas. Mem. 3d Congr. Iber.-Latin-Amer. Dermatol., Mexico. P. 203. Latapí, F., P. Lavalle, J. Novales, and Y. Ortiz. 1959. Griseofulvina en micosis cutáneas y profundas: nota preliminar sobre resultados terapéuticos en un caso de micetoma por N. brasiliensis y en una de esporotricosis por S. schenckii. Dermatol. Rev. Mexicana, 3:34. MacKinnon, J. E. 1951. Los agentes de maduromicosis de los géneros Monosporium, Allescheria, Cephalosporium, y otros de dudosa identidad. An. Fac. Med. Montevideo, 36:153.

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. 1962. Mycetomas as opportunistic wound infections. Lab. Invest., 11:1184. MacKinnon, J. E., et al. 1948. Madurella grisea: a new species of fungus producing the black variety of maduromycosis in South America. [In Spanish.] Bol. Inst. Hig. Montevideo, 2:126. Macotela-Ruiz, M. E., and F. Mariat. 1963. On the production of experimental mycetomas by Nocardia brasiliensis and Nocardia asteroides. [In French.] Bull. Soc. Pathol. Exot., 56:46. Magana-Lozano, M. i960. El empléo de las sulfonamidas en el tratamiento de los micetomas. Estudio de la flora asociada: comunicación de 7 casos. Rev. Méd. Hosp. Gen. México, 23:223. Mariat, F. 1963. On the geographic distribution and incidence of mycetoma agents. [In French.] Bull. Soc. Pathol. Exot., 56:35. Niño, F. L., R . S. Freire, and P. Salica. 1962. Maduromycotic mycetoma in the province of Chaco: clinical and mycologic study. [In Spanish.] Rev. Asoc. Méd. Argentin., 76:359. Rey, M., R. Baylet, and R . Camain. 1962. Current data on mycetoma, apropos of 214 cases in Africans. [In French.] Ann. Dermatol. Syphil. (Paris), 89:511. Schmitt, J. A., R . J. Zabransky, A. S. Janidlo, and J. E. Parsons. 1962. Experimental maduromycosis in the laboratory mouse. Mycopathologica, 18:164. Vipulyasekha, S., and S. Vathanabhuti. i960. Treatment of nocardial mycetoma with sulphamethoxypyridazine. Brit. J. Dermatol., 72:188.

3

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Candidiasis (Moniliasis)

INTRODUCTION C A N D I D I A S I S is a fungous infection which usually remains superficially confined to the skin and mucous membranes, but is occasionally capable (in particularly susceptible individuals) of causing lesions in viscera which are serious to life. It is usually attributable to one species of fungus, Candida albicans.

HISTORY In 1839 Langenbeck discovered fungi by microscopic examination of scrapings from the mouth of an infant suffering from thrush. Gruby (1842) confirmed this finding, and Robin (1843) named the organism O'idium albicans. Candidiasis thus is a close competitor of favus as the earliest human fungous disease to be discovered. Schamberg studied a fatal case of thrush in 1915. In 1927 Castellani delineated bronchopulmonary moni165

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liasis, and classified yeastlike fungi according to their fermentation reactions. Joaquim and Polayes reported endocarditis in 1940. T h e advent of corticosteroid therapy and antibacterial antibiotics has caused a marked increase in serious forms of candidiasis by rendering the recipients abnormally low in resistance. ETIOLOGY It is not accurate to ascribe candidiasis entirely to the activities of C. albicans, because the fungus is probably contacted frequently by most human beings without causing any trouble whatever. It is presumably not pathogenic for normal areas of normal persons, but should be classed as an adventitious pathogen, able to superimpose its deleterious effects on tissues rendered abnormal by any of several known factors, and possibly by others as yet unrecognized. (For further discussion of this subject, see the section on immunology in this chapter.) DISTRIBUTION Candidiasis has no geographical limitation, although the cutaneous forms occur more frequently in climates inducing excessive perspiration. T h e fungus is almost a normal inhabitant of the intestinal tract, so that man carries it with him wherever he is in the world, ready and waiting for an opportunity to cause trouble. In regions of the world where the diet is high in carbohydrates, the intestinal tract contains the fungus more often than in other geographic areas. Lewis and Hopper found that its incidence in the intestinal tract increases with the age of the person. Candidiasis is thus properly termed an endogenous infection. T h e mouths of infants are particularly susceptible, but the incidence of cutaneous forms increases with age. T h e r e is no hypersusceptibility because of race or skin color. EPIDEMIOLOGY Beyond the factors already mentioned, and others better discussed under immunology, little need be said here. Under certain circumstances the disease must be classed as transmissible from person to person. Penile lesions occur from vaginal contact, and there have been outbreaks of thrush in nurseries which are probably extensive enough to be called epidemics. CLINICAL

CHARACTERISTICS

Candidiasis occurs in a variety of well-delineated clinical forms. It is often evident that there are factors resulting in lowered resistance in localized areas, many of them mechanical in nature, which are even more important

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etiologically than the activities of the fungus. In the following section, therefore, the clinical appearance alone is described, and other important features are reserved until the later discussion of therapy, where they are of paramount importance. Oral candidiasis Commonly called thrush, this disease is most often found in newborn infants. They probably become infected during passage through the vagina, where the fungus exists in a high percentage of women, especially in the latter months of pregnancy, often without causing any symptoms. This manner of infection is much more likely than implantation of the fungus in the babies' mouths from other infants by faulty nursery technique. Thrush is seldom serious except in weak or premature infants, but it is often stubbornly resistant to treatment because frequent feedings high in carbohydrates are essential at that time of life. The tongue, the soft palate, the buccal mucosa, and at times all mucous membranes of mouth and pharynx are covered by discrete or confluent patches of creamcolored or gray nonadherent membrane, not so deep as that of diphtheria, but often painful and easily induced to bleed. Oral candidiasis is also troublesome in the aged, especially when chronic disease causes malnutrition or other forms of lowered general resistance. It is frequently severe in diabetes and during long-term treatment with corticosteroids or orally administered antibiotics. Perleche This term designates inflammation and some erosion at the corners of the mouth; Candida albicans is often, but not invariably, found in these lesions. In most cases there is no other oral involvement, and usually there is evidence of a very important mechanical cause, equivalent to intertrigo in other areas of the body (see discussion under immunology). Intertrigo This troublesome and at times severe dermatosis involves the groins, the intergluteal cleft, the perineum in general, the axillary and submammary areas, and the umbilicus, and is likely to result whenever two skin surfaces are held in contact continuously or for long hours at a time without opportunity for aeration and the evaporation of sweat. The usual cause is obesity, which in really severe form also furnishes sufficiently deep creases in the neck or beneath overhanging abdominal masses. The wearing of tight girdles may cause trouble even in mildly obese persons. C. albicans is often present in such areas, but so are bacteria; or there may be no important microorganisms present at all, but simply maceration due to perspiration. Often there is chemical irritation, caused in part by the degeneration of the urea of the perspiration into ammonia

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by bacterial action, as occurs in diaper rash in infants. Diabetics are especially likely to have moniliasis in these areas because of heightened glucose levels in the perspiration. A careful evaluation of all contributing causes must precede attempts at treatment, and laboratory procedures are mandatory, but it is often possible to diagnose the presence of a monilial factor by the fact that the disease may extend its activities far beyond the surfaces of skin actually in intertriginous contact. In such peripheral locations moniliasis causes rounded lesions, some of which have not yet coalesced. They present an unusual type of scaling, consisting of a collarette of keratinized epidermis still attached at the periphery of the lesion, while the central part has already been lost. Vesicles are common in such borders as well. Sometimes, particularly in diabetics seriously out of control, the disease may spread until large areas of the body surface become involved. Intertrigo also occurs between the toes, especially if they are short and thick, furnishing little or no interspaces for aeration, or even in most normal individuals when tight occlusive shoes are worn in hot weather. Sometimes the same condition is observed in finger webs, particularly in obese women with short thick fingers who have their hands frequently in contact with water or food materials. Because the ring finger is more difficult to separate from the middle finger by the small muscles of the hand, this interspace is often involved; when affecting this area, the disease has been given the imposing name "erosio interdigitalis blastomycetica." Vulvovaginal moniliasis This form of the disease occurs frequently, particularly in diabetics and pregnant women, owing to the increased sugar content of secretions and urine or to a glycogen-like material in the vaginal mucosa. Candida albicans is often found in this location in entirely asymptomatic individuals, but it may cause extreme irritation and pruritus in the entire area. Perianal moniliasis Moniliasis may occur in the anal area without intertrigo, especially after the oral ingestion of antibacterial antibiotics of the broad-spectrum type. T h e bacterial flora of the intestinal tract is strongly suppressed by such substances, permitting the unaffected Candida so often present to have unopposed use of nutritive materials. It has even been stated that these antibiotics directly nourish the fungus. Considerable pruritus results from this infection. Paronychia and onycholysis These ailments have been linked with moniliasis, but as often as not the lesions do not contain C. albicans at all; sometimes only bacteria are

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found, or both bacteria and the fungus may be present. The role of bacteria as secondary invaders has been emphasized by Stone and Mullins (1962), who found from three to five different species in each of five cases. It is evident that the real cause here is almost entirely mechanical. Paronychia may be acute or chronic. In the acute form it consists of a painful and tender erythematous swelling of the eponychial tissue, either localized to one edge or all around the base of the nail. Only one nail may be involved, but more often several or all of them are affected; the disease occurs much more commonly in fingernails than in toenails. Persons who frequently have their hands in water, or in contact with food materials, are most often affected. Cooks, salad makers, fruit peelers in the cannery industry, pie makers, dishwashers, and laundry workers are especially susceptible. In chronic paronychia there is only slight erythema and little swelling or pain, but tenderness on pressure is common. The eponychium has separated from the dorsal surface of the nail, and the hiatus thus formed extends proximally, often almost to the point of origin of the nail, about 4 to 5 millimeters. This mechanical feature is of the utmost importance in the selection of therapy (to be discussed later). A very useful probe for revealing the depth of the groove may be devised by grasping an ordinary applicator stick between the two hands, each thumb and forefinger holding only an inch at the end. If the stick is bent carefully, beginning with the arc of a large circle and gradually decreasing its diameter until the stick breaks, the grain of the wood from which these sticks is made is usually sufficiently angulated to result in a flat, sharp-pointed, and yet somewhat rounded tip. This tip, easily inserted into the paronychial groove without causing pain, demonstrates to the operator, as well as to the patient, the depth to which the abnormal separation has extended, usually 4 or 5 millimeters. The probe is even more important in the succeeding weeks of therapy, for as healing progresses and the nail grows distally, it is easy to demonstrate that the depth of the groove is progressively diminishing; cure will be heralded one or two weeks before it is complete by showing that the probe can be inserted only 1 or 2 millimeters. Onycholysis This disease occurs alone as well as in conjunction with paronychia, and often from the same causes. It consists of a separation of the nail from its underlying bed, beginning distally and extending proximally for varying distances, sometimes completely to the point of origin of the nail. The separation may be caused by nail lacquer or its remover, especially by what have been called permanent forms of these preparations. In some persons the chemicals actually penetrate the nail plate and cause inflammation and separation underneath. There is seldom discomfort in the usual form of onycholysis, but few women like to tolerate its appearance;

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if untreated, the infection usually works its way proximally until the nail becomes a "flail" and is either torn away accidentally or has to be removed. Proper treatment (to be discussed later) can prevent this result.

Monilial granuloma This very rare form of moniliasis often begins in early childhood as oral thrush, and ultimately tends to concentrate on hands, feet, face, and scalp. Hauser and Rothman (1950) reported one case, and cited thirteen from the literature. In contrast with the clinical types described above, in which the disease process always remains superficial, monilial granuloma is characterized by an inflammatory reaction extending deeply into the corium and forming granulation tissue resembling that seen in deep mycoses. Covering the lesions are large encrustations, some assuming the proportions of cutaneous horns which are broken off from time to time, leaving bleeding granulomatous bases. In Hauser and Rothman's case, the mouth and the pharynx were severely affected, and it was presumed that the larynx was also involved because the patient's voice was hoarse. T h e eyes and the nasal mucous membrane remained free, as did the genital and anal areas. T h e disease had been present continuously from the age of eleven months, and many types of antifungal treatment had helped only to lessen its severity. No systemic contributory cause could be discovered until the patient, when ten years old, was brought to the hospital in diabetic coma. He died of diabetes a few years later. Wilson made two comments concerning this case. First, it is difficult to understand why Candida albicans would select areas like the hands and the scalp for severe involvement without affecting its usually preferred regions—groins, perianal area, umbilicus, and eyes—unless a congenital ectodermal defect was present in the former, rendering them hypersusceptible. Second, the fungus C. albicans almost certainly recognized the patient as an incipient diabetic long before the laboratory tests for the disturbed carbohydrate metabolism which is called diabetes could do so. Danbolt and Closs (1943), describing a disorder somewhat similar to the above, called it acrodermatitis enteropathica. Caused presumably by dietary deficiencies or colitis, it is more common in infants than in older persons. T h e skin lesions are often loaded with Candida, but it is acting only as a secondary invader, for considerable success is attained in combating this disease by the oral administration of diiodohydroxyquinoline, which is not an efficient Candida opposer. Pulmonary moniliasis This usually culosis creased

form of the disease was formerly seldom reported, and then in association with some other pulmonary disease, such as tuberor coccidioidomycosis. Recently, however, its incidence has inmarkedly because of the extensive use of antibiotics, corticosteroids,

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and antimitotic agents to keep patients alive by controlling, but not curing, an otherwise fatal disease. It is always difficult to separate the pulmonary symptoms actually caused by Candida from those of the other underlying disease. Monilial endocarditis T h i s form resembles subacute bacterial endocarditis, with evidence of growths on the heart valves. Most cases have occurred in "mainliners" addicted to narcotics used by intravenous injection, who do not adequately sterilize the needles and syringes. Disseminated candidiasis W h e n any of the viscera or the central nervous system is invaded by elements of the fungus carried in the bloodstream, disseminated candidiasis results. It is usually a terminal event superimposed upon another fatal illness. PATHOLOGY In the vast majority of cases, Candida albicans acts as do the dermatophytes, confining its activities to the outer layers of the epidermis, but it also affects the mucous membranes. In histopathologic sections of biopsy material from skin or mucous membrane, the fungal elements can be seen, both hyphae and budding cells. T h e y are usually well delineated by H & E stain, but the results are much better with the Gridley or the PAS method. In the pulmonary or disseminated types, the pathologist may make the diagnosis from the autopsy material. There is often little or no evidence that the body is offering any resistance to the infection. T h e monilial granuloma form is interesting to study in tissue section; it is marked by hyperkeratosis, acanthosis, pseudoepitheliomatous hyperplasia, and a granulomatous infiltrate, composed of leucocytes, plamsa cells, epithelioid cells, and giant cells, extending deep into the corium. In monilial endocarditis, vegetations on the heart valves are usually loaded with elements of Candida. DIFFERENTIAL

DIAGNOSIS

T h e superficial forms of candidiasis must be differentiated from intertrigo, bacterial infections, and dermatophytosis. Such differentiation can rarely be accomplished by visual means alone. Direct microscopic examination of bits of tissue from active borders is often sufficient, because C. albicans differs from the dermatophytes by producing, in addition to hyphal elements, small budding spores called blastospores, about 2 to 3 microns in

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diameter, in clusters resembling grapes. T h e only other fungus obtainable from skin with which it could be confused is Malassezia furfur from tinea versicolor, whose blastospores are considerably larger and whose hyphal fragments are always short and curved. T h e locations in which M. furfur is found, and the clinical picture, are entirely different from those associated with moniliasis. It is much better to trust direct microscopic examination than to rely upon cultures in deciding how much of any disease that is present can be correctly attributed to Candida albicans. A culture of this fungus can be obtained so often from skin or mucous membrane where it is causing no trouble at all, that the mere fact of its recovery does not signify that it is acting importantly as a pathogen. A culture can also be obtained from actual lesions if only a very few Candida cells are present, not enough to cause much of the disease. Only if direct microscopic examination reveals large numbers of the typical cells of C. albicans in the diseased tissue should the diagnosis be accepted as candidiasis alone. T h e same caveat applies also to vaginal involvement, oral lesions, and the examination of sputum. It is useless to trust cultural methods for sputum examination; even direct mounts are sometimes misleading, for Candida can grow rapidly on such specimens in the few hours they may remain at the bedside or in the laboratory before being examined. In monilial granuloma the lesions may suggest bromoderma or iododerma, but the history of the case is usually helpful. Acrodermatitis enteropathica is accompaned by diarrhea and malnutrition. There can be no suggestions for the reliable differentiation of disseminated candidiasis from other diseases, because it is always associated with one or more of the latter. All sorts of combinations of symptoms and signs are possible. It cannot be overemphasized that some other pathologic condition is always associated with moniliasis, either localized or systemic. Even the unexpected discovery of the presence of Candida should immediately inaugurate an intensive search for such other factors. Diabetes is frequently first diagnosed because of such an event. MYCOLOGY Candidiasis is usually caused by a single species of fungus, Candida albicans, but other members of the genus Candida may occasionally be responsible, principally in vaginal infection and in endocarditis. Treatment is usually successful without interspecific differentiation, but difficult cases should be subjected to careful mycologic study. Morphology and cultural characteristics are seldom sufficient, and fermentation reactions must be determined. Only the type species C. albicans is discussed here; some details concerning the others may be found in Part IV of this volume.

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Candida albicans (Robin) Berkhout 1923 grows moderately rapidly in culture, at first producing a white or slightly cream-colored colony suggesting a yeast or bacteria, with a smooth moist surface only mildly elevated. Later, rootlike projections are sent downward into the agar at one or more points; they are much coarser than any similar radiating elements produced by bacteria, and to the experienced eye almost certainly indicate the identity of C. albicans. Microscopic examination of bits of material taken from these areas of penetration into the agar reveals hyphae 4 or 5 microns in diameter with large clusters of budding cells (blastospores), borne just proximal to the crosswalk. Species of Candida other than albicans seldom produce such large clusters of blastospores, and it is usually easy to accept the identification. Cultures on cornmeal agar medium reveal an additional feature almost exclusively possessed by C. albicans, the production of rounded, thick-walled macroconidia or chlamydospores from 8 to 12 microns in diameter, borne at the tips of enlarged hyphae. Animal inoculation is seldom needed, but C. albicans is virulent for mice and rabbits. Intravenous inoculation results in the production of miliary abscesses in most visceral organs, notably the kidney. IMMUNOLOGY In the preceding paragraphs reference has been made repeatedly to the fact that Candida albicans is not considered pathogenic for normal areas of the bodies of normal human beings, but that it simply attacks secondarily when some other disease lowers the normally complete resistance, either by local or systemic influence. Excessive perspiration, especially in obese persons, or in areas of skin kept too closely in apposition by confining girdles, brassieres, or shoes, is likely to produce localized conditions favorable to the growth of C. albicans. Eczematous forms of dermatitis may also be similarly attacked. T h e same sort of intertrigo may be considered the actual cause of perleche, involving the corners of the mouth, and it is instructive to discuss this relationship in detail. Slowly during advancing years, or rapidly when accompanying severe weight loss, the facial tissues become lax and the cheeks sag enough to form deep creases at the corners of the mouth. T h i s feature is often accentuated because full dentures are worn for years without change; the alveolar ridges gradually shrink and flatten, causing the tip of the nose to be brought ever closer to the point of the chin. In some patients this change may amount to almost half an inch, resulting in a significant addition to deep commissural creases. If the patient sleeps without his dentures, the process is assisted during the night. T h e r e is constant drooling and moistening of these creases with the tongue. T h e result is the equivalent of intertrigo elsewhere in the body, and it is not surprising to find Candida happily active, although not the primary cause

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of the disease. Antifungal treatment alone cannot cure this disorder completely. Riboflavin, in doses of 5 mg three times daily, has been recommended and seems helpful, but whenever possible the mechanical causes should be combated. The most helpful measure is the acquisition of new dentures in which the teeth are set much farther from the surface of the denture which is in contact with the alveolar ridge, thus increasing the distance from nose to chin toward the former normal span. In paronychia and onycholysis the equivalent of intertrigo is the most important cause of the pathologic process. In the former the eponychium is separated mechanically from the dorsal surface of the nail, and the resulting crease often extends proximally to the point of origin of the nail. It is impossible to cause these two surfaces, once so torn apart, to heal together; all that can be hoped for is to prevent them from being torn farther apart. Attempts to clean out the interstice mechanically, or to force semisolid substances such as ointments into it, simply widen the separation. The disease process itself also tends to keep the hiatus from being closed, and must be combated by antifungal and antibacterial substances, which should be in solution rather in ointment form. It is very important not to allow any food material to enter the interstice, and thereby nourish bacteria and fungi. Even an occasional contact with fruit juice, soup, or dishwater may furnish plenty of nutritive elements to support microorganisms. If all the above factors are properly controlled, the natural distal growth of the nail, together with its eponychial fold, will repair the gap in about six or eight weeks. Any departure from the prescribed regimen will prolong the time of healing in direct proportion. Several systemic factors are known to favor monilial infection, the principal one being diabetes mellitus. Vitamin deficiencies, particularly of the B group and especially of riboflavin, have been implicated, as have lymphoblastomas and hypoparathyroidism. The oral administration of broad-spectrum antibacterial antibiotics favors the development of candidiasis, especially around the anal area, often accompanied by vaginal and oral lesions, and sometimes spreading over wide areas. Long-term administration of corticosteroid hormones, especially in high dosage, favors candidiasis, and has been the principal cause of its recent increasing incidence. No doubt the disease for which the hormone is being given is often more responsible than the therapy for the generalized lowering of resistance, but it is impossible to separate one from the other. The belief that diabetes is a much more complicated disease than is represented by its long-known alteration of glycogen-glucose metabolism under the influence of insulin has recently gained currency. Almost certainly, some change in carbohydrate metabolism precedes (possibly for many years) the development of clinically diagnosable diabetes, even when such diagnosis is assisted by glucose tolerance curves and by "loading" techniques with glucocorticoids. For at least ten years Wilson has been an

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adherent of the school of thought that credits the fungus Candida albicans with greater ability to diagnose this prediabetic diathesis, or syndrome, than we possess with all our laboratory aids. One of the best examples is the case reported by Hauser and Rothman (1950). T h a t child was severely and continuously affected with candidiasis from the age of eleven months to the age of ten years, at which time diabetic coma occurred; diabetes was then diagnosed for the first time, even though the patient had been closely observed and carefully tested for a long time in an excellent research institution. We have observed a number of persons who suffered from recurrent, and at times very intractable, moniliasis for several years, and eventually developed diabetes. Even more interesting is the unilateral involvement so often seen in Trichophyton rubrurn infection (discussed in the immunology section of chap. 18), which suggests that the prediabetic factor may be active in certain localized areas of the body for years, while absent in all others, and hence that it may operate on a cellular or tissue level rather than as a systemic factor. Intracutaneous testing with extracts of cultures of Candida is seldom helpful, for many normal persons prove to be reactive. Apparently the percentage of persons showing this reactivity increases with age; the response may therefore result from a subclinical infection acquired at some time in life and may persist indefinitely thereafter. Testing for it may thus have the same status as coccidioidin and tuberculin testing. Only if the hypersensitivity (to high dilutions) is extreme has there been any suggestion of therapeutic assistance through desensitization in the presence of moniliids. Numerous attempts to correlate the presence of complement-fixing antibodies, precipitins, or agglutinins in the serum of patients suffering from moniliasis with the clinical course of the disease have not proven helpful in diagnosis or prognosis. THERAPY This section cannot serve as a guide to treatment without consideration of the foregoing discussion of clinical characteristics, and especially of immunology, for these factors are of far greater importance than the selection of drugs. As soon as candidiasis is diagnosed, or even suspected, the search for another infection should be the clinician's first obligation, for the discovery of another disease and its elimination or amelioration will benefit the patient more than antifungal medication. A l l measures against intertrigo already discussed should be carried out. Treatment for any internal disease that is present, most frequently diabetes, is imperative. Methylrosaniline chloride (gentian violet) in x percent aqueous solution has always been a popular remedy for intertriginous moniliasis and, in the opinion of many dermatologists, is still the most effective drug for the

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acute phases of the disease. It should not be used more than once daily, and usually not more than two or three times weekly, lest it cause ulcerations by becoming more concentrated on the skin and in the exudate than the 1 percent strength in which it is applied. Because several cases of deep ulcerations of this type were produced by the use of the drug by patients at home, Nelson Paul Anderson and Wilson long ago nicknamed the remedy "gentian violent." The maintenance of absolute dryness at all times by aeration, and the liberal use of nonmedicated, nonscented talc without starch content, are mandatory. The talc should be applied as frequently as is necessary to keep the area dry, even as often as once an hour. T o wash away excess talc that becomes caked in combination with sweat or exudate, plain water or, better, diluted "alibour" solution should be used, and the skin should be dried immediately thereafter. At this point an antifungal drug is helpful, either nystatin in a vanishing-cream base, very thinly applied and allowed to dry thoroughly, or amphotericin B in lotion or in vanishing-cream form, similarly used. Talc should then at once be liberally applied. This regimen usually brings considerable relief within a few days, but hot weather, obesity, or other factors may make complete cure a long and difficult process. Gokhale (1963) recommends a new antifungal antibiotic, derived from Streptomyces primprina in India, for cutaneous moniliasis. Paronychia is almost always successfully treated if the precautions discussed in the section on immunology are carefully noted. Because most women object to applying a highly colored, odiferous medication to their fingernails continuously for the several weeks needed for cure, we recommend the use of a colorless drug, thymol, 4 percent in chloroform, which does not have an objectionable odor. The chloroform seems to dilute and float out some of the moisture present in the interstice and then itself evaporate, leaving the interstice dry. The drug should be used at least three times daily and, in addition, every time the nails have been in water. It is applied by bringing a drop of the solution in contact with the interstice and letting it run in by capillarity only. Onycholysis yields to the same procedure, but it is necessary to clip away the overlying nail plate as far proximally as it has been loosened in order to maintain the necessary cleanliness and dryness. Attempts to avoid such removal because of appearance usually delay the cure indefinitely. Ray (1963) recommends 15 percent sulfacetamide solution in 50 percent alcohol twice daily after debridement. In monilial granuloma and moniliasis, either pulmonary or disseminated, intravenous amphotericin B is the treatment of choice (see chap. 3 for details of its use). It has replaced oral potassium iodide, ethyl iodide by inhalation, and aerosols with antifungal drugs, but it is too early to evaluate the long-term results.

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GEOTRICHOSIS In a few recorded instances a disease similar to oral, intestinal, or bronchopulmonary candidiasis has been attributed to a different fungus, Geotrichum candidum Link 1809. T h i s organism is a common saprophyte on fruit, vegetables, and dairy products, and is frequently found in soil. It is also commonly present in the human gastrointestinal tract, usually only in the role of a saprophyte. It is therefore often difficult to assess the part it plays in causing disease. In sputum specimens, as well as in culture, G. candidum forms septate branching hyphae which break up into arthrospores, cylindrical to barrel-shaped, or sometimes elliptical, and about 4 by 8 microns in size.

Bibliography Benham, R . W . 1941. Certain monilias parasitic on man: their identification by morphology and agglutination. J. Infect. Diseases, 49:183. Coffey, C. M., M. A . Everett, and F. R . Kay. 1961. Amphotericin B in disseminated cutaneous candidiasis (granulomatous). Arch. Dermatol., 83:1014. Comaish, M . B., B. Gibson, and C. A . Green. 1963. Candidiasis: serology and diagnosis. J. Invest. Dermatol., 40:139. Engel, M. F. 1961. Monilial granuloma with hyper-gamma-globulinemia. Arch. Dermatol., 84:192. Finnerud, C. W . 1929. Perlèche: clinical and etiologic study of 100 cases. Arch. Dermatol. Syphil., 20:454. George, B. S., and O . A . Plunkett. 1948. Dissociation in Candida albicans. J. Invest. Dermatol., 10:327. Gokhale, B. B. 1963. Hamycin: a new antifungal antibiotic. Arch. Dermatol., 88:558. Gruby, D. 1842. Sur une espèce de mentagre contagieuse d'un nouveau cryptogame dans le racine des poils de la barbe de l'homme. Compt. Rend. Acad. Sci. Paris, 15:512. Hasenclevere, H. F., W . R . Mitchell, and L. Loewe. 1961. Antigenic studies of Candida. J. Bacterid., 82:574. Hauser, F. V., and S. Rothman. 1950. Monilial granuloma. Arch. Dermatol. Syphil., 61:297. Hazen, E. L., and R . Brown, i960. Nystatin. A n n . N.Y. Acad. Sci., 89:1. Hopkins, J. G . 1932. Moniliasis and moniliids. Arch. Dermatol. Syphil., 25:599. Jansen, G. T . , C. J. Dillaha, and W . M. Honeycutt. 1963. Candida cheilitis. Arch. Dermatol., 88:325. Kagelman, T . P., D. J. Cripps, and E. R . Harrell. 1963. Candida granuloma with epidermophytosis. Arch. Dermatol., 88:150. Kingery, L . B., and C. H . Thienes. 1925. Mycotic paronychia and dermatitis in fruit canners. Arch. Dermatol. Syphil., 11:186.

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Kligman, A. M. 1950. Aids in technique in the identification of Candida albicans. J. Invest. Dermatol., 14:173. Littman, M. L., M. A. Pisano, and R . M. Lancaster. 1958. Induced resistance of Candida species to nystatin and amphotericin B. Antibiot. Ann., 1957-58. Maibach, H. I., and A. M. Kligman. 1962. T h e biology of experimental human moniliasis (Candida albicans). Arch. Dermatol., 85:233. Marquezy, R . A., I. Bertrand, C. Bach, J. Hartmann, and J. Godet-Guillam. i960. Moniliasis of the central nervous system. [In French.] Ann. Pediatr. (Paris), 36:197Moore, M. 1948. Granulomatous moniliasis resembling blastomycosis. Mycopathologia, 4:272. Ray, L. F. 1963. Onycholysis. Arch. Dermatol., 88:181. Riddell, R. W. 1961. Precipitins in the diagnosis of fungous infections. Brit. J. Dermatol., 73:326. Robin, C. 1843. Histoire naturelle des végétaux qui crossent sur l'homme et sur les animaux vivants. Paris. Robinson, H. M., Jr. 1954. Moniliasis complicating antibiotic therapy. Arch. Dermatol. Syphil., 70:640. Rosenthal, A. L. 1963. T h e effect of amphotericin B lotion on cutaneous moniliasis. Arch. Dermatol., 87:270. Schamberg, J. F. 1915. A case of extensive fatal thrush, with involvement of skin and secondary infection of mother's breasts. Arch. Pediatr., 32:617. Sorenson, L. J., E. G. McNall, and T . H. Sternberg. 1959. T h e development of strains of Candida albicans and Coccidioides immitis which are resistant to amphotericin B. Antibiot. Ann., 1958-59:920. Spencer, M. C. 1963. Clinical limitations of experimental cutaneous moniliasis. Arch. Dermatol., 88:925. Stone, O. J., and J. F. Mullins. 1962. Chronic paronychia. Arch. Dermatol., 86:324. Sutton, R. L., Jr. 1938. Gentian violet as a therapeutic agent. J. Amer. Med. Assoc., 110:1733. Taschdjian, C. L., G. B. Dobkin, L. Caroline, and P. J. Kozinn. 1964. Immune studies relating to candidiasis. II. Experimental and preliminary clinical studies on antibody formation in systemic candidiasis. Sabouraudia, 3:129. Vieu, M., and G. Segretain. 1959. Contribution a l'étude de Geotrichum et Trichosporum d'origine humaine. Ann. Inst. Pasteur (Paris), 96:421. Whittle, C. H., and G. A . Gresham. 1963. Paronychia experimentally produced. J. Invest. Dermatol., 40:267.

14

Chromoblastomycosis

INTRODUCTION is a chronic fungous disease almost always limited to the skin and subcutaneous tissues, characterized by warty, ulcerated and crusted, fungating lesions, often papillomatous. It is caused by one of several closely related species of dark-brown to grayish-black fungi. T h e name is admittedly not appropriate. T h e disease (the mycosis) itself is not colored, although the fungi are, both in the tissues and in culture. T h e organisms do not reproduce in the tissues by an actual budding process, as suggested by the combining form "blasto-." T h e r e is a tendency to call the disease "chromomycosis," but at present it seems better to retain the well-established longer name. CHROMOBLASTOMYCOSIS

HISTORY In 1914 Rudolph published observations on a case of chromoblastomycosis from Brazil. Lane and Medlar, reporting a case from Boston in 1915,

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named their fungus Phialophora verrucosa. In 1920, however, Pedroso and Gomes revealed that one of four cases they were describing from Brazil, which were caused by a similar fungus, had been under their observation since 1911. It seems, therefore, that Pedroso should be given credit for the discovery of chromoblastomycosis. T w o years later Terra, Torres, Fonseca, and Area Leao reported another case, and Carini added two more in 1924, suggesting the name now in use for the disease. T h e first case outside the Western Hemisphere was found by Montpellier and Catanei in Algeria. It soon became evident that the fungi causing these clinically similar cases showed considerable morphologic variation. In 1933 Wilson, Hulsey, and Weidman observed the second case in the United States, believing the fungus identical with that causing the first case, reported by Lane and Medlar; Martin, Baker, and Conant found another case in 1936 caused by an organism identical with that from the early cases in Brazil. Carrion began writing about chromoblastomycosis in 1933, adding much to our knowledge of the clinical syndrome as well as to the mycology of the various species of fungi. Additional mycologic details were contributed by Emmons and, more recently, by Silva (i960). ETIOLOGY As intimated above, several fungi cause chromoblastomycosis, all closely enough related to have created wide differences of opinion as to how they should be classified and named. (This subject is discussed in the section on mycology.) DISTRIBUTION Chromoblastomycosis has been found in South, Central, and North America, the West Indies, Europe, Africa, Japan, and Australia. It is most common in C u b a and Brazil. T h e r e is a strong predominance of males over females, almost 20 to 1, among those afflicted. A distinct tendency toward concentration in certain geographic areas has been noted, and rural districts furnish most of the infections. Persons in close contact with soil and vegetation are much more often infected than others. Chromoblastomycosis occurs predominantly in people between the ages of twenty and fifty; the extremes of three and seventy-six have been recorded. T h e r e is no apparent susceptibility owing to race or skin color. EPIDEMIOLOGY T h e majority of cases occur on the feet or on the legs below the knees under circumstances suggesting that the causative fungi are inoculated

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directly through the skin by means of injuries sustained while walking barefoot in contact with the soil. T h i s explanation, however, does not cover the numerous cases involving other areas of the body. T h e clinical appearance and the course of the disease in these cases are so nearly identical with their counterparts in the chronic cutaneous form of North American blastomycosis as to suggest that the skin may become involved by dissemination of the fungi from a primary focus elsewhere. (This subject is discussed in more detail in the section on immunology.) There are several species of fungi almost universally distributed in nature which cannot be distinguished by morphology from the pathogenic organisms capable of causing chromoblastomycosis, although recent studies of their nutritional requirements and biochemical reactions may clarify this subject. A dead leaf that has been lying on the ground for more than a few days is almost always infected by Hormodendrum (Cladosporium). In 1937 Conant found that the species of fungus which commonly causes blue or gray staining of new lumber, previously called Cadophora americana, is morphologically identical to one of the pathogens for chromoblastomycosis, Phialophora verrucosa. As such fungi are contacted very frequently by man, other factors must be sought to explain the comparative rarity of the actual infection. Even the accompaniment of trauma is insufficient explanation. Perhaps poor nutrition and hygiene in the host are the most important factors. There is no instance of direct transmission from man to man or from animals to man. CLINICAL

CHARACTERISTICS

Chromoblastomycosis is almost always limited to the skin and subcutaneous tissues. Although it is usually accepted that the disease begins at the point where the fungi were inoculated through the skin, an adequate case history indicating the truth of this theory is frequently absent, and the disease is seldom observed in its early phases. A papule or pustule, persisting for a long time before slowly enlarging and becoming ulcerated, has been described as the primary lesion in some cases. Verrucous lesions form by direct extension, as well as by implantation some distance away, or by lymphatic spread, but for some poorly understood reason the process tends to remain localized in the originally infected limb or area. (See discussion in section on immunology.) Eventually, large fungating, everting, verrucous masses protrude 1 or 2 centimeters above the level of the skin, often attached by a narrow pedicle. These lesions are secondarily invaded by bacteria, and form purulent foul-smelling crusts. Perhaps more from this bacterial element than from the fungus itself, lymphatic stasis and often elephantiasis result. Carrion has described the cutaneous lesions of chromoblastomycosis as nodular, tumorous, verrucous, plaquelike, and cicatricial. T h e newest and

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smallest lesions are nodular, moderately elevated, soft, pink to violaceous growths with smooth, warty, or scaly surfaces. Later they are transformed into tumors, papillomatous, lobulated masses partly or wholly covered with dirty-gray epidermal debris, purulent crusts, and horny particles. On the foot these masses grow very large, and resemble small cauliflowers. Verrucous lesions are predominantly hyperkeratotic and may resemble common warts. Less common than the above are slightly elevated flat plaques, exhibiting various degrees of infiltration, usually seen higher up on the leg. In many lesions the periphery continues to expand while the center becomes healed, resulting in a soft, noncontractile scar with annular, arciform, or serpiginous contour. Chromoblastomycosis develops very slowly. T h e infected tissue is easily traumatized and bleeds readily. There may be pruritus, and sometimes pain, the deeper tissues are almost never involved, except for the lymphatics, and these are affected probably only because of the concomitant bacterial invasion, even to regional adenitis. Metastasis, although it has been reported, must be very rare, and there are usually no systemic symptoms. In a few cases the central nervous system has been involved with fungi capable of causing chromoblastomycosis, sometimes in patients with typical skin lesions, and hence the disease is considered to have been disseminated hematogenously from them. In some instances, however, no skin lesions have been present, suggesting the possibility of dissemination from an unrecognized focus in internal organs, probably the lungs. PATHOLOGY The gross pathology of chromoblastomycosis is in conformity with the clinical picture; the process is little deeper than is visible from the exterior. It is a typical granulomatous process. Histopathologically, the epidermis is thickened by hyperplasia, often irregular enough to suggest carcinoma, especially to the uninitiated. There is marked hyperkeratosis, and the corneous layer is much distorted. Polymorphonuclear leucocytes are scattered throughout the epidermis, often concentrated in small abscess masses entirely within it. In the cutis, the reaction is granulomatous, with a varied cellular infiltrate composed of lymphocytes, polymorphs, plasma cells, and monocytes, accompanied less frequently by eosinophiles, Russell bodies, and giant cells. Some areas may be tuberculoid, others may be abscessed. There is often considerable evidence of fibrosis, leading to healing eventually in very old areas. All doubt as to the specificity of this reaction is easily dispelled by discovering in microscopic sections the very distinctive fungous cells. They are usually rounded, sometimes crescent-shaped, bodies occurring singly

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or united together in small or large masses, each cell being from 8 to 15 microns in diameter, with thick walls possessing a deep-yellow to brown coloration not easily confused with any other entity. T h e y may occur in the center of microabscesses, in giant cells, or free in the tissues. Sometimes short hyphal strands can be seen, also characterized by browncolored walls, especially close to the surface of the tissue where the fungus is evidently attempting to grow almost as it does in artificial culture. Despite a vague resemblance to the budding process so evident in Blastomyces and Cryptococcus infections, it is accepted that these masses are not produced in that way, but are called sclerotia. DIFFERENTIAL

DIAGNOSIS

In its earlier stages chromoblastomycosis may be confused with North American blastomycosis (especially in individuals with lightly pigmented skin), tuberculosis verrucosa cutis, bromoderma, iododerma, leishmaniasis, tertiary syphilis, and yaws. W h e n well developed, however, it presents a most distinctive clinical picture, and is almost impossible to confuse with any other entity. MYCOLOGY T h e species of fungi which cause chromoblastomycosis are all closely related and the resulting disease shows no differences. T h e clinician can therefore make his diagnosis reliably by the microscopic appearance of the pathognomonic light-brown, rounded bodies, either in the exudate from lesions or in tissue sections. For exact identification of the organism, experienced taxonomic mycologists must examine the cultures. These fungi utilize three basic methods of spore production, any one of which may cause the organism in question to be placed in a certain genus. T h e principal difficulty arises because many strains are not satisfied with a single method, but demonstrate two or even all three. In 1936, because of this confusion, Negroni suggested that a special genus, Fonsecaea, be created especially for these organisms which would allow such deviations. In 1947, after studying the group intensively, Carri6n and Silva agreed with Negroni's nomenclature. Emmons, however, recommended that the organisms be included in the genus Phialophora, as first named by Medlar, considering the differences insufficient for classification in separate genera. Emmons, though not convinced of the necessity of having several separate species within the genus, considers it convenient to continue to do so for the present at least. A l l the fungi of chromoblastomycosis yield the same dark-colored colonies, showing black color through the reverse of the agar and slowly forming a heaped-up mass, either smoothly rounded or folded on the

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surface of the medium, topped by a velvety covering of short mycelial strands appearing dark gray or slightly brownish-gray. These hyphae produce conidia by one or more of three methods, each of which typifies botanically a well-established genus among fungi. Cladosporium (formerly Hormodendrum) produces rounded or oval brownish conidia in branched chains from the enlarged tips of specialized conidiophores. T h e chain is formed by a budding process carried on successively by the most distal cell of the chain; when it produces two buds, a branched chain eventuates. W h e n broken apart each spore shows a prominence at each end, indicating where it was attached to its neighbor. Phialophora produces flask- or vaseshaped conidiophores called phialides, from the open tips of which oval brownish spores are extruded singly, only to adhere rather strongly by a gelatinous material while other spores are being produced, eventually forming a spherical mass of as many as a hundred of them, adhering together. These spores do not show protrusions at their ends as in Cladosporium. Acrotheca designates spore production all along the sides and at the tip of a swollen, club-shaped conidiophore; the spores rarely produce budding, and thus form only short chains. Silva (1958) has shown that certain characteristics of the medium on which the fungi are grown, as well as the temperature, may influence the type of sporulation produced. O n the basis of the predominating type of sporulation, Emmons recommends the following classification which, at the time of this writing, seems to be the most appropriate. T h e subject is covered excellently in Medical Mycology, by Emmons, Binford, and Utz (1963). Phialophora verrucosa Medlar 1915 exhibits almost exclusively the phialophora type of sporulation. Phialophora (Cladosporium, formerly Hormodendrum) pedrosoi (Brumpt 1922) n. comb. Emmons 1944 utilizes predominantly the Cladosporium type of sporulation, usually limited to short chains when compared with the common saprophytic species of Cladosporium, but occasionally revealing one or both of the other forms, as in Phialophora and Acrotheca. Phialophora compactum (Carrion 1935) n. comb. Emmons 1944 is said to grow more slowly to produce spores in the same manner as P. pedrosoi, but the spores are globular instead of oval and tend to form closely packed short chains. Phialophora dermatitidis (Kano 1937) n. comb. Emmons, though said to be highly variable as to its method of spore production, is more closely allied to Phialophora verrucosa than to other species. In the early stages of its growth it produces buds similar to those of the saprophyte fungus Pullularia pullulans. Cladosporium carrionii Trejos 1954 is the only known fungus causing chromoblastomycosis in Australia; it has also been found in South Africa

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and Venezuela. It sporulates exclusively in the Cladosporium manner, producing long chains similar to those of the common saprophytic species of Cladosporium (Hormodendrum). IMMUNOLOGY It is usually assumed that all cases of chromoblastomycosis originate by primary inoculation of the causative fungi through the skin by means of wounds contaminated by soil. This explanation seems plausible for the cases that begin in the foot or the leg, and perhaps for those that begin in the hand, but is not fully satisfactory when body surfaces usually covered by clothing are involved. With this reservation in mind, and recalling the resemblances in clinical picture and course between this disease and chronic cutaneous North American blastomycosis, now thought to be caused by dissemination from a previously unrecognized primary focus in the lungs instead of by primary cutaneous inoculation, Wilson suggested that this process may also explain some cases of chromoblastomycosis. In Cuba, where the disease occurs frequently, Baquero sought evidence of pulmonary lesions in early cases of cutaneous chromoblastomycosis. Although unable to find conclusive evidence by X-ray studies, he did succeed in culturing from the bronchial washings of four early cutaneous cases fungi indistinguishable from those obtained from the skin lesions; with them he duplicated Koch's postulates by inoculating the cultural material into normal skin and producing typical lesions. Further evidence pointing in this direction was his discovery that skin testing with an antigen extracted from such fungi revealed a higher percentage of positive reactors among the normal population in endemic areas than in other areas. This finding suggests that chromoblastomycosis may exist in a mild pulmonary form, clearing spontaneously with subsequent immunity, as do coccidioidomycosis and histoplasmosis, and possibly also North American blastomycosis. T h e chancriform syndrome typical of sporotrichosis and occasionally of other deep mycoses must be very rare in chromoblastomycosis, although there are a few suggestive cases. It is evident that the human body is well able to resist the disease, which often continues to expand slowly in the skin for as long as twenty years without harming the general health of the patient or becoming disseminated into internal organs. In sporotrichosis, coccidioidomycosis, North American blastomycosis, and histoplasmosis, the normal human body offers a similarly high degree of resistance, and in these diseases primary inoculation of the fungi into the skin has been observed to result in the chancriform syndrome. It is admitted that this picture may not develop if the patient has been previously infected by the same fungus or by one that is antigenically similar, perhaps even by

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another route, such as inhalation, with a resulting unrecognized pulmonary infection. Subsequent intracutaneous inoculation in such persons would find the patient's immunologic or allergic responses altered from the normal by his previous experience, and the chronic cutaneous form might thus evolve. Serologic tests in both man and animals, using extracts of the causative fungi as antigens, have been reported by Balina et al. (1932), Martin (1936), and Conant and Martin (1937). Cross reactions have been observed among the various species of fungi, indicating once again their close genetic relationship. So far there has been no success in correlating such reactions with the clinical course of the disease so as to aid in diagnosis or prognosis. Nor has there been substantiation of the speculation that some factor capable of lowering the natural resistance of the host, either locally or- systemically, must be present to allow these frequently contacted fungi to cause actual disease so infrequently. It is interesting to note Symmers' (i960) report of a brain infection occurring in a patient long treated for polyarteritis with corticosteroid hormones. THERAPY T h e treatment of chromoblastomycosis is not entirely satisfactory. T h e consensus is that the most effective treatment is oral administration of potassium iodide, to highest tolerance as outlined for sporotrichosis, combined with calciferol, 600,000 units orally or intramuscularly once weekly. T h e calcium and phosphorus levels of the blood must be watched, and joint pains and swelling may require temporary cessation of the calciferol. Baquero has reported good results from local application of calciferol in an ointment containing about 2 million units per ounce, with 10 percent sulfur, 6 percent benzoic acid, and 3 percent salicylic acid. T h e fungi causing chromoblastomycosis are relatively resistant to amphotericin B, at least at the levels usually obtainable in the blood by intravenous administration, leading Costello et al. (1959) to use it by injection locally into the lesions. T h e drug was suspended 5 mg per liter in 2 percent procaine solution, and 7 cc were injected into the lesions once weekly for three months. Complete clearing was obtained and at the time of the report there had been no relapse for fourteen months. A closely intravenous administration, leading Costello et al. (1959) to use it by inthe infected area is not large it may be surgically removed, and replaced by a full-thickness skin graft. Some cases exhibiting scattered papillomatous fungating lesions can be cured by curettage and desiccation. Often the case is so far advanced before medical attention is sought, and elephantiasic swelling has so increased the patient's weight, that amputation is the wisest procedure.

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Bibliography A l - D o o r y , Y . , a n d M . A . G o r d o n . 1963. A p p l i c a t i o n of

fluorescent

a n t i b o d y pro-

cedures to the study of p a t h o g e n i c d e m a t i a c e o u s f u n g i . J. Bacteriol., 86:332. B a q u e r o , G . F. 1959. L a i n t r a d e r m a reacción c o n a n t í g e n o de

Hormodendrum

pedrosoi. B o l . Soc. C u b a n a D e r m a t o l . Sifil., i6(Dec.):go. B a q u e r o , G . F., a n d B . R . Lascay. i960. C u l t i v o d e l Hormodendrum

pedrosoi

d e l m a t e r i a l o b t e n i d o p o r l a v a d o b r o n c h i a l e n c u a t r o e n f e r m o s de

cromo-

blastomicosis. B o l . Soc. C u b a n a D e r m a t o l . Sifil., i7(Sept.):g9. B e e r m a n , H . , a n d L . M . S o l o m o n . 1963. A m p h o t e r i c i n B a n d electrodesiccation f o r chromoblastomycosis. A r c h . D e r m a t o l . , 87:492. B i n f o r d , C . H . , G . Hess, a n d C . W . E m m o n s . 1944. Chromoblastomycosis: r e p o r t of a case f r o m c o n t i n e n t a l U n i t e d States a n d a discussion of classification of the causative f u n g u s . A r c h . D e r m a t o l . Syphil., 49:398. C a r r i ó n , A . L . 1940. T h e specific f u n g i of chromoblastomycosis. P u e r t o R i c o J. P u b l i c H e a l t h T r o p . M e d . , 15:340. . 1950. Chromoblastomycosis. A n n . N . Y . A c a d . Sci., 50:1255. C a r r i ó n , A . L . , a n d M . Silva. 1947. C h r o m o b l a s t o m y c o s i s a n d its etiologic f u n g i . A n n . C r y p t o g a m . P h y t o p a t h o l . , 6:20-62. Costello, M . J., C . P . de Feo, Jr., a n d M . L . L i t t m a n . 1959. C h r o m o b l a s t o m y c o s i s treated w i t h local infiltration of a m p h o t e r i c i n B solution. A r c h .

Dermatol.,

79:98D e Feo, C . P., a n d L . C . H a r b e r . 1959. C h r o m o b l a s t o m y c o s i s treated w i t h local infiltration of a m p h o t e r i c i n B solution. J. A m e r . M e d . Assoc., 1 7 1 : 1 9 6 1 . Guerrero-Santos, J. 1959. T r a t a m i e n t o q u i r ú r g i c o de la cromomicosis. 3d C o n g r . I b e r . - L a t i n - A m e r . D e r m a t o l . , M e x i c o . P. 181. I w a t a , K., a n d T . W a d a . 1957. M y c o l o g i c a l studies o n the strains isolated f r o m a case of chromoblastomycosis w i t h metastasis in the c e n t r a l n e r v o u s system. J a p a n e s e J. M i c r o b i o l . , 1:355. L a t a p í , F. 1959. C i t e d by O . R o d r í g u e z , Cromoblastomicosis: su t r a t a m i e n t o con calciferol. 3d C o n g r . I b e r . - L a t i n - A m e r . D e r m a t o l . , M e x i c o . P p . 1 8 2 - 1 8 9 . M a r t i n , D . S., R . D . B a k e r , a n d N . F. C o n a n t . 1936. A case of v e r r u c o u s dermatitis caused b y Hormodendrum pedrosoi (chromoblastomycosis) i n N o r t h Carol i n a . A m e r . J . T r o p . Med., 16:593. M o n t e m a y o r , L . de. 1949. E s t u d i o de las p r o p r i e d a d e s biológicas de varias cepas de h o n g o s p a t ó g e n o s causantes de l a cromomicosis. M y c o p a t h o l o g i a , 4:379. Puig-Fuentes, E. 1959. C i r u g í a d e r m a t o l ó g i c a d e cromoblastomicosis. B o l . Soc. C u b a n a D e r m a t o l . Sifil., i6(Sept.): 5 5 - 6 1 . R o d r í g u e z , O . 1959. Cromoblastomicosis: su t r a t a m i e n t o c o n calciferol. 3d C o n g r . I b e r . - L a t i n - A m e r . D e r m a t o l . , M e x i c o . P p . 182-189. Silva, M . 1957. T h e parasitic phase of the f u n g i of chromoblastomycosis: develo p m e n t of sclerotic cells i n v i t r o a n d i n vivo. M y c o l o g i a , 49:318. . 1958. T h e s a p r o p h y t i c phase of the f u n g i of chromoblastomycosis: effect of nutrients a n d t e m p e r a t u r e u p o n g r o w t h a n d m o r p h o l o g y . T r a n s . N . Y . A c a d . Sci., 2d ser., 2 1 : 4 6 - 5 7 .

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. i960. Growth characteristics of the fungi of chromoblastomycosis. Ann. N.Y. Acad. Sci., 89:17-29. Simerangco, S. A., and C. Halde. 1955. Chromoblastomycosis: first case in the Philippines. J. Philipp. Isl. Med Assoc., 31:117. Trejos, A. 1954. Cladosporium carrionii n. sp., and the problem of cladosporia isolated from chromoblastomycosis. Rev. Biol. T r o p . Univ. Costa Rica, 2:75112.

Wilson, J. W. 1958. Importancia de las enfermedades fungosas en inmunología. Bol. Soc. Cubana Dermatol. Sifil., i5(Dec.):ii5.

Phycomycosis (Mucormycosis)

INTRODUCTION "phycomycosis" was suggested by Emmons to designate an occasionally occurring human disease caused by fungi. T o o little is known or discoverable about these fungi to identify them accurately as to genus or species; they belong to the class of fungi known as Phycomycetes, whose principal characteristics are the almost complete lack of septa in the hyphae and the production of spores within an enlarged terminal sac called a sporangium. Most of the discrepancies occur because the fungal cause is discovered by the pathologist only by examining, microscopically, tissue sections from autopsy, at which time the only material available for other types of study has been formalinized and therefore cannot be used for initiating cultures. THE NAME

HISTORY Sluyter described pulmonary phycomycosis in 1847. Paltauf (1885) reported the disease disseminated to the brain. In 1903 Vuillemin observed 189

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T h e intermediate mycoses

a disease caused by a species of phycomycete, probably of the genus Absidia. Most of our present knowledge has been assembled recently from the writings of Gregory, Golden, and Haymaker (1943), Baker and Severance (1948), Baker (1956), Hutter (1959), Laudau and Newcomer (1962), and Straatsma and Zimmerman (1963). ETIOLOGY Although the term "mucormycosis" has long been used synonymously with the newer name "phycomycosis," species of the genus Mucor are not often involved. T h e most frequently encountered species belongs to the genus Absidia (to be discussed further under mycology); others belong to the genera Rhizopus, Mortierella, Basidiobolus, Mucor, and Cunninghamella. DISTRIBUTION Phycomycosis has been reported from many parts of the world. Apparently it has no geographic limitation, but it shows concentration in places where personnel are capable of making the diagnosis, where autopsies are customary, where severe dietary deficiencies exist, and where certain types of therapy for other systemic diseases, which render persons more susceptible to phycomycosis, are carried out. No age group is exempt, but children are particularly predominant among those affected. There appears to be no preponderance caused by sex or race. EPIDEMIOLOGY All the fungi that cause phycomycosis are commonly occurring saprophytes in nature, and are frequently encountered as contaminants in the mycology laboratory. As the fungi are doubtless contacted frequently by all human beings, they are not true pathogens, but rather opportunists, able to cause disease because of localized or systemic factors that lower tissue resistance. By far the most common of these factors is severe, uncontrolled diabetes, particularly its acidosis, for acidosis due to other causes, such as renal failure or diarrhea, is also often encountered as a causative factor. Prolonged intensive corticosteroid therapy is the next important factor; others are leukemia, lymphoblastoma, neoplasm, antibiotic administration, and extensive X-radiation. Severe gastroenteritis, malnutrition, tuberculosis, chronic hepatic or renal disease, extensive body burns, and congenital heart disease have also caused phycomycosis. As the causative fungi enter the body most frequently by inhalation of spores, the lungs are primarily involved; from them there is hematogenous dissemination, predominantly to the central nervous system. Localized

P L A T E 32. Chromoblastomycosis: clinical forms. Upper left: early initial lesion, probably primary cutaneous, but not chancriform. Middle left: chronic granulomatous type closely resembling clinically the usual form of North American blastomycosis. Lower left: verrucous lesion on sole. Upper and lower right: chronic form with multiple exuberant fungating projecting masses.

3 3 . Chromoblastomycosis: clinical forms and histopathology. Upper left: chronic granulomatous form resembling North American blastomycosis. Middle left: verrucous and nodular type. Lower left: histopathologic picture in chronic granulomatous form, showing intraepidermal microabscesses (H & E X 100). Upper right: masses of sclerotia in tissue (H & E x 200). Middle right: sclerotia in giant cell (H & E x6oo). Lower right: gross culture of Cladosporium pedrosoi, one of the fungi capable of causing chromoblastomycosis (and not inconsistent with the others). PLATE

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191

cutaneous lesions may develop from inoculation of the organisms into wounds or otherwise diseased areas of the skin. Infections may be acquired in the orbit or paranasal sinuses and may spread to the brain. T h e disease may appear to be endemic in certain regions, not because of a concentration of the causative fungi in nature, but because of the prevalence of a predisposing cause in the population (see section on distribution, above). CLINICAL

CHARACTERISTICS

Because phycomycosis is regularly superimposed on some other disease process, or occurs in the course of strenuous treatment for such a disorder, clinical separation of the two processes is always difficult. T h e infection often spreads with extreme rapidity, resulting in death in a few days. When, as occasionally happens, the fungi are discovered in tissue sections before any other disease has been diagnosed, an immediate and diligent search for the latter is mandatory, because successful treatment depends more upon its control than upon antifungal measures. Laudau and Newcomer (1962) have classified phycomycosis into cranialfacial, thoracic, abdominal-pelvic, and dermal types. In the first category, cerebral involvement has been recognized most frequently; except in infants, it has been accompanied by diabetes in 77 percent of the cases, usually with severe acidosis. Proptosis, ophthalmoplegia, fixation of the pupil of the eye, and absence of the corneal reflex may occur, together with signs of cranial nerve involvement. There may be ulceration and perforation of the palate and nasal septum. Headaches, with signs of increased intracranial pressure, suddenly appear as the disease progresses. Examination of cerebrospinal fluid is only occasionally diagnostic. Roentgenograms may show clouding of sinuses or erosion of their bony walls or those of the orbit. Thoracic phycomycosis is caused by inhalation of the fungi or their aspiration with material draining from ulcerative lesions in nose or mouth. It is characterized by progressive, nonspecific bronchitis and pneumonia, with superimposed signs of thrombosis and infarction, sometimes of sudden onset. Myocardial infarction secondary to invasion of coronary arteries has been observed. Abdominal-pelvic phycomycoses are thought to be caused by the ingestion of infectious material, or by hematogenous dissemination. As all regions of the gastrointestinal tract seem to be equally susceptible, the symptoms are extremely variable, and include pain, diarrhea, bloody stools, hematemesis, and signs of peritonitis. Occasionally the skin is the initial site of invasion by Phycomycetes, but the best-established cases are those reported from Indonesia, caused by Basidiobolus ranarum. There the victims have been children, in whom the

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T h e intermediate mycoses

disease began as a moveable subcutaneous nodule which gradually increased substantially in size. After several months or a few years, most cases spontaneously cleared. PATHOLOGY Aside from the pathology to be expected from the debilitating disease that accompanies phycomycosis, that caused by the fungus is usually revealed in tissue sections by large amounts of wide, irregularly branched hyphae, seldom exhibiting any septa, and easily seen with H 8c E stain. Oddly, the stains usually so helpful in other fungal diseases, such as the PAS or the Gridley method, do not serve so well in this instance as H & E. Sometimes the tubular hyphae may appear collapsed. They are from 8 to 10 microns in diameter, and sometimes even larger, in contrast with those characteristic of Aspergillus. As cellular reaction in the tissues, phycomycosis causes an acute abscess with polymorphs predominating, accompanied by much necrosis. The invasion of blood vessels by the organism permits hematogenous dissemination, and even vascular occlusion and infarction. It is easy to understand how so rapidly spreading a destructive process can be fatal even in a few days, especially when the central nervous system is involved. Phycomycosis caused by Basidiobolus ranarum is much more chronic than that caused by other fungi, and involves subcutaneous tissues in a localized area. The cellular reaction includes eosinophiles, neutrophiles, lymphocytes, and giant cells. Most of the few cases of this infection thus far reported eventually healed without specific treatment, according to Lie et al. (1956). DIFFERENTIAL

DIAGNOSIS

Phycomycosis should be suspected whenever rapidly spreading sinusitis, orbital cellulitis, bronchitis, or pneumonia develops in severely diabetic patients whose illness is far out of control, in patients with intense acidosis from any other cause, and in patients receiving intensive corticosteroid therapy with or without antibacterial antibiotics. Because the disease may easily become overwhelming in a few days, early diagnosis is imperative, and is most quickly accomplished by preparing frozen sections of tissue specimens and staining with H & E. Fortunately, cultures grow rapidly but may waste a valuable day or two, and are often difficult to differentiate from airborne contaminants. Fulminating bacterial infections must also be considered in differential. MYCOLOGY It is impossible to identify specifically the causative fungus in a case of phycomycosis by its appearance in tissue sections, beyond classifying it

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193

as a phycomycete by the characteristic wide, tubelike hyphae, sometimes collapsed, without septa and branching very irregularly so as to resemble at times the antlers of a deer. There is seldom time for sufficient cultural study to establish genus and species before the issue has been decided for the patient by death or recovery. In fact, such classification will hardly serve him well in any event, for too little is known about antifungal drugs that are more active against one species than another. Nevertheless, it is always advisable to enlist the help of an experienced mycologist specifically to identify the organism involved, so that the incidence may be statistically assessed as well as the response to antifungal therapy. Such statistics will perhaps eventually lead to better ability to match the treatment to the species actually present. T h e most commonly encountered fungi in phycomycosis belong to two genera, Rhizopus and Absidia. T h e y have structures called rhizoids, resembling complicatedly branched roots, between which hyphae called stolons extend. Long sporangiophores are borne from the stolons: in Rhizopus they are always at the level of and opposite to a rhizoid; in A bsidia they are between the rhizoids. Mucor, an occasional cause of phycomycosis, has no rhizoids, but the sporangiophores are similar to those of the other two genera. A l l three genera form sporangia at the terminal end of the sporangiophores, consisting of large globular or pear-shaped, easily ruptured structures filled with sporangiospores. These three genera produce on Sabouraud's medium rapidly growing colonies capable of filling the entire vessel within two or three days, with a loosely woven mat of hyphae. T h e rhizoids of Rhizopus and Absidia sometimes become attached to the undersurface of the lid of a petri dish, so that a part of the colony comes away attached to it when it is lifted. T h e color of the colony is usually dirty white or light brown or gray, and in many species dark-colored tiny dots, the sporangia, are scattered throughout. Further assistance in species identification, as well as a discussion of some other fungi occasionally recovered from phycomycosis, such as Mortierella and Basidiobolus, may be obtained from Medical Mycology, by Emmons, Binford, and Utz (1963), and from the Laboratory Manual for Medical Mycology, by Ajello, Georg, Kaplan, and Kaufman (1963). IMMUNOLOGY As normal human beings are highly (and probably completely) resistant to the fungi of phycomycosis, an individual's resistance must be destroyed or lowered for infection to occur. Even when no severe debilitating disease is apparent preceding the fungal invasion, nevertheless some such factor is almost certainly operative. Most cases occur in association with diabetes or other severe acidosis-producing conditions. T h a t this natural resistance is not all passive is indicated by the report of Gale and Welch, who found

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The intermediate mycoses

that normal serum can inhibit Rhizopus in vitro, whereas diabetic acidotic serum cannot. More recently, corticosteroids, in large and long-continued doses, have frequently been implicated, but it is often difficult to decide whether they alone are responsible for lowering the resistance, or whether the disease for which they are being administered is to blame. Malnutrition and vitamin deficiencies are often causative. Neoplasm or lymphoblastoma may be the inciting factor, but sometimes the modern mitosissuppressing drugs which are used to treat them seem to be at fault. Exposure to ionizing radiation, especially if extensive, may lower resistance. It is not known if any specific immunologic resistance can be acquired by man through constant exposure to such fungi as these. Skin or serologic tests have not been developed to a useful stage. T h e localized form of phycomycosis, usually caused by Basidiobolus ranarum, has healed spontaneously in most instances. Except for this type, phycomycosis is highly dangerous to life, once the infection has been established because of lowered natural resistance. THERAPY T h e most important factor in the treatment of phycomycosis is the early recognition that some other severely debilitating disease is also present. T h e fungal disease must be diagnosed accurately and early, and vigorously combated by every helpful means if success is to be achieved. W i t h severe diabetics there is often an intensive race against time. T h u s far only sporadic success has been reported with antifungal drugs. Emmons (Emmons et al., 1961) recommends trial with antibiotic X-5079C (Hoffman L a Roche), based on experiments in vitro and in animals. Most strains of these fungi are inhibited by amphotericin B in vitro at levels below 0.06 mg per ml, and the drug can protect animals against lethal inoculations. It is, however, only fungistatic, and administration must be continued to prevent recurrence of the disease. Although clinical trials have not been numerous, amphotericin B is credited with saving life in several cases. Nystatin is effectively inhibitory in vitro, but its toxicity makes its parenteral use dubious. Some species of Phycomycetes are inhibited in vitro by griseofulvin, but thus far little clinical success has been reported. Cycloheximide seemed to help the patient in the case reported by Landau and Newcomer (1962). Potassium iodide in large dosage was formerly the only creditable drug, and it may still deserve to be added to the regimen, although its contribution will probably not be great. Anticoagulants should be considered because of the high incidence of thrombosis associated with phycomycosis. Autogenously prepared vaccines perhaps warrant similar consideration. Surgical drainage or actual excision of involved tissue is often needed in phycomycosis, and the outlook has been improved by combining such surgery with the use of antifungal drugs.

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Bibliography Baker, R . D. 1956. Pulmonary mucormycosis. Amer. J. Pathol., 32:287-313. . i960. Diabetes and mucormycosis. Diabetes, 9:143. Baker, R. D., D. E. Bassert, and E. Ferrington. 1957. Mucormycosis of the digestive tract. Arch. Pathol., 6:176. Baker, R . D., D. H. Seabury, and J. D. Schneidau. 1962. Subcutaneous and cutaneous mucormycosis and subcutaneous phycomycosis. Lab. Invest., 11:1091. Bauer, H., G. L. Wallace, Jr., and W. H. Sheldon. 1956. T h e effects of cortisone and chemical inflammation on Rhizopus oryzae infection. Amer. J. Pathol., 32:627. Berk, M., G. I. Fink, and C. T . Uyeda. 1961. Rhinomucormycosis: report of a case diagnosed by clinical signs. J. Amer. Med. Assoc., 177:511. Burrow, G. N., R. B. Salmon, and J. P. Nolan. 1963. Successful treatment of cerebral mucormycosis with amphotericin B. J. Amer. Med. Assoc., 183:370. Chick, E. W., J. Evans, and R. D. Baker. 1958a. Treatment of experimental mucormycosis (Rhizopus oryzae infection) in rabbits with amphotericin B. Antibiotics and Chemotherapy, 8:394. . 19586. T h e inhibitory effect of amphotericin B on localized Rhizopus oryzae infection (mucormycosis) utilizing the pneumoderma pouch of the rat. Antibiotics and Chemotherapy, 8:506. Dwyer, G. K., and G. W . Changus. 1958. Rhino-mucormycosis resulting in fatal cerebral mucormycosis. Arch. Otolaryngol., 67:619. Emmons, C. W., G. W . Lones, and W. R. Piggott. 1961. Chemotherapeutic activity, toxicity, and serum assay of a new antimycotic antibiotic, X-5079C. [Abstract.] Amer. Rev. Respir. Diseases, 84:115. Feinberg, R., and T . S. Risley. 1959. Mucormycotic infection of arteriosclerotic thrombus of the abdominal aorta: report of a case. New Engl. J. Med., 260:626. Gass, J. D. M. 1961. Ocular manifestations of acute mucormycosis. Arch. Ophthalmol., 65:226. Grunberg, E., J. Berger, and E. Titsworth. 1961. Chemotherapeutic studies on a new antifungal agent, X-5079C, effective against systemic mycoses. [Abstract.] Amer. Rev. Respir. Diseases, 84:504. Hutter, R . V. P. 1959. Phycomycetous infection in cancer patients. Cancer, 12:330. Hyun, B. H., and F. C. Collier, i960. Mycotic endocarditis following intracardiac operations: report of four cases. New Engl. J. Med., 263:1339. Landau, J. W., and V. D. Newcomer. 1962. Acute cerebral phycomycosis (mucormycosis). J. Pediatr., 61:363. Lie, K. J., and N. I. T . Eng. i960. Subcutaneous phycomycosis: a new disease found in Indonesia. Ann. N.Y. Acad. Sci., 89:4. Lie, K. J., N. I. T . Eng, A . Pohan, H. van der Meulen, and C. W . Emmons. 1956. Basidiobolus ranarum as a cause of subcutaneous mycosis in Indonesia. Arch. Dermatol., 74:378-383. McBride, R . A., J. M. Corson, and G. J. Dammin. i960. Mucormycosis: two cases of disseminated disease with cultural identification of Rhizopus. Amer. J. Med., 28:832.

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Merriam, J . C., and C. G. Tedeschi. 1957. Cerebral mucormycosis: a fatal fungus infection complicating other diseases. Neurology, 7:510. Montenegro, M. R., T . de Brito, J . Lombardi, and C. da S. Lacaz. 1959. Mucormicose intestinal: registro de dois casos. Rev. Hosp. Clin. Fac. Med. (Sao Paulo), 14:59. [English summary, Rev. Med. Vet. Mycol., 3(i959)'-225-] Paltauf, A. 1885. Mycosis mucorina: ein Beitrag zur Kenntniss der menschlichen Fadenpilzerkrankungen. Virchows Arch. Pathol. Anat., 102:543. Rabin, E. R., G. D. Lundberg, and E. T . Mitchell. 1961. Mucormycosis in severely burned patients. New Engl. J . Med., 264:1286. Utz, J . P., V. T . Andriole, and S. M. Sapesin. 1961. Chemotherapeutic activity of X-5079C in systemic mycoses in man. [Abstract.] Amer. Rev. Respir. Diseases, 84:115. Wade, J . L., and A. R. K. Matthews. 1940. Cutaneous mucor infection of face. J . Amer. Med. Assoc., 114:410. Watson, K. C., and P. B. Neame. i960. In vitro activity of amphotericin B. on strains of mucoraceae pathogenic to man. J . Lab. Clin. Med., 56:251. Zimmerman, L. E. 1955. Fatal fungus infections complicating other diseases. Amer. J . Clin. Pathol., 25:46.

i6 Aspergillosis

INTRODUCTION SEVERAL SPECIES of fungi belonging to the large group included in the genus Aspergillus have occasionally been observed to cause disease in man. As in phycomycosis, many times this diagnosis has been made only by examining histologic sections of material obtained at autopsy, when no material is left untreated with formalin to yield cultures by which the species of fungus could be identified. W h e n identification has been possible, however, one species, A. fumigatus, has been found to predominate.

Although subject to considerable variation, two clinical types predominate in human infections: (1) the formation of a large ball of the causative fungus within the tissues of the lung; or (2) a severely invasive fungal infection superimposed upon another seriously debilitating disease. HISTORY Virchow reported a case of aspergillosis in 1856. In 1897 Renon described six cases, some of them associated with tuberculosis. A n increase in inci197

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The intermediate mycoses

dence in recent years has been attributed to the lowering of natural resistance because of the administration of corticosteroids and antineoplastic drugs. ETIOLOGY It is not accurate to attribute aspergillosis to fungi alone, because they are probably entirely nonpathogenic for normal persons. Even the species reputedly most responsible for causing human infections, A. fumigatus, and conclusively known to be highly and primarily pathogenic for birds, especially newly hatched fowls, is undoubtedly contacted regularly by most normal persons without any resulting disease. T h e true etiology is some other factor that lowers the natural resistance of the tissues, either locally or systemically, enough to allow the fungus an opportunity to add its noxious effects. Consequently these organisms must be classed strictly as opportunists where human disease is concerned. Formerly the principal cause was a debilitating disease like neoplasm, lymphoblastoma, tuberculosis, or a systemic mycosis, and of course the incidence due to these illnesses continues. In contrast with phycomycosis (mucormycosis), diabetes does not appear prominently as a cause of aspergillosis. Injuries to certain tissues, such as the cornea, and sometimes to the skin may lower tissue resistance sufficiently. Some pulmonary infections, particularly those that develop large fungus balls, are attributable to pneumoconiosis or silicosis. A significant increase in the incidence of aspergillosis in recent years has definitely been associated with the growing dependence on intensive and prolonged corticosteroid hormone therapy for different types of systemic disease (Zimmerman, 1950; Torack, 1957), although in many instances it is impossible to avoid the conclusion that the debilitating effect of the disease undergoing such treatment may itself be equally responsible for conferring pathogenic powers upon the fungus. Similarly, intensive antibiotic and antineoplastic drug therapy has recently become a prominent cause of aspergillosis. T h e effectiveness of both these factors has been confirmed by animal experiments (Sidransky and Friedman,

1959)Aspergillus spores are almost ubiquitous, and they easily colonize saprophytically many types of localized disease, especially those producing exudates, which are very efficient culture media during their deterioration. T h u s they are often found in ear canals, either in the cerumen in normal ears or in discharges coming from internal ear disease or from otitis externa. They are also commonly superimposed on onycholysis and onychomycosis caused by dermatophytes or Candida. Here their contribution to the cause of disease approaches zero.

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It is possible that massive inhalation of Aspergillus spores (particularly of those of A. fumigatus) may result in disease without any antecedent pathology. Under certain conditions this fungus grows luxuriantly on decaying vegetation, compost, cereal grains, cotton, wool, or hay, and workers with these materials may find it an industrial hazard. Most cases of this type are of an acute pulmonary disorder called farmer's lung, more allergic than infective. Some cases of granulomatous disease seem to have been similarly caused, but it is likely that the incidence would be higher than it is if this source of infection was very effective alone. It is therefore wise always to search diligently for other disease. Aspergillus is a large genus of fungi, and many of its species are widely distributed throughout the world. A t least seven species have been shown to be agents of disease in man under the proper circumstances. T h e vast majority of infections are caused by A. fumigatus. T h e fungi usually enter the body by inhalation, but some cases have resulted from inoculation through the epithelium or into wounds. T h e r e is no evidence that aspergillosis is transmitted from man to man or from animals to man.

CLINICAL

CHARACTERISTICS

Pulmonary aspergilloma T h i s manifestation of the disease is characterized by round, oval, or flattened masses, firm and heavy, composed largely of fungus, matted together with inhaled dust of sand or coal, decomposing exudate, and host cells. These masses may become surprisingly large, sometimes 10 centimeters or more in diameter. T h e y begin either in an ectatic bronchus or in a cavity caused by other disease such as tuberculosis or histoplasmosis, and slowly enlarge. Often they interfere very little with general health. Riddell (1956) and Schwarz and Baum (1961) have covered this subject well. Pulmonary granulomatous aspergillosis T h i s infection is much more virulent than the preceding one. Most commonly caused by A. fumigatus, it is usually seen near the end of an extremely debilitating disease, especially when the patient is being treated with antibiotics and corticosteroids. T h e infection begins in the bronchi and penetrates into the parenchyma of the lung, rapidly causing necrosis and cavitation. Fever and cough, producing blood-tinged purulent spu-

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Fig. 11. Aspergillosis. Bilateral chronic pulmonary disease with fungus ball (aspergilloma) which almost fills large cavity in left upper lobe. tum, and sometimes hemoptysis are characteristic. T h e r e is considerable toxicity, particularly when the disease is caused by A. fumigatus. Sometimes dissemination of the fungus occurs hematogenously to other parts of the body, notably brain, myocardium, kidneys, skin, and bone. T h e cornea or the orbit may be invaded by Aspergillus through direct implantation in individuals whose resistance is extremely low, particularly diabetics, when the syndrome discussed under phycomycosis (see chap. 15) is duplicated.

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Fig. 12. Aspergillosis. Osteomyelitis of ulna with sclerosis and periosteal bone formation, and a fracture.

considerable pathological

PATHOLOGY Often the pulmonary aspergillomas (fungus balls) do not stimulate much tissue reaction nearby. In sections from pneumonectomy or lobectomy specimens or in autopsy material from the granulomatous pulmonary form the fungi are easily seen in nodular masses or diffusely in the parenchyma, usually in heavy concentrations. T h e hypae often invade the blood vessels, causing thrombosis and obstruction and furnishing fragments for hematogenous dissemination. Necrosis is extensive, especially when the causative organism is A. fumigatus, and the reaction is acute and pyogenic. All these changes are superimposed upon those of some other pathologic process, which almost invariably was present before the fungal invasion. T h e fungus hyphae seldom take the routine H 8c E stain well, and it is advisable to use the PAS or the Gridley method. Sporulation does not

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usually occur in the tissues, but the appearance of rounded spores may be simulated by hyphae that are cut at right angles in the sectioning. T h e hyphae are up to 4 microns in diameter, and cross walls may be discovered; thus they are noticeably different from the larger ones of phycomycosis, which lack septa. Sometimes there are localized accumulations of radiating hyphae, vaguely resembling the granules of actinomycosis, but the large hyphal size makes differentiation easy. Sporulation occasionally occurs in cavities, and the typical vesicle with chains of rounded spores growing peripherally from it, typical of Aspergillus, may be found. A few cases have shown considerable attempt at body resistance by the formation of dense fibrosis. DIFFERENTIAL

DIAGNOSIS

Aspergillosis may be easily diagnosed in patients debilitated by any of the previously named diseases who are producing purulent sputum, because typical fragments of the fungus may be found in such material, particularly after its digestion with sodium hydroxide. T h e appearance of the fungi in tissue sections has been described above. Cultures are of assistance, but must be carefully evaluated because Aspergilli are frequently encountered in routine cultures purely as contaminants. (Fortunately the most active pathogen, A. fumigatus, is not commonly found as such.) MYCOLOGY Species identification among the members of the genus Aspergillus is difficult and requires the services of a good mycologist. Identification should be undertaken whenever possible in order to further our understanding of statistical incidence and epidemiology, although it is seldom of assistance in treating the patient at hand. T h u s far there is little indication that an antifungal drug can be selected on the basis of the species of fungus involved. Unfortunately, in many cases the diagnosis is made during microscopic examination of autopsy material, when no unpreserved specimens are available to yield cultures. T h e r e is some discussion of Aspergilli in general in Part IV of this volume, dealing with medical mycology; here only the predominant organism for aspergillosis is considered. Aspergillus fumigatus Fresenius 1950 produces a rapidly growing colony, white at first, but soon becoming grayish-green because of the formation of fructifying aerial forms. Microscopic examination shows smooth conidiophores enlarging into a vesicle at the distal end. T h e upper globular surface is covered with short stems, each bearing a chain of rounded or spherical spores, each spore being from 2 to 4 microns in diameter.

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Several species of animals can be infected experimentally, and A. fumigatus is highly pathogenic for birds. Animal inoculations are not useful in differential diagnosis. IMMUNOLOGY Beyond the fact that normal persons are almost invariably immune to actual infection by species of Aspergillus, little is known about immunology. Attempts to devise testing procedures using antigens extracted from these fungi have not progressed far enough to be of service in diagnosis or prognosis. THERAPY Surgical removal is the only treatment for localized aspergillomas, the so-called fungus balls; it is too much to expect the absorption of such masses, even if all the involved fungi could be killed. Infections reasonably localized to one lobe or one lung may similarly be extirpated. T h e morbidity of such procedures is notably reduced by the concomitant administration of antifungal drugs. In other forms of aspergillosis, the first concern is to seek, diagnose accurately, and treat intensively the underlying pathologic process which, almost invariably present, is responsible for conferring pathogenicity on these usually harmless fungi. Occasionally this procedure is not helpful, for the infection may have been caused by the treatment for the underlying disorder; the best example is corticosteroid therapy for collagen disease. Amphotericin B is not very effective in vitro against Aspergilli, but it appears to have been helpful in an encouraging number of human infections, and continued trials are advocated by Procknow (196a). Paradoxically, griseofulvin, which does exhibit fungistatic powers in vitro, has not lived up to expectations in clinical usage. Nystatin, although an efficient antagonist for Aspergilli, is difficult to administer systemically. In concentrations ranging from 100 to 500 units per ml in aqueous suspension, instilled into the pleural space or the space remaining after pneumonectomy or inhaled in an aerosol spray, nystatin has seemed helpful in several instances. Potassium iodide in massive dosage (up to 30 gm daily) has been effective in a few cases (more impressively against A. niger than against A. fumigatus). Bibliography Hazen, E. L., and R. Brown, i960. Nystatin. Ann. N.Y. Acad. Sci., 89:1. Ikemoto, H. 1964. Pulmonary aspergilloma or intra-cavitary fungus ball: report of 5 cases. Sabouraudia, 3:167.

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Peer, E. T . i960. Case of aspergillosis treated with amphotericin B. Diseases of the Chest, 38:222. Pinto, E., S. Gandra, R. Gonzaga, V. de Macedo, and P. de Aguiar. i960. Aspergillosis developed in preformed cavities in the lung: 4 cases treated with exeresis. Portugal Med. (Porto), 44:227. Procknow, J . J., and D. F. Loewen. i960. Pulmonary aspergillosis with cavitation secondary to histoplasmosis. Amer. Rev. Respir. Diseases, 82:101. Toigo, A. i960. Pulmonary aspergillosis: variable pulmonary picture, simulating lobar pneumonia, bronchopneumonia, lung abscess, intra-bronchial mycetoma, bronchiectasis, tuberculosis or carcinoma. Amer. Rev. Respir. Diseases, 81:392. Weller, E. A., D. J . Josephs, and J . F. Hora. i960. Deep mycotic involvement of the right maxillary and ethmoid sinuses, the orbit and adjacent structures: case report evaluating the use of nystatin locally and amphotericin B intravenously against Aspergillus flavus. Laryngoscope, 70:999.

!7 Rhinosporidiosis

INTRODUCTION organism named Rhinosporidium seeberi, usually accepted as a fungus, occasionally causes a human disease. T h e disease is characterized by chronic granulomatosis in the form of polypoid masses primarily involving mucous membranes. T h e nose is most frequently invaded.

A MICROBIAL

HISTORY Malbran discovered the first case of rhinosporidiosis in Argentina in 1892, when he examined a polyp from the nose. T h e organism was described by Seeber in 1896, and named by Wernicke in 1900. Subsequently many studies were reported from India, where the infection is most prevalent, beginning with those of O'Kinealy in 1903 and of Minchin and Fantham in 1905. Karunaratne (1936) reported a series of 104 cases. In 1949 de Mello was able to estimate that a total of 443 cases had thus far been reported. 205

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The intermediate mycoses ETIOLOGY

T h e organism causing rhinosporidiosis has never been discovered in nature and has never been successfully cultured, either on artificial media or by animal inoculations. Its status depends entirely on the interpretation of its appearance in tissue under the microscope. DISTRIBUTION Rhinosporidiosis occurs sporadically in many parts of the world, but more than half of the recorded cases have been discovered in India, and another fourth, in Ceylon. From South America (principally Argentina, Brazil, and Paraguay) more than thirty cases have been reported, whereas Africa and North America have each contributed a smaller group. Males are affected ten times as often as females, and usually between the ages of ten and forty. There is no apparent difference in susceptibility because of race or color of skin. There is a relationship with certain activities connected with rivers, such as diving against or handling sand from the riverbed. EPIDEMIOLOGY As the natural habitat of the causative organism has not been discovered, little can be said about the epidemiology of rhinosporidiosis. There are no examples of direct transmission from person to person. Animals do become infected occasionally by natural means, but there is no known instance of transmission from them to man. Noronha and Mandlik believe that rhinosporidiosis is usually acquired by persons diving into rivers and striking their faces on the sand at the bottom. They attribute the rarity of the infection in women to the social inhibitions in India, which permit females little freedom to bathe in rivers. It has been suggested that aquatic animals, such as fish or frogs, may harbor the organisms. CLINICAL

CHARACTERISTICS

Rhinosporidiosis, appearing first in the nasal apertures in more than 90 percent of the cases, presents itself as polypoid masses, either sessile or pedunculated, of highly vascular friable tissue, often sufficient to obstruct the air passages. Similar lesions occur commonly in the nasopharynx and on the soft palate. T h e mucus which is profusely discharged is sometimes purulent and bloody. T h e surface of the polyps may resemble that of a cauliflower, and such lesions may grow to a large size. T h e surface shows

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numerous small white spots which are actually the mature sporangia of the organism. W h e n the eye is involved, as it often is, the resulting pain, lacrimation, and photophobia are sufficient to cause the patient to seek medical attention earlier than when other areas are affected. It is believed that many such cases are successfully treated by removal of the offending masses while they are still too small to be diagnosed as rhinosporidiosis, and are thus lost to statistics. T h e lachrymal sac may be invaded, causing a soft fluctuant swelling near the inner canthus and granulomatous verruca, or even neoplasm. Less frequently, similar lesions may develop in lips, larynx, vulva, vagina, urethra, or penis, and in fact in any mucous membrane. It is accepted that many of these lesions occur by transplantation of the organisms with the fingernails, but lymphatic or even hematogenous spread is considered likely. Skin lesions, recorded in only about five cases, are described as originating as subcutaneous nodules which enlarge to form papillomatous verrucous tumors. PATHOLOGY Grossly the specimen may appear as an ordinary polyp, but the extreme friability of the tissue and the presence of tiny white spots should alert the experienced pathologist. T h e r e can be little doubt, however, when tissue sections are examined. T h e sporangia of R. seeberi are so large and numerous that they cannot be missed, and nothing else duplicates their appearance. T h e y vary from 10 to 300 microns in diameter, are thickwalled when small and thin-walled when large, and contain numerous endospores which are lobulated on their surfaces and stain deeply with H & E. Some of the sporangia which have ruptured and extruded their contents into the surrounding tissue appear as semilunar cavities with a thin wall. Special fungus stains are not necessary, but the organisms take the PAS and Gridley stains well. T h i s infection calls forth a subacute to chronic granulomatous infiltrate composed of neutrophiles, lymphocytes, and plasma cells. T h e multiplicity of new capillaries is striking. There may be papillomatous hyperplasia of the surface epithelium if it has not disappeared completely; it will be of the stratified squamous variety of the columnar type with few or many mucous glands, depending on the region involved. DIFFERENTIAL

DIAGNOSIS

Clinically, rhinosporidiosis must be differentiated from many other disorders in the early stages, but when well developed it presents a characteristic picture. T h e friable, pedunculated polyps with tiny white spots are

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typical. Syphilis, tuberculosis, leprosy, leishmaniasis, yaws, rhinoscleroma must be ruled out. In contrast, coccidioidomycosis almost never involves mucous membranes, and its lesions do not become polypoid. Microscopically, only coccidioidomycosis can be confused with rhinosporidiosis. It it differentiated from the latter by its smaller spherules with round nonlobulated endospores, only the periphery of which tends to take much stain. MYCOLOGY Rhinosporidium seeberi (Wernicke 1912) has never been grown in culture or in experimentally inoculated animals. Ashworth (1923) and later Karunaratne (1936), after studying the organism extensively in tissue sections, concluded that it is a phycomycete belonging to the order of Chytridiales. A spore may be as small as 6 microns when extruded from the mother cell, and is rounded or oval with a lobulated surface. It increases to about 12 microns, and has a wall that appears to be doubly contoured, a nucleus, and cytoplasm. T h e nucleus begins to divide at this point, and as the cell grows as many as 16,000 endospores may form by the time it reaches its maximum size of 300 microns, when it is just visible to the naked eye. One spot in the wall becomes thinner, and eventually opens into a pore through which the endospores are extruded. Although Ashworth (1923) apparently established this organism as a fungus, its failure to yield to cultures is a handicap to further clarification. Both Rettie and R a o have reported successful cultures, but their work has never been confirmed. Attempts have been made, but without success, to reproduce the disease in dogs, guinea pigs, and monkeys. T h i s failure is difficult to explain, because animals such as dogs, horses, mules, and cows do become infected by natural means. Perhaps a local or systemic disease must be present to lower the animal's normal resistance before infection can occur. IMMUNOLOGY Except for the implication suggested in the preceding paragraph, leading to conjecture about human rhinosporidiosis, nothing is known about the immunology of this disease. THERAPY Many medicaments have been tried in the treatment of rhinosporidiosis without success. Trivalent antimony compounds in ointment form are inefficient, although some success has been reported with an aqueous solution of 2 to 5 percent of antimony potassium tartrate (tartar emetic).

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and by the injection of ethylstibamine (neostibosan) up to a total dosage of 2 to 4 grains (Allen and Dave, 1936). Surgical removal is usually necessary, preferably followed by electrocoagulation of the base to prevent the reimplantation of the organisms on the cut surfaces. Recurrence is common even after efforts to achieve complete removal.

Bibliography Agrawal, S., K. D. Sharma, and J. B. Shrivastava. 1959. Generalized rhinosporidiosis with visceral involvement: report of a case. Arch. Dermatol., 80:22-26. Allen, F. R . W . K., and M. Dave. 1936. Treatment of rhinosporidiosis in man, based on 60 cases. Ind. Med. Gaz., 71:376. Ashworth, J. H. 1923. O n Rhinosporidium seeberi (Wernicke, 1903) with special reference to its sporulation and affinities. Trans. Roy. Soc. Edinburgh, 53:301342Azevedo, M. L. de, A . Belletato, and A . Krug. 1961. Conjunctival rhinosporidiosis: fourth case from Brazil. [In Portuguese.] Argentin. Brasil. Oftalmol., 24:37. Caldwell, G. T . , and J. D. Roberts. 1938. Rhinosporidiosis in the United States. J. Amer. Med. Assoc., 110:1641. Karunaratne, W . A. E. 1936. Pathology of rhinosporidiosis. J. Pathol. Bacteriol., 42:i93Meniola, R., and R . Cortés Ochoa. 1950. Rhinospohidiosis: primer caso en Mexico. Rev. Inst. Salubr. Enferm. Trop., 11:1. Purandare, N. M., and S. M . Deoras. 1954. Rhinosporidiosis in Bombay: 100 cases. Ind. J. Med. Sci., 7:603. R a j a m , R . V., G. S. Viswanathan, A . R . Rao, P. N. Rangiah, and V. C. Anguli. 1955. Rhinosporidiosis: a study with report of a fatal case of systemic dissemination. Ind. J. Surg., 17:1-30. Tirumurty, T . S. 1914. Rhinosporidium kinealyi. Practitioner, 93:704.

i8 Dermatophytosis

INTRODUCTION of fungi capable of causing human disease reveal a distinct preference to limit their pathogenic activities to the skin and its appendages, and are therefore called dermatophytes. Only under very exceptional circumstances do they survive or proliferate in the deeper tissues of the body. In fact, they do not even invade the dermis except when fortified by rarely encountered factors, and usually prefer an even closer restriction to the keratinized parts (and the prekeratinizing cells) of epidermis, hair, and nails. They might more appropriately have been named "epidermatophytes" or "keratinophytes." T h e diseases that result show considerable clinical variation, due more to variations in the anatomy of the affected regions of the human body than to specific variations in the activities of the fungi, although in several instances the latter are also important. Even today, clinicians who deal with these diseases find it worthwhile to utilize a classification based mostly on clinicoanatomic characteristics, giving appropriate consideraA GROUP

213

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tion to variations caused by particular fungi. (This subject is treated in more detail in the section on clinical characteristics.) HISTORY As early as 1841 David Gruby conclusively proved for the first time, by studying a fungous infection of the skin called favus, that a microbial organism could cause human disease. Culturing the fungus from infected lesions, he reproduced the disease by reinoculating the fungus into normal areas of skin, thereby fulfilling what became famous forty years later as Koch's postulates in relationship to tuberculosis, which are still acceptable as the criteria needed to establish a microbe as the cause of a disease. T h u s mycology is truly the oldest of the medical microbial sciences. Indeed, in 1837 Remak had noted the presence of filaments resembling a mold in material taken from favus, and two years later Schoenlein showed that these elements were of fungal origin, and therefore belonged to the plant kingdom. Gruby, however, was the true pioneer, even volunteering his own skin for experimental inoculations (as Remak did, too). Gruby also discovered the fungus of thrush, now known as Candida albicans, and other dermatophytes, such as those in the genus Microsporum and the endothrix type of Trichophyton. But his observations did not receive the credit they deserved, and confusion reigned for half a century. In 1892 Sabouraud began to issue voluminous reports on fungous diseases of the skin, culminating in a monumental contribution in 1910 in a single large volume, Les Teignes [The Tineas] devoted entirely to this subject. It is still worthy of being called the bible of dermatologic mycology. Sabouraud realized the complex manner in which these fungi grow in culture, with successive cultures taken from the same parent stock often exhibiting wide variations. T h i s capacity for variation, known as pleomorphism, has rendered classification of these organisms extremely difficult; although Sabouraud did his best, he described as separate species several fungi now believed to be simply variants within a single species. In succeeding years too much attention was paid to minutiae by persons not well enough oriented to realize the triviality of many of their observations; real progress was also impeded by incomplete and inaccurate study and careless reporting. As a result of these misguided endeavors, several hundred "new species" of fungi were described and named as pathogens of the human skin. T h i s complexity, by preventing successful classification of human diseases based on species of fungi, forced clinicians to adopt the clinicoanatomic or "topographical" categorization mentioned above. T h e "splitters"—mycologists who create a new species for every small variation exhibited by fungi in culture—were having their heyday. Beginning in the 1920's, when Hopkins and Benham organized a lab-

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oratory oriented toward dermatologic mycology at Columbia University, and continued by several outstanding students of mycology who took some training there, an almost complete reversal of the splitting tendency has taken place. In 1934 Emmons outlined in extensive detail a strict botanical classification which listed all the dermatophytes under three genera, embracing a total of only about sixteen species. His classification, which did not significantly conflict with the clinical characteristics of the resulting diseases, was enthusiastically accepted by clinical dermatologists and laboratory technicians, who began to utilize and study the cultural aspects of medical mycology, now reduced to practical limitations by the elimination of almost all the earlier confusion. Moreover, most of the expert mycologists in the United States, South America, and England also followed Emmons' lead. Conant reduced 172 synonyms for the causative organism of moniliasis to one species of Candida albicans. Georg and Plunkett, working independently, demonstrated that four of Emmons' "species" of Trichophyton could logically be reduced to simple variants of one species, T. tonsurans, reducing the number of his valid species of Trichophyton from twelve to nine. This simplified classification, acceptable to clinicians and mycologists alike, provided the strongest possible impetus toward widening the base of dermatologic mycology. Dermatologists in ever-increasing numbers began to employ culture methods in their clinics and private offices, and performed a large percentage of the identifications themselves. Instead of depriving expert mycologists of their rightful field by engaging in laboratory activities, clinicians rather frequently uncovered odd varieties of fungi on which they sought expert help; the mycologists were thereby afforded many interesting opportunities for investigation at their own level which might have been lost had no specimens been placed on culture out on the "firing line." As a result, highly trained and competent mycologists were appointed to work in well-equipped laboratories in most university medical centers in interested countries. This trend is continuing, and is steadily raising the standards of practice not only in large cities, but also in smaller communities and hospitals. At present, the vast majority of patients with fungous disease are examined by dermatologists who receive mycologic laboratory assistance in diagnosis wherever indicated. It has become increasingly evident that no clinician can efficiently differentiate by visual means alone between fungous infections of skin, hair, and nails and those of nonfungal origin. ETIOLOGY The fungi that cause disease in human skin, hair, and nails are probably contacted by almost all persons at some time or times during their lives, yet actual infection is comparatively rare. Many known factors, and undoubtedly some as yet unknown, are of great etiologic importance. As

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some of these factors are immunologic in nature, this subject is treated generally in the section on immunology, or in connection with specific clinical syndromes. DISTRIBUTION T h e r e is no geographic area in the world where human beings are never infected by dermatophytes, but wide variation exists in the incidence of different types. Local climatic conditions affecting nutrition, hygiene, and clothing habits, such as those promoting excessive perspiration in some areas of the body, may lower resistance. Also, certain fungi, like many other types of plant life, prefer to live and proliferate in certain geographic localities, often for reasons not clearly understood. T h u s definite geographic concentrations of cases are caused by certain species of fungi. No dermatophyte infections are completely limited by age or sex, but certain species prefer certain ages. These factors are discussed in connection with specific clinical syndromes whenever they are important. In general, neither race nor skin color seems to be an important factor. EPIDEMIOLOGY Some species of dermatophytes grow almost exclusively on human beings; some prefer animals, but cause human infections if given the opportunity; some are normal inhabitants of the soil. T h e first type, being transmitted easily from person to person, may cause veritable epidemics. T h e second type is usually acquired directly through contact with animals, but is occasionally transferred directly from human to human. T h e third type is capable of all three modes of transference, but acquisition directly from the soil predominates. CLINICAL

CHARACTERISTICS

With only a few limitations, any dermatophyte may clinically infect skin, hair, or nails, but it is surprising how large is the concentration of certain species in one clinical type. T h i s fact makes it reasonable to discuss these diseases in the manner followed here, using the clinician's topographical classification and including in each category the principal features of the particular species of fungus most frequently encountered, even though that species may not be the exclusive cause of the particular disease. (For further information see the more detailed descriptions of these fungi in Part IV, dealing with the fundamentals of medical mycology.) Tinea capitis (ringworm of the scalp) Ringworm of the scalp exists in several different clinical forms, each caused rather consistently, although not invariably, by its own species

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of dermatophyte. Although none of these is strictly limited geographically, there are tremendous percentage variations in their distribution over the globe. The vast majority of cases occur in prepubertal children, concentrated in those between the ages of three and eleven, and predominating in males. Within this group there are two types, roughly differentiated as noninflammatory and inflammatory. Except for odd percentage distributions encountered in certain geographic areas, and for chronologic variations owing to epidemic manifestations, these two may be called the common forms of tinea capitis. Noninflammatory, human, or epidemic type.—Also called gray-patch ringworm, this form of tinea capitis is usually caused by Microsporum audouinii, and is always acquired by direct transmission from child to child or indirectly through inanimate objects, such as caps or theater seats. Animals seldom become infected with this organism. The infection has often reached epidemic proportions, lasting for years in some localities. The disease begins as a simple scaling in one or more areas of the scalp, most commonly in nape or occiput, which spreads from the point of inoculation peripherally to form round or oval patches, and eventually polycyclic areas by coalescence. Soon the hairs in the central parts of these areas become lusterless, and so brittle that they break off close to the point of emergence from the follicles. They show little tendency, however, to become loosened in the follicles, and so are not ordinarily shed completely. As there is usually little itching, the patient may fail to notice the ailment until it has become extensive. This form of tinea capitis is resistant to treatment, but when affected areas finally do heal, there is no permanent hair loss or scarring. Microsporum audouinii Gruby 1843 grows slowly in culture producing a light-brown colony, with only a thin fuzz of aerial mycelium. On the reverse of the culture it produces a color varying from yellowish-tan to coral, or pink in the thicker parts. On Sabouraud's glucose agar it sporulates poorly; only rarely are macroconidia found, and even then they are usually irregularly formed and abortive. A few microconidia may usually be discovered along the sides of the hyphae to help in ruling out a nonpathogenic contaminant. If it is known that the inoculation consisted only of typically fluorescent hairs extracted singly under dark light (to be discussed later) from well-cleansed surfaces, the chance of confusion with nonpathogenic fungi is reduced. Inflammatory or animal type.—This form of tinea capitis is characteristically caused by Microsporum canis (lanosum and felinum are synonymous). The infection is almost invariably acquired by a child through direct contact with an infected pet animal, most commonly a cat or a dog. As direct transmission from child to child seldom occurs, true epidemics do not appear. Occasionally, similar cases are caused by Micro-

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sporum gypseum (fulvum), which is apparently contracted directly from the soil where this organism grows saprophytically. The initial lesion is probably a scaly condition of the scalp, but the disease is seldom noticed in this early stage. An erythematous papular area is usually seen first, with hairs in the centers of the papules. Soon a patch is formed, within which the hairs lose their luster, become brittle, and are broken off close to the base. Later the inflammation so loosens some hairs that they fall out. Itching is usually present, and may be severe. There may be only a single patch of the infection, but more often extensive involvement eventually occurs. All degrees of inflammation may accompany the disease process, but in each case all lesions tend to be in the same stage at a particular time. At first the inflammation is mild, and may increase gradually for a time, but in many cases it very suddenly becomes severe. At its worst it is accompanied by pronounced swelling, developing into deep, boggy ulcerative areas exuding pus, known as kerion Celsi. Severe constitutional reactions may characterize this stage. Considerable scarring and permanent hair loss are to be expected after such areas heal. Microsporum canis Bodin 1902 grows more rapidly in culture than M. audouinii, and produces a colony much more richly covered with mycelial fuzz, at first white, but soon showing a characteristic yellow coloration, really not in the filaments themselves, but produced beneath and extending into the agar. On the reverse the young colony shows a bright lemon-yellow coloration, becoming darker and more orange as it grows older. Usually abundant macroconidia are seen microscopically; they average 15 by 80 microns in size, are thick-walled and usually bluntpointed at the terminal end, and have seven to twelve cross walls and a surface usually covered with rather thick spines. A specialized cell connects this spore to the bearing hypha which degenerates to allow it to become free easily. Small pear-shaped microconidia are also frequent, borne along the hyphae on short necks and averaging 3 to 4 microns in size. Microsporum gypseum (Bodin) Guiart and Grigorakis 1928 grows much more rapidly than the preceding Microsporum species, and produces abundant aerial mycelium, soon becoming covered with a light-brown or buff-colored powder. Little definitive color is to be seen on the reverse, although there is sometimes a light yellow-brown shade. Under the microscope one can see that the brown powder is composed of myriads of macroconidia, somewhat shorter, wider, and thinner-walled than those of M. canis, with fewer cross walls, less pointed at the terminal end, and covered with very fine hairlike spines, or sometimes smooth. The breakaway cell is never so prominent as in M. canis. Microconidia are also present, but in much smaller numbers than the macroconidia; they are similar to those described for M. canis.

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The recent discovery that Microsporum gypseum can be recovered in culture from the soil in many areas of the world by "baiting" the culture plates with sterilized hair has led to numerous studies, not only of this organism, but of several closely allied fungi now being classified as different species. On such hair-baited cultures the perfect forms of several of these fungi have been conclusively demonstrated, thus removing them from the group of Fungi Imperfecti where they have so long resided. As some of these fungi never cause human disease, and some only rarely, such differentiation is of comparatively little importance to the clinician. Whenever possible, however, specimens of M. gypseum recovered in culture should be turned over to expert mycologists so that these investigations can be continued, eventually to clarify their clinical incidence and help in our understanding of their epidemiology. (Further details of the interesting mycology of this group of organisms may be found in the chapters on the fundamentals of mycology.) In both the noninflammatory and the inflammatory types of tinea capitis, the diagnosis must be confirmed by microscopic examination of an extracted hair root prepared with KOH solution. A mantle of round to oval spores, each about 2 microns in diameter, is seen to extend around the exterior of the shaft, occasionally accompanied by a hyphal strand. This type of distribution is called ectothrix. Sometimes similar hyphal strands are seen penetrating into the hair shaft as well. Cultures are necessary, however, to differentiate the types accurately, for the degree of inflammation is too variable to be a reliable index. Filtered ultraviolet radiation is a helpful adjunct to diagnosis, as hairs infected by M. canis or M. audouinii fluoresce a brilliant greenish-yellow. There are some pitfalls, however, in this examination: fluorescence may not begin at once; it may be destroyed by medication before cure has been attained; and it is almost always entirely absent in M. gypseum infections. Also, other substances like keratin, soap, medicaments, and dyes fluoresce so as to confuse the picture. The observer must be certain that the short stubs of hairs are the ones actually producing the fluorescence, and he can best prove that they are by extracting some of them from their follicles by forceps while under dark light, when it will be seen that the part of the hair which was within the follicle also fluoresces brightly. If these fluorescent hairs are extracted singly, and if several of them are used to inoculate the cultures, failure to obtain an uncontaminated, readily identifiable colony will be rare. Tinea capitis of the black-dot variety.—This type is so named because of a tendency for the follicles to be filled with dark-colored debris of hairs and fungi, causing a black-dotted appearance, although this characteristic is by no means always present. The infection is transferred from human to human, and thus often exists in epidemic proportions. It is caused either by Trichophyton tonsurans (synonyms are sulfureum and crateri-

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forme) or by Trichophyton violaceum or T. ferrugineum. The former predominates in the Americas, and the latter two predominate in Europe, Africa, and Asia. This type afHicts adults as well as children, but less frequently. Clinically it may be relatively noninflammatory at times and resemble seborrheic dermatitis, or it may cause moderate inflammation which slowly produces scarring, resulting in an appearance suggesting lupus erythematosus. Frequently there is an even greater degree of kerionlike inflammation, causing scarring and permanent alopecia. The hairs tend to break off within the follicular orifices, where blackened plugs are left, from which characteristic the disease acquired its "black-dot" nickname. For unknown reasons, the plaques in this disorder tend toward angulated perimeters, frequently forming polygons instead of ovals or circles. Unless marked inflammation occurs, this type of tinea capitis is usually resistant to treatment. Microscopic examination reveals the hair shafts to be invaded longitudinally by hyphal threads which tend to break up into boxlike or subspherical arthrospores, an arrangement known as endothrix involvement. Cultures are necessary to establish that this type of infection is present and to guide the prognosis. As there is no useful degree of fluorescence under ultraviolet radiation, this method is not completely reliable for mass examinations of children during epidemics, as was the custom before the black-dot type of tinea capitis was added to the local flora. Trichophyton tonsurans Malmsten 1845 grows slowly in culture, and varies so much in color and texture that formerly it was separated into several species. The surface of the colony bears only short mycelial threads, and is velvety rather than fluffy. The color varies from shades of tan, brown, or gray to a sulfur-yellow. The surface may show radial grooves, concentric folds, or other irregularities. Most strains produce a darkbrown or slightly reddish-brown color on the undersurface of the colony, but the pigment is not diffusible into the medium. Microscopically, only microconidia are usually produced, but they are larger and longer than those of Microsporum, and are often borne on an elongated stem resembling a short hyphal branch. Trichophyton violaceum Sabouraud 1902 grows very slowly in culture, remaining flat and moist on the surface for a long time, and begins early to produce a deep-violet color visible on both obverse and reverse. Later the surface may develop a thin layer of velvet and become extensively wrinkled. The organism seldom sporulates except on special media, but abortive attempts are seen as enlargements at the tips of some hyphae which branch irregularly to resemble the antlers of a deer, although not so well developed as in T. schoenleinii. Trichophyton ferrugineum (Ota) Langeron and Milochevich 1930 grows in culture in the same way as T. violaceum, but the color is a brilliant orange, both above and below. Sporulation is very rare. Some strains

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acquire a white, velvety surface, especially in specimens from the Belgian Congo (Van Breuseghem, 1950). Tinea capitis of a highly inflammatory type is occasionally caused by Trichophyton mentagrophytes, but as this organism is the most frequent cause of tinea barbae, it is described in more detail under that heading. Favus.—Caused by Trichophyton schoenleinii, favus is another type of ringworm of the scalp, although it often affects other areas of the body. Before the advent of modern antibiotic fungal therapy, favus was frequently so resistant to treatment as to persist, spreading slowly but actively, with much scarring from childhood, throughout the lifetime of a person, and to be transmitted through several generations of a family. It is transmitted directly from human to human, but only a small percentage of exposed persons acquire the infection. Its occurrence in several members of a family and in successive generations may well indicate that a susceptibility trait is transmitted genetically. The older descriptions of favus emphasized the presence of cup-shaped crusts called scutula, composed of dried exudate, pus, and hairs, varying in size up to 2 centimeters in diameter, and accompanied by a mousy odor. These characteristics are not constant, and apparently occur only under unhygienic conditions or when scalp cleansing is neglected. Microscopic examination of infected hairs shows endothrix involvement with the association of peculiar bubbles of air. Distinct fluorescence of the hairs appears under filtered ultraviolet radiation, but it is somewhat duller and more green than that in Microsporum infections. Trichophyton schoenleinii (Lebert) Langeron and Milochevich 1930 grows very slowly in culture as a white, slightly gray, or cream-colored colony, beginning with a moist, shiny, irregular surface and later tending to acquire a short, velvety fuzz of aerial hyphae. The reverse of the colony shows no characteristic color. Microscopically, spores are seldom seen, although occasionally what are probably microconidia occur, extremely irregular as to size and shape. The distal extremities of many hyphae become enlarged and branch wildly and profusely, resulting in structures vaguely resembling the antlers of a deer or moose, referred to as "favic chandeliers," more highly developed than those described for T. violaceum. Tinea barbae (ringworm of the beard) This rare disease almost exclusively affects men in close contact with domesticated animals, principally cattle. It is more common among dairy workers than among those who raise beef cattle because the former tend to rest their faces against the cows during milking. The same infection has been traced to horses, rabbits, and laboratory animals such as rats, mice, and guinea pigs. Although convenient, it is not strictly appropriate to discuss tinea

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barbae as a separate entity, for the same fungi frequently cause similar lesions in the scalp (see section on tinea capitis), and, not rarely, on arms or legs. The presence of rather coarse hairs seems to promote the infection wherever it occurs. All these lesions are markedly inflammatory, resulting in swelling, pain, and tenderness, and usually in pustulation and abscess formation, the equivalent of kerion as described for scalp infections. Bacteria are often significantly contributory, and call for supplementary treatment. Wherever they occur, the lesions almost always produce scarring and permanent loss of hair. Two species of fungi are principally involved in this type of infection. One is a variety usually included in the species Trichophyton mentagrophytes; it is characterized by a powdery or coarsely granular surface of the colony in culture, and produces considerable reddish-brown pigment on the reverse. {Mycologic description of this fungus is deferred until ringworm of the feet is discussed.) Trichophyton verrucosum Bodin 1902 is the fungus most frequently acquired by man from cattle. It grows slowly in culture, forming a waxy, glabrous colony whose surface is very irregular, so variable in color as previously to have been regarded as three different species (album, ochraceum, and discoides). On especially enriched media Georg demonstrated macroconidia typical of the Trichophyton genus, but on ordinary media there is little sporulation. Tinea corporis This disease can be caused by any dermatophyte fungus; in fact, it is frequently associated with tinea in other areas, especially the scalp, and is caused by the same organism. It is noteworthy that adults, who are seldom infected on the scalp by the Microsporum species of fungi, may easily acquire such infections on the glabrous skin. Clinically, the lesions begin as small macules, spreading in roughly circular fashion; after reaching the size of about 1 centimeter, they begin to clear in the center, creating the typical ringed forms from which the name "ringworm" is derived. The clearing apparently results from a degree of acquired resistance, which is, however, only temporary; often the center becomes infected again and again, until the lesions take on the appearance of a target. Usually the total number of spots is small, in sharp contrast with the exanthemata, and especially with pityriasis rosea and secondary syphilis, which are often mistaken for ringworm in their early stages. Itching is usually a prominent feature, and scratching serves to spread the infection. Microscopic study of scrapings taken from the actively progressing vesicular border of such lesions, and prepared with potassium hydroxide solution and heating, reveals branching hyphal threads of the fungi, tending at times to break up into box-shaped or rounded arthrospores.

34. Tinea capitis: noninflammatory (human) type. Usually caused by Microsporum audouinii. Upper left: graypatch ringworm. Middle left: same, with larger areas of involvement. Upper right: coalescence into large areas with much scaling. Lower right : almost total involvement of scalp. Lower left: appearance of infected hairs under filtered ultraviolet radiation (Wood's light). PLATE

35. Tinea capitis: inflammatory (animal) type. Usually caused by Microsporum canis or M. gppseum. Upper left: early mildly inflammatory plaque. Middle left: ringed forms involving scalp and eyebrow and extending over onto glabrous skin. Lower left: extensive involvement with severe inflammation and loss of all hair roots from follicles. Upper and middle right : deep, boggy, severe inflammation (kerion Celsi). Lower right : kerion with marked secondary bacterial involvement. PLATE

36. Tinea capitis: black-dot type and forms. Upper right and upper left: black-dot ringworm, usually caused by Trichophyton tonsurans or T. violaceum. Middle left: severe inflammation and kerion caused by T. tonsurans. Lower left: deep scarring granulomatous type (Majocchi's granuloma), caused by T. mentagrophytes from rabbit. Lower right : favus, caused by T. schoenleinii. PLATE

P L A T E 37. Tinea barbae and trichophytic (Majocchi's) granuloma: powdery, pigmented type. Usually caused by Trichophyton verrucosum or T. mentagrophytes. Upper left: involvement of moustache region. Middle left: involvement of chin in dairyman. Lower left: deep cicatrizing granulomatous infection of dorsum of wrist in rabbit handler. Upper right: deep inflammatory cicatrizing form on leg, acquired from white laboratory rat. Lower right: deep granulomas on hand and lower leg, from cattle.

PLATE 38. Tinea corporis. May be caused by any dermatophyte. Upper left : showing that there is not always a ring formation ; sometimes the central part does not clear and continues to appear eczematous. Middle left: typical ringed lesions, with active borders clearing in center. Upper right: after a time center may become reinfected, resulting in "target" formation. Lower right : target effect well developed. Lower left : chronic hyperkeratotic form common in Trichophyton rubrum infection.

39. Tinea cruris. Most often caused by Trichophyton mentagrophytes or Epidermophyton floccosum. Upper left: note lack of symmetry and rounded lesion. Upper right: sharply outlined serpiginous border extends beyond intertriginous surfaces. Middle left: smaller papular areas of involvement. Lower left: in females there is less tendency to clearing in center (contrast with upper right). PLATE

P L A T E 40. Tinea pedum and manuum: chronic, hyperkeratotic, mildly inflammatory type. Usually caused by Trichophyton rubrum. Upper left: thick hyperkeratosis. Upper right: moderate hyperkeratosis. Middle right: thick hyperkeratosis of palms and dorsa of hands (note also involvement of thumbnail). Lower right: moderate hyperkeratosis of palms only. Lower left: involvement extending up legs.

41. Tinea pedum and manuum: acute, highly inflammatory type. Usually caused by Trichophyton mentagrophytes or Epidermophytonfloccosum.Upper left: inflammatory plaques on sole. Upper right: vesicular and denuded areas on toes. Middle right: vesicular denuding form on soles. Lower left: vesicular form on palm. Lower right: vesicular form with secondary bacterial invasion. PLATE

42. Tinea of the nails (onychomycosis). Most commonly caused by Trichophyton rubrum or T. mentagrophytes. All except lower left are typical forms. Lower left: paronychia, seldom of dermatophyte origin but often caused by Candida albicans or by bacterial infection. PLATE

43. Dermatophytid reactions. Allergic reactions to fungi, the so-called " i d s . " Upper and middle left: allergic vesicular eruptions of hands caused by active dermatophytosis of feet. Lower left: note active infection near scrotum toward left (caused by Epidermophyton floccosum), and morbilliform id eruption on thigh toward right. Upper right: note severe active tinea capitis and allergic erythema multiforme-like id eruption on back. Lower right: psoriasiform id eruption on lower chest and abdomen. PLATE

P L A T E 44. Tinea versicolor and erythrasma. Upper left and lower right: most common form, in which involved rounded areas are darker than surrounding normal skin. Lower left: reversed situation, in which involved areas are lighter. Middle left and upper right: erythrasma, now considered a bacterial rather than a fungal infection.

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Tinea imbricata This special type of tinea corporis, also called tokelau, is caused by Trichophyton concentricum. According to Halde (1964), it occurs in many South Pacific islands, Ceylon, India, Southeast Asia, and China, as well as in certain isolated rural areas in Central America and tropical South America. It is seldom acquired by persons living in cities. No age is

Fig. 13. Tinea imbricata. Upper left and upper right: early lesions showing imbricated, targetlike development. Middle right: involvement of back of hand. Lower left and lower right: Diffuse, extremely hyperkeratotic type in practically universal distribution over body.

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exempt. Although it is definitely contagious, many adequately exposed persons remain uninfected, and familial multiple infections seem to indicate a genetically transmitted susceptibility factor (Schofield). Clinically, tinea imbricata is characterized by an elaborate series of concentric circles of desquamating skin, the scales remaining adherent at the periphery of each circle with their free borders toward the center. The lesions slowly expand peripherally, without much inflammation and very seldom with vesiculation to coalesce and form serpiginous and polycyclic designs. The trunk is most commonly affected, but the entire body is often covered, excepting at times the axillary and pubic areas and the hair of the scalp. Hairs or nails are not invaded by this fungus. Trichophyton concentricum Blanchard 1896 grows slowly in culture and forms an irregularly heaped-up colony covered with short hyphae, white, light brown, or gray in color. No distinctive spores are produced, and identification must be by the irregular abortive attempts to form conidia and by observation on special media by expert mycologists. Tinea cruris (ringworm of the groin) This disease includes includes superficial fungous infections in other intertriginous areas such as the axillae, the inframmary folds, the umbilicus, and the intergluteal fold. More than half the cases of fungous disease in these regions, being caused by a nondermatophyte, Candida albicans, are not properly classed as tinea; the disease is usually referred to as moniliasis (see chap. 13). Obviously disorders in these areas are strongly influenced by the tendency to sweat profusely. Actual ringworm is often differentiated from simple intertrigo or bacterial infection by the presence of raised, vesicular, actively progressing, rounded borders extending beyond the areas of contiguous contact of the skin surfaces, and by the lack of symmetry. Also significant is the fact that dermatophytes usually avoid the scrotum and the labia, where the keratin which they like is too thin. It is convenient to describe one species of fungus, Epidermophyton floccosum, in connection with tinea cruris because it is found more often in these areas than in any other part of the body, although it also causes trouble between the toes. This fungus, however, is not the most common cause of tinea cruris; in most regions of the world it is outnumbered in incidence by both Trichophyton rubrum and T. mentagrophytes. Epidermophyton floccosum (Harz) Langeron and Milochevich 1930 grows fairly rapidly in culture, producing irregularly folded colonies with short aerial hyphae, in general of a greenish-gray color. Considerable dark-brown coloration is seen from the reverse of the culture. The surface is powdery because of the presence of many spores. Microscopically, these spores are seen to be thin-walled and more oval than elongated in cross section; they resemble beaver tails, with only two or three cross walls. They are often borne in bunches on short conidiophores.

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Tinea pedum and manuum (ringworm of feet and hands) Acute inflammatory type.—The interdigital areas in hyperhidrotic feet very frequently become infected with an acute, vesicular, denuding fungous disease very similar to tinea cruris, which may also arise in or spread to the soles or dorsal areas as well. Most people occasionally have at least a little of this trouble in hot weather. T h e infection may burrow underneath the thick keratin layer of the sole until it is completely denuded. Secondary bacterial contamination is common. T h e hands may be involved in a similar process, but much less frequently, and almost never unless the feet are also involved. This form, although clinically severe, usually responds rather quickly to treatment. T h e interdigital areas themselves may be affected in a manner clinically similar to the above by ammoniacal change in occluded perspiration, with or without the addition of bacterial action and exclusive of fungi, but the infection seldom extends beyond the surfaces actually in contact with each other. A similar condition is often caused by Candida albicans, sometimes extending beyond the occluded region onto the dorsum of the foot, but seldom involving the sole. Microscopic examination of specimens preferably taken from vesicles, after treatment with K O H and heat, reveals the hyphae of the fungi as branching filaments, often breaking up into arthrospores. Sometimes it is possible to differentiate dermatophytes from Candida albicans by direct examination alone, if the typical blastospores of the latter are also seen. T h e dermatophytes most commonly encountered in the acute type of tinea of feet and hands are Trichophyton mentagrophytes and, less frequently, Epidermophyton floccosum. Trichophyton mentagrophytes (Robin) Blanchard 1896 grows fairly rapidly in culture and produces colonies exhibiting considerable variation; because of this variation, the fungus was separated for many years into several species. Indeed, it is still so separated by some authors, particularly in Europe, although they usually do not agree on the dividing lines between the separate "species." There are at least two fundamental types representing the extremes of variability, but all gradations between them occur and are frequently obtained by single-spore isolations from either polar type. It is therefore our preference to maintain T. mentagrophytes as a single species with variants. One extreme is represented by a snowy-white colony of fluffy, "wellcombed," long mycelium, producing no color as viewed from the reverse. This form is the one most commonly isolated from toe webs and soles, as well as from hands and groins. T h e other extreme is a flat colony bearing almost no mycelial threads, but liberally covered with a coarse powder, light tan to brown, and producing a varying amount of reddish-brown pigment visible from the reverse. T h e depth of the pigment is proportional to the concentration of powder, truly fluffy colonies having none

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(in contrast with T. rubrum), and generously powdered ones never being free of it. Microscopically, the cottony type of colony does not produce many spores; usually only a few microconidia are to be seen, tending to be globose or slightly oval and borne along the sides of the hyphae on very short necks. The powder from the other type is seen to be composed of myriads of spores, sometimes all of the microconidial type already described, sometimes borne in grapelike clusters, with large numbers having broken away to float free in the liquid of the preparation. Some strains produce macroconidia, occasionally in profusion; they are elongated up to 8 microns in diameter and 30 microns in length, round-tipped, somewhat clindrical, and thin-walled, and present a few cross walls, at which points the cylinder may be slightly constricted. This variety also commonly reveals spirals, resembling tightly or loosely wound coil springs, sometimes in large numbers. Most of the strains acquired from animals are of this powdery, pigmented variety, already mentioned in connection with tinea of the beard, scalp, or arms of the highly inflammatory, hair follicle-destroying, severely scarring variety. When hairs are invaded the pattern is predominantly ectothrix. Chronic hyperkeratotic type.—In strong contrast with the acute form described above is an extremely chronic, nonvesiculating, mildly erythematous, scaling, hyperkeratotic eruption, often limited principally to the soles and sometimes affecting the palms, extending partly toward the dorsal surfaces at the edges. The thickened, dry, hyperkeratosis often produces deep, painful fissures. In approximately 20 percent of the cases a peculiar lack of symmetry is observed (heretofore not adequately explained except on theoretical grounds, to be discussed in the section on immunology); for example, one hand or one foot may be involved for long periods, up to many years, without the other hand or foot ever showing any sign of infection. This clue is valuable, because other hyperkeratotic disorders tend to be more symmetrical. This clinical picture is almost always caused by Trichophyton rubrum, although occasionally duplicated by other dermatophytes. Often in conjunction with the above syndrome there is infection of the inguinal region, the intergluteal cleft, or the buttocks, closely resembling tinea cruris; vesiculation is uncommon, however, and, instead of appearing rapidly and becoming acute, tends to be very chronic and to enlarge slowly. In certain hypersusceptible individuals many large areas of the body may be affected while others contiguous to them remain entirely normal, resulting in the most bizarre patterns, slowly changing in configuration over many years. Occasionally the entire body surface is involved, and then the infection resembles tinea imbricata rather closely. Even the scalp and beard may acquire a fungal folliculitis. A rather unusual eruption on the legs, characterized by perifollicular

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inflammatory nodules, was described in 1954 by Wilson, Plunkett, and Gregersen, and almost simultaneously by Cremer. Microscopically, these nodules were small perifollicular granulomas caused by penetration of bits of hair infected by T. rubrum through a rupture of the follicular wall. Thompson (1938) and later Naida and Holman presented some evidence tending to convict fungi, particularly T. rubrum, as the cause of, or as contributing to, thromboangiitis obliterans and other occlusive vascular disorders, probably through an allergic mechanism. Convincing proof has not yet appeared. Trichophyton rubrum (Castellani) Sabouraud 1911 grows moderately rapidly in culture, and produces colonies usually exhibiting a white, wellgroomed, cottony tuft of long mycelial threads. Sometimes there is a pink or red tint, especially in some more flattened strains, and when some powdery surface develops. After the first few days most colonies begin to show a red or purplish coloration in the center as seen on the reverse; this pigment, becoming even more pronounced as development proceeds, diffuses into the agar. The more powdery the surface, the deeper the wine color, but even the whitest and fluffiest colonies also produce it well (in contrast with the similar fluffy form of T. mentagrophytes). Microscopic examination of cultures of T. rubrum reveals microconidia borne along the sides of the hyphae, usually more elongated and pearshaped than the more globular ones characteristic of T. mentagrophytes. The white, fluffy colonies do not produce many microconidia, whereas the more powdery ones show them in quantity, together with macroconidia in many strains. The latter are never so well developed or so numerous as in T. mentagrophytes, tending to be shorter, with fewer cross walls, and showing all sorts of variations and abortive forms. Tinea of the nails (onychomycosis) Tinea of the nails may occur alone as the only manifestation of fungous infection, or may be associated with mycotic disease elsewhere, most commonly of feet or hands. The infection usually begins at the tip of the nail, and progresses slowly proximally underneath it, separating it from its bed and accumulating an ever-thickening layer of detritus resembling fine, firmly packed sawdust. Often the process continues all the way to the root of the nail, but it may extend through only a part of this distance and remain stationary at that point for a long time. The nail plate becomes fragmented over the more heavily involved areas near the tips, and often is almost completely eroded away. With the exception of Trichophyton concentricum, any dermatophyte may infect the nails. T. rubrum and T. mentagrophytes are by far the most common causative agents. Paronychia, causing inflammation of the nail root, and onycholysis, resulting in separation of the nail from its bed, may be caused, or con-

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tributed to, by fungi, but not usually by dermatophytes. (See chap. 13 for a discussion of these conditions.) PATHOLOGY T h e pathologist is seldom called upon to establish the diagnosis of dermatophytosis, especially if the patient has the attention of a dermatologist who is microscopically examining freshly acquired specimens and using cultural methods. Fungal hyphae may easily be distinguished in the keratin and the prekeratinizing parts of the epidermis in routine H & E stained preparations, and even more distinctively by the PAS method. Histopathologic study of specimens from the inflammatory type of tinea capitis has revealed the characteristic fungous invasion of the hair follicles, either as an ectothrix mantle of globose spores, or as the endothrix invasion of the hair shafts by hyphal elements breaking u p into arthrospores, according to which one of the causative fungi is involved. In the nodular perifollicular granulomatous lesions of the legs, usually caused by T. rubrum, a mass of granulomatous infiltrate is seen around a follicle whose wall has undergone some necrotic destruction. T h e reaction is predominantly chronic, and the infiltrate is composed of epithelioid cells, plasma cells, giant cells, and fibroblasts. Fungal spores are seen packed outside the hair shafts, as well as in chains invading the cortex. Some spores are found at a considerable distance away, within the corium, stimulating the tissue reaction. T h e serial sections of nails that have been evulsed in the treatment of onychomycosis reveal that the fungi have penetrated much deeper proximally than inspection of the nail in situ would have suggested. W h e n a nail is apparently involved only halfway to the base, the microscope has shown fungal hyphae extending proximally to a spot within 1 mm of the point of origin of the nail. It is therefore futile to expect an externally applied medicament to penetrate deeply enough to kill all the fungi. DIFFERENTIAL

DIAGNOSIS

N o clinician can differentiate fungal skin disorders from those not of fungal origin by visual means alone. N o experience is more humbling for him than the checking of his clinical impressions by direct microscopic study of bits of tissue taken from typical lesions, or by cultural methods. T h e greatest of all handicaps in the treatment of skin diseases is the tendency of nondermatologists, most of whom overestimate their own clinical acuity, to treat patients without establishing the diagnosis. T h i s procedure is entirely unwarranted, for one or two minutes of microscopic study is often enough to remove all doubt as to the diagnosis. T i n e a capitis must be differentiated from alopecia areata in its early stages, trichotillomania, seborrheic dermatitis, psoriasis, pyoderma with

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or without pediculosis, tinea amiantacea (not truly of fungal origin), trichorrhexis nodosa, and monilethrix, and even at times from secondary syphilis. The scarring that accompanies some forms of tinea capitis, notably favus and the black-dot type, may clinically be confused with pseudopelade and folliculitis decalvans, and even with lupus erythematosus of the discoid type. The extraction and proper microscopic examination of a few hairs from an actively involved area often facilitate the solution of a difficult diagnostic problem. Tinea corporis must be differentiated from nummular eczema, pityriasis rosea, secondary syphilis, psoriasis, impetigo, and ecthyma. Although tinea corporis usually develops fewer lesions, and develops them more slowly, than these eruptive diseases, microscopic study is absolutely necessary in many instances. Tinea cruris deserves special attention because the selection of appropriate therapy depends entirely on accurate diagnosis of the causative factor. When the disease is caused by a dermatophyte, oral treatment with griseofulvin is quickly effective, and avoids subjecting the delicate tissues in inguinal, anal, and genital areas to irritating external medicaments. But when tinea cruris is caused by Candida albicans (moniliasis), this treatment does no good, and in many instances seems to be harmful, whereas appropriate topical therapy brings prompt relief. Intertrigo with or without added bacterial infection demands yet another therapeutic approach. The presence or absence of dermatophytes in the affected areas cannot be determined by clinical inspection alone. Tinea of the feet and hands actually accounts for only about one-third of dermatologic disease in these areas. Dyshidrosis, pompholyx, contact dermatitis, intertrigo, moniliasis, neurodermatitis, psoriasis, stasic dermatitis, and other circulatory disturbances may produce lesions resembling those characteristic of fungous diseases, even to the most experienced clinician. With the advent of griseofulvin, a remedy so efficient for the treatment of true dermatophytosis and so useless for all other conditions, laboratory confirmation or denial of the clinical impression is mandatory. Tinea of the nails is even more difficult to differentiate from nonfungal nail disease. Psoriasis is the most easily confused disease, but nail dystrophies, due to trauma or to circulatory stasis, also show similarities to tinea of the nails. Griseofulvin may help actual dermatophytic infections of the nails, but only by oral administration in high dosage for many months, at considerable trouble and expense to the patient. It is foolish to embark upon so lengthy a treatment without first establishing dermatophytic fungi as the cause of the infection. MYCOLOGY The mycologie aspects of dermatophytosis have been discussed in the appropriate context in the preceding paragraphs. Further details are pre-

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sented in the chapters on fundamental mycology and laboratory methods (see Part IV). IMMUNOLOGY Most, if not all, human beings become infected at some time or other by dermatophytes, often repeatedly throughout life. At such times the natural keratinization process is continually producing scales and hair and nail fragments. These particles, which are shed into the environment, are loaded with viable fungus spores. Also, many of the animals commonly kept as household pets are capable of acquiring fungous infections and transmitting them to their masters. Moreover, some species of dermatophytes apparently are widely distributed over the globe in the soil, where they grow saprophytically. Obviously, no one can live without frequently and repeatedly having his skin brought into contact with these pathogenic organisms. T h e degree of virulence or pathogenic ability possessed by these fungi is subject to some variation, but not over a wide range. At first glance, therefore, it would seem inevitable that almost all human beings would, at one time or another, be infected with many types of fungous diseases. Such widespread infection does not occur, however, because many factors, both known and unknown, create all conceivable variations in the range of individual susceptibility. T h e variations in the virulence of the causative organisms have already been noted; there are also mechanical and immunologic factors which deter infection. Mechanical factors Mechanical factors often act as adequate barriers to the acquisition of a dermatophytosis. Frequent bathing with soap and water removes a large proportion of the infectious elements that fall upon the skin before they are pathogenically established, and also diminishes the quantity of organic residues from perspiration, on some of which fungi feed. Persons whose skin is naturally thin, with little thickness of the keratin layer where fungi flourish, are more difficult to infect. Dry skin, which sheds its keratin rapidly, is more resistant than moist and oily skin. Occupations necessitating frequent wetting of the skin, especially with liquids containing nutritive food elements, promote infection. T h e keratin in human hair apparently is too dry and inert to attract and support fungi, except for the parts that are still within the follicle or extend only a few millimeters beyond the orifice. Long-haired girls therefore acquire tinea capitis much less frequently than short-haired boys, because the organisms that fall upon their heads reach the scalp much less easily. This factor makes a difference even in boys, for the clipped, comparatively short-haired nape is a favored initial spot for the infection. Although there are some fatty acids in sweat which possess fungistatic

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abilities, excessive perspiration actually promotes infection, especially when occluded from adequate evaporation as in feet, axillae, groins, and submammary folds. Perhaps in these areas the fungistatic fatty acids are somewhat neutralized by ammonia, resulting from the bacterial degeneration of urea. Thick-soled, heavy, unventilated shoes, long considered stylish by the male sex, make men more susceptible to infection than women, who wear mere "soles and straps." Obesity causes deep folds between the buttocks and in groins and axillae which easily become macerated; the situation is usually worsened by the wearing of tight girdles. Immunologic factors Natural immunity.—The dermatophytes grow well on skin, hair, nails, feathers, and other keratin materials, but this preference is not the reason for their failure ordinarily to penetrate beneath the basal cell layer of the epidermis, or, in fact, to go even that far. Blank and Roth (1959) and Lorincz et al. (1958) have demonstrated that normal human serum contains an efficient fungistatic agent against these organisms, and that the diffusion outward of this substance keeps the fungi at their superficial level. This natural immunity factor, however, does not completely prevent infection, but simply limits the depth to which it can penetrate in normal individuals. Although difficult to prove statistically, and contrary to the results prognosticated on the basis of extensive animal experimentation, it seems evident that a high proportion of human beings are naturally entirely resistant to most dermatophytes. For example, even in communities where few measures are taken to combat the epidemic form of tinea capitis, the percentage of children who become infected always remains small, and the epidemic eventually reaches a leveling-off stage. It is difficult to accept the thesis that this favorable situation depends wholly on mechanical or virulence factors; the inference is strong that susceptibility is by no means universal, and may depend on an individual abnormality. Another example is furnished by studies of human infection by Trichophyton rubrum. Of sixty-one persons so infected continuously over periods varying from one to twenty years, Wilson, Levitt, and Plunkett (1952) found that not one spouse had acquired the disease, even though obviously living in a sea of spores of the organism for long periods. Since then two such pairs of marital partners have been found. From this observation no accurate percentage can be derived, but it is probably correct to state that not more than one in thirty to fifty persons is capable of becoming infected by this fungus. It appears unlikely that so high a degree of resistance can be explained by any mechanism of specific acquired immunity derived from previous acquisition of the disease in an unrecalled form. This resistance thus seems to be of the natural variety, leading to the conclusion that those who do become infected either lack this normal factor, or pos-

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sess some abnormal characteristic making them peculiarly susceptible. T h a t this abnormality may even be genetically transmitted also seems possible, for two children (blood relatives) in the families of the sixty-one patients acquired the infection even while the spouses did not (ibid.). T h e infection has since appeared in other blood relatives. T h e above views were challenged by Desai (i960), who found both spouses infected by T. rubrum in almost half of the pairs studied. When he demonstrated several such pairs to Wilson in India, however, it became obvious that the infection was almost always present, and was most severe, on the abdominal skin under the large ball of folded cloth which forms in the conventional clothing of many natives of India, the sari of women and the dhoti of men. Friction and perspiration created a localized susceptibility, which does not duplicate the chronic form we encountered in the United States. Lewis, Hopper, and Scott (1953) observed widespread T. rubrum infections in three patients with coexistent lymphoblastomas, but this phenomenon must occur only occasionally. Diabetes, which does predispose to T. rubrum infection, has been observed in connection with Cushing's syndrome, of both the tumor type and the form caused by the administration of steroid hormones for other diseases (Canizares et al.; Nelson et al.). It would seem, therefore, that T. rubrum prefers tissues high in glucose content. (Some years ago Rothman stated the reverse of this opinion, but later admitted that his statement had been misinterpreted.) This explanation, however, may be too simple; it may be that the fungus likes tissues that are involved in an abnormal metabolism of carbohydrates or polysaccharides, instead of glucose. T h e process may be similar to those recently publicized as part of the diabetic syndrome, but unrelated to glucose metabolism and not controlled by insulin. Such processes may even be present for years before diabetes is diagnosable by the present tests for abnormal glucose metabolism, and the fungus may be able to recognize their presence much earlier than diagnosticians. It is noteworthy that a severe T. rubrum infection may persist in one hand or one foot of a patient for years without the other hand or foot ever becoming infected, suggesting that the postulated abnormality in carbohydrate metabolism may not be systemic, but may reside at the tissue level or the cellular level in some regions in the body while others behave normally. Eli Lilly and Company have pointed out that the paper strips chemically prepared to test urine for glucose do not always have to be so used, because many patients can cause the paper to reveal heightened blood sugar by simply holding it between thumb and forefinger, where insensible perspiration effects the change; some persons can effect the change consistently with one hand but never with the other. We have tried, thus far without success, to use this test to prove that it is related to unilateral T. rubrum infection.

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Favus, caused by T. schoenleinii, has often persisted throughout a patient's lifetime and been transmitted through several generations within the family. If a large percentage of persons in the population as a whole were susceptible to so extremely persistent a disease, favus would almost inevitably have become very common. Here again an inherited defect in natural resistance seems a likely explanation. Similarly, certain persons seem to attract Malassezia furfur infection almost magnetically, whereas most people apparently are naturally immune. This infection also exhibits familial concentrations, suggesting that a hereditary factor may be of controlling importance. Possibly natural immunity is simply a characteristic of general good health, and susceptibility occurs only as an accompaniment of abnormality, either as an inherited factor or as the result of disease. For example, diabetes predisposes to moniliasis, as do vitamin B deficiency and the oral administration of certain antibiotics. Parathyroid disease may make a person susceptible throughout life to moniliasis. Obviously, at least as much effort should be directed toward understanding the defects in natural resistance to disease, as toward searching for chemicals capable of curing infections by killing the offending organisms. In fact, fungicides alone are probably only temporarily helpful in many disorders, because the still-susceptible person may soon become reinfected after their discontinuance. In contrast with the above, there are some fungous infections to which most, or perhaps all, persons may be originally susceptible, such as tinea pedis caused by T. mentagrophytes. Numerous people have this infection continuously over many years, while others acquire it frequently and clear it relatively quickly each time, seemingly because of a resistance factor which is easily developed or regenerated by the infection but then disappears, or at least declines below an effective level in the interim between infections. Some of these persons seem eventually to become persistently immune. A similar fluctuation or alternation in immunity and susceptibility is seen in the ordinary type of tinea corporis, but here it is a temporary variation in tissue resistance. An actively advancing border leaves behind an area that clears itself of the infection and cannot be reinfected for a time; it soon loses this resistance, allowing a new center to start which then expands and clears again centrally, resulting in a target of concentric rings. Yet another natural mechanism is always working to clear a dermatophyte infection, although by no means always successfully. It is the effect of a process that Kligman described thoroughly for hair infections, and Wilson named the "epidermal effluvial current." In man and animals the epidermis proliferates continuously and pushes the epidermal cells thus produced toward the external surface, to be shed eventually as dried kera-

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tin squames. This process goes on just as productively within the hair follicles as it does on the flat surfaces of the skin. The hair itself is produced by this activity on the part of the epidermal cells of its root at the papilla. The basal cells of the external root sheath are equally productive; however, they do not contribute their keratinized product to the hairs, but to the inner root sheath, whose two layers are known as the sheaths of Huxley and Henle. This keratin material also grows outward at the same rate as does the hair, appearing at the mouth of the follicle as a ring of keratin surrounding it before being shed. Thus, not only the hair itself but all the keratin and its precursors which are produced within the follicle are carried outward at the same rate, and there is no sliding of one layer abruptly over another. This process is the epidermal effluvial current. T o succeed in parasitizing a hair, a fungus must be able to grow downward into the follicle at a rate more rapid than the outward rate of the epidermal effluvial current. Also, as a fungus does not ordinarily penetrate beyond the confines of the epidermis unless fortified by bacterial allies or by allergic hypersensitivity, it is always contained entirely within structures that are moving toward the exterior at this same rate. Hence, to maintain its parasitism of the follicle, the fungus must continuously grow downward into the follicle at a rate at least equal to or exceeding the epidermal effluvial current. Figuratively speaking, it must continuously swim upstream to avoid being carried out to sea and lost. If the fungus falls behind sufficiently in its growth rate, the follicle automatically clears itself of the infection. It does so regardless of whether the hair shaft itself is discharged as the result of the natural cycle, or becomes epilated by other means, for the epidermis of the root sheath maintains the outward current at the same rate even when the hair shaft is not present, unless it is in a totally resting state, and then no keratin is being produced, nor is there any present, to support the growth of the fungus. This concept explains many otherwise puzzling aspects of the therapy of tinea capitis. Cure spontaneously occurs if the rate of hair growth is sufficiently increased, or if the ability of the fungus to grow inward becomes sufficiently slow. The rapidity of growth of the advancing filaments at the edge of a fungus colony depends to a significant degree upon the amount of fungus present for its support in the central parts of the colony and upon its degree of health. Many factors may impair the health of the fungus and thus slow its growth enough to allow a cure to occur. Some of them are undoubtedly inherent in the fungus itself, and the cure appears to be spontaneous even in the absence of any immunologic resistance on the part of the host. Closely clipping the scalp and cleansing it frequently and vigorously with soap and water are sufficient in many instances to tip the balance in favor of cure. Also, a fungicide does not have to penetrate to the depths of the follicles and kill all the fungi contained therein to

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contribute to a cure; it need only maintain sufficient fungistatic effect upon the surface, and perhaps to a certain depth, to keep the penetration rate of the parasite less than the rate of the epidermal effluvial current. The fungicide can also prevent the infection of new follicles. If this effect is maintained long enough over the entire scalp, all the follicles will clear themselves. The same mechanism is active in the same way in nails, except that it is a great deal slower and is exerted on one side of a concave surface instead of on the entire periphery of a circle, as in a hair. Acquired immunity.—When tinea capitis is associated with marked inflammation, as in kerion Celsi, the prognosis is good. The infection seems to burn itself out, and the patient is almost never reinfected. This observation suggests the development of a permanent immunity of a specific and acquired type. Significantly associated with this acquired immunity is the development of an allergic hypersensitivity (discussed in the paragraphs that follow). Trichophytin reactions.—From cultures of dermatophytes of any species, extracts called trichophytins can be made. They are of value in certain testing procedures and occasionally in the treatment of disease. It has usually been concluded that the product is identical no matter which species of organism is utilized. In other words, trichophytin is "group specific" rather than "species specific." In sensitive individuals the intracutaneous injection of trichophytin produces either an immediate wheal (urticarial) response or a delayed (tuberculin-type) reaction reaching its peak in about forty-eight hours. The delayed, tuberculin-type reaction has received the larger amount of attention, and is what is usually meant by the expression, "positive reaction to trichophytin." As stated above, this reactivity develops in the skin of patients with tinea capitis when kerion supervenes, and hence is closely associated with recovery. This sensitivity, however, endures long after cure has been obtained, perhaps for the life of the individual. As such patients rarely become reinfected, it is tempting to accept as fact that this reactivity implements immunity. In coccidioidomycosis the parellelism is even more closely documented, but it is still not possible definitely to connect the two, for there are many more gaps in our knowledge of dermatophytosis. Hypersensitivity to trichophytin is also present in marked degree in many patients possessing other dermatophytoses, especially of the acute, inflammatory, vesicular types such as tinea pedis or tinea cruris. In fact, it seems certain that a substantial proportion of the acute inflammation usually present in these disorders results from allergic hypersensitivity to the products of the invading fungus, which must be closely similar to or identical with trichophytin. The vesiculation produced by this mechanism obviously helps to clear the body of the infection, for it separates

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the keratin and prekeratin layers almost anatomically from the rest of the epidermis, and leaves no keratin to support further fungal growth. Even though this type of disease usually is easily cleared, indicating the value of the specific acquired resistance factor, the patients may subsequently be reinfected over and over again, as soon as new keratin is produced, even though the hypersensitivity persists apparently unchanged throughout the years. An immunity of this kind is obviously neither perfect nor complete. Dermatophytid reactions.—In association with a dermatophytosis in a localized area such as feet, groins, or scalp, an erythematous, papulovesicular eruption frequently develops at a distance from the original focus. The eruption may be localized or generalized, mild or severe. It is caused by the dissemination of fungous elements or products from the actively infected focus by way of the bloodstream. In individuals so affected, hypersensitivity to trichophytin of the delayed tuberculin type is the rule; in fact, it is a requisite for accepting the eruption as a trichophytid. Although the hypersensitivity probably helps the patient to throw off the actual infection, it is frequently much more uncomfortable than the original disease. All active fungicidal treatment must be abandoned to reduce the absorption of dead fungous derivatives and thereby ameliorate the allergic reaction, and gentle antieczematous measures must be substituted, together with temporary support by antiallergic drugs such as antihistamines and steroid compounds. Specific desensitization and maintenance in a desensitized state by cautiously repeated injections of trichophytin in appropriately increasing amounts may be necessary in isolated instances. The imediate wheal reaction to the intracutaneous injection of trichophytin is common, and is considered by many authors to be as specific and meaningful as the delayed tuberculin-type reaction. They believe the two reactivities are closely associated, and are, in fact, different stages of the same process. When hypersensitivity develops, according to their thesis, the first manifestation is the ability to react with the delayed, tuberculintype response. This ability is owing to antibodies that are developed and fixed to the cells of the skin. As the tuberculin-type reactivity cannot be transferred through serum to another individual, and does not pass the placenta, the antibodies are not present in the circulating blood, at least not in the serum. Later, however, as the process of hypersensitivity develops more fully, they become detached from the cells and, being then transferable, circulate with the blood. Thus they confer upon the individual the power to react to the intracutaneous injection of trichophytin with the immediate wheal response. This thesis is an appealing one, and conforms to much investigational work with allergens derived from foods, danders, protozoa, animal parasites, rickettsiae, viruses, and bacteria. But these substances are uniformly of a protein nature, whereas trichophytin is an almost pure polysaccharide,

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and it is not necessarily correct to expect substances so dissimilar to react identically. There are, indeed, several discrepancies in this concept which need clarification. Trichophytin, like coccidioidin and other antigens derived from fungi, is not completely antigenic in its own right. In other words, repeated injections of trichophytin into normal persons cannot induce the ability to react to its subsequent intracutaneous inoculation by the production of the delayed tuberculin-type response. It is possible, however, to induce the immediate wheal reactivity. As the former is considered to be the first of the two stages in the development of hypersensitivity, how can the immediate wheal type occur without being preceded by it? Trichophytin, the only product derivable from dermatophytes growing in culture, is admittedly not completely antigenic. Thus fungi growing on the human body in an actual infection must produce a completely antigenic product differing from trichophytin, for hypersensitivity is produced under these circumstances. As the entire cutaneous surface becomes hypersensitive and reactive at the same time, this antigenic substance must in some manner circulate in the bloodstream, whence it must be extracted and utilized as a stimulant by the body cells that produce specific antibodies, a function usually attributed to the reticuloendothelial system. The skin is relatively poorly supplied with reticuloendothelial elements of the type usually credited with this ability. Are we to assume that antibodies are formed in spleen, liver, lymph nodes, and other tissues rich in reticuloendothelial elements as a result of this stimulant, and then transported quantitatively to skin cells to become fixed there suddenly and permanently? Must not these antibodies circulate in the blood after they are produced in order to get to the skin? If so, why do we not observe the immediate wheal reaction to intracutaneous testing first, or at least early in the test, even for a short time, as this reaction to circulating antibodies is the characteristic one? Why must we attribute to nature an illogical process of fixing antibodies to the skin at first, and only later releasing them to circulate? Such a process, though not entirely unthinkable as an aid to the body in resisting an invasion of fungi into the skin itself, as in dermatophytosis, is utterly incomprehensible as a method of resisting pulmonary infection, as in the deep mycoses, where effective immunologic resistance does develop and is associated with skin-test reactivity of the delayed, tuberculin type, (antibodies fixed to skin) but never consistently with the urticarial, immediate wheal reactivity (circulating antibodies). It is easier to believe that the antibodies involved in the delayed tuberculin-type response do circulate when necessary, and that our tests have simply not as yet revealed them there. Perhaps they reside in cells that can circulate and carry them, such as the lymphocytes. The possibilities here may be seen at once by asking how likely one would be to find a fire engine in a routine sampling of the traffic arteries

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of a city, and observing in contrast what happens when an actual fire is reported. T h e antibodies may not be fixed to the skin at all, but may be called there from elsewhere in response to the injection of the antigen. In another form of allergic hypersensitization (induced by contact of the skin with topically applied chemicals), similarly nontransferable by serum and hence considered owing to antibodies fixed to the skin, Haxthausen (1942) has shown in experiments on two pairs of identical twins that the antibodies were not fixed to the skin. Skin from the sensitized partner lost its reactivity when transferred to the nonsensitized partner, and skin from the latter acquired reactivity upon transfer to the former. It seems better at present to consider both reactions as separate entities, and not as stages of the same process convertible one into the other. T h e delayed tuberculin type of reactivity may be associated with immunity in some way; the immediate flare reaction probably is not. This tentative conclusion parallels experience in coccidioidomycosis and other deep mycoses. Persons chronically infected with Trichophyton rubrum react to trichophytin much more frequently with the immediate wheal than with the delayed tuberculin response. It is significant that they also fail to resist the disease; even the erythema that accompanies their infections is consistently minimal, and the disease persists for many years. Vesicular reactions, which could help the body to throw off the infection, are uncommon, and trichophytid reactions are very rare. None of the attempts to render trichophytin completely antigenic by tuberculosis lipoid attaching it to other substances, such as Mycobacterium or proteinlike materials, has succeeded in subsequently inducing the tuberculin type of sensitization, nor has any degree of immunity been observably conferred. Furthermore, no notable success has attended efforts to induce the delayed type of trichophytin reactivity in persons infected with Trichophyton rubrum. in the typical highly resistant form by infecting them with T. mentagrophytes, efforts that, it was hoped, would enhance the possibility of acquiring specific immunity. THERAPY In most cases all the old detailed instructions for the treatment of dermatophytosis have been superseded by the advent of griseofulvin, an antibiotic that is remarkably efficient when properly used. In fact, most of its failures may be attributed to the failure of clinicians to employ laboratory means to prove that the disease in question was actually caused by a dermatophyte. Griseofulvin is absolutely useless in other dermatoses, and in fact in some fungous infections of the skin caused by nondermatophyte fungi (Candida albicans, Malassezia furfur). Gentles' discovery in 1958 that the oral administration of an antibiotic

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derived from Pénicillium griseofulvum could cure animals infected by dermatophytes revolutionized the treatment of human infections of the same kind. Seldom has a drug been so rapidly and intensively studied; within a few months it had become firmly established, and its potentialities and some of its limitations were well documented. T h e literature now contains several hundred papers on this subject, only a few of which are listed in the appended bibliography. Before the advent of griseofulvin it was difficult to cure dermatophytosis by topical use of fungicidal chemicals of ever-increasing potency in high dilution because it was mechanically impossible to cause them to penetrate as deeply as the fungi into the infected tissues of the hair follicles and the nails, and even into the thickened keratin of palms and soles. Even when treatment was accompanied by keratolytics, manual epilation, and evulsion of nails, success was often impossible to attain in such areas, whereas cure was easy on glabrous, thin-skinned regions. Wilson (1955), in a paper presented before the International Symposium of Therapy of Fungous Diseases, stated: T h e simplest conceivable way in which complete control of fungous diseases could be achieved would be through the discovery of a perfect fungicide. Such a substance should have many attributes: it should be stable, soluble, colorless, odorless, tasteless, absolutely nontoxic to human beings and free of undesirable side effects and active against all pathogenic fungi wherever they might have invaded in concentrations easily maintained by oral or parenteral administration. Since topical medication of dermatophytosis has such limitations in depth penetration, the ideal treatment would be by such a drug working from within outward, which could endow the cells eventually destined to produce keratin with the power to resist fungi completely, this power persisting as they become keratinized, and the drug exerting its effects from within outward. . . . It seems unlikely that such a goal will soon be reached. Three years later Gentles (1958) wrote: "It is quite remarkable how closely griseofulvin conforms to the requirements laid down by Wilson for the ideal drug for the treatment of the dermatophytoses." Griseofulvin approaches the ideal more closely than most drugs tor their specific purposes. It is stable, colorless, odorless, only mildly bitter in taste, sufficiently soluble, essentially nontoxic to the vast majority of human beings, and free of undesirable side effects to a comforting degree. It is usually absorbed reasonably well after oral ingestion. It is incorporated into the cells of the epidermis in concentrations sufficient to inhibit completely the growth of dermatophyte fungi, although it does not kill them, and this potency is maintained by the cells during the process of their keratinization and thereafter, unless the drug is partly dissolved away from the surface by bathing or by perspiration.

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T o be reliably effective, griseofulvin must be administered in dosages of about 15 mg per kilogram of body weight daily, although about 40 percent of the patients have achieved equal success with half of that amount, and 65 percent, with three-fourths of it. Recently a more finely powdered, micronized form of griseofulvin has been advocated as being equally effective at approximately half the dosage of the old type, and this observation appears to be correct in the majority of cases. It has also been shown that absorption of the drug from the intestinal tract is enhanced if it is ingested with a meal high in fats (Crounse, 1961). These facts become more worthy of consideration when adequate supplies of the drug are difficult to obtain, or when the cost to the patient threatens to become prohibitive. In tinea corporis or tinea cruris, and in many cases of tinea capitis, griseofulvin need be administered for only two to four weeks, preferably on the more reliable maximum dosage schedule. In tinea of the nails, and in the extremely hyperkeratotic tinea of soles and palms caused by T. rubrum, it is necessary to continue the drug for many months, and financial considerations often dictate taking advantage of all methods of reducing the total cost of treatment. Furthermore, some patients cannot tolerate the full daily dosage, but they may reasonably expect success with smaller amounts. It is necessary to mention, however, that the incidence of gastrointestinal intolerance seems to be higher with the micronized form of the drug, even in reduced dosage, and that few persons can tolerate a diet high in fat content continuously for several months. In general, 250 mg of the regular type of griseofulvin three times daily is an adequate dosage for small persons up to 60 kg in weight, four times daily, for those up to 80 kg, and five times daily, for those who are heavier. Half this amount of the micronized type is usually equally efficient. T o avoid intolerance, it is better to divide the daily dosage into portions to be taken after each meal, but as much success has been claimed for the administration of the entire daily dosage at one time. The patient therefore should be instructed that if one dose is forgotten at its regular time, it may be added to the next one in order to maintain the total daily amount. Griseofulvin has proved to be a remarkably nontoxic drug, although of course it is not entirely free of such implications. Gastrointestinal intolerance is the most common, usually nausea, "moldy" eructations, or diarrhea. Headache is occasionally complained of. Skin eruptions varying from morbilliform to urticaria or erythema multiforme have been reported, and occasionally photosensitivity, stomatitis, glossitis, and general malaise have been observed, but it has not always been proved that these ailments were etiologically related to the drug. The fear, expressed in the early days of griseofulvin, that it could be dangerously depressing to the leucocytes or the hematopoietic system has

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been entirely dispelled by close observation of many patients; in fact, it has become customary not to ask patients to have blood counts taken. The drug does not interfere with human spermatogenesis (MacLeod and Nelson, i960). Rumors of a few cases of coronary occlusive death occurring during griseofulvin administration exemplify the need for reasonable proof of toxicity before condemning a drug. That these deaths were purely coincidental is suggested by Rubin (1963), who reports that griseofulvin actually increases blood flow in the coronary region as well as in the extremities, and by de Pasquale et al. (1963), who claim that it reduced the number of attacks of angina pectoris in ten patients. Griseofulvin has been administered without observable harm and without decreased efficiency to patients whose fungal infection was accompanied by one or another of a group of serious diseases, including scleroderma, lupus erythematosus, various lymphblastomas, diabetes, and tuberculosis. Steagall (1963) reports a severe reaction to griseofulvin in a woman with lupus erythematosus under treatment with steroids, and Redeker, Sterling, and Bronow (1964) describe precipitation of acute porphyria in a susceptible patient, since confirmed by others.

Griseofulvin in different types of infection Tinea capitis.—All types of tinea capitis usually respond to treatment with griseofulvin alone. Cultural identification of the causative organism serves to warn against cessation of the dosage too soon in the more resistant patients. So also does clinical and mycologic examination at regular intervals, using dark light and direct microscopic examination of hairs from involved areas during the course of the treatment, and cultures in the terminal stages. The dosage should be continued until all evidence so acquired is negative. Small children need a higher dosage of griseofulvin per kilogram than adults. They should seldom be given less than 500 mg daily (250 mg of the micronized type), but children weighing more than forty kilograms should receive an adult dosage. Several well-controlled studies have shown that a single large dose of griseofulvin, 5 to 7 grams, given on one day only, has cured a large proportion of patients with the common childhood tinea capitis caused by Microsporum, but not those whose infection was caused by Trichophyton tonsurans or T. violaceum. The failure rate, however, is still too high to be ideal, and the regimen is recommended only for patients who come from a distance or have transportation difficulties and thus cannot easily be brought back to their clinics for subsequent treatment. The large, single dose may also be used if the clinician suspects that the regular dosage schedule is not being followed because of inadequate family supervision, for he can thus observe ingestion of the entire dose and keep the patient

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long enough to be certain that it is not vomited. There is evidently no danger of severe toxicity with this dosage. In some instances, where supplies of the drug are extremely small in comparison with the number of cases, the single-dose regimen is used on all patients at the first visit, and later additional doses are given to those who are not cured by it. Although the part of the hair infected by the fungi grows out of the follicle enough to clear the scalp in about two weeks, the infected tip may still be able to cause reinfection after the drug is discontinued. Whenever possible, close clipping of scalp hair at that time is a useful preventive measure. In occasional cases griseofulvin, for some unknown reason does not effect a cure or is not tolerated by the patient. It is well to remember that the drug is not fungicidal, but only fungistatic, and that it is really the epidermal effluvial current that finally forces the fungi away from the follicles sufficiently to be shed, and thus to effect the cure. The older methods of treatment by topical use of antifungal ointments during protracted periods, frequent shampoos, and clipping of the hair often also effect a cure. Temporary complete depilation of the scalp by X-radiation, or by systemic administration of thallium acetate for resistant cases, has apparently been entirely abandoned, although a fatty ester compound, applied locally, is being used in Russia for epilation. Tinea corporis.—This form of the disease, except for the chronic varieties caused by T. rubrurn or T. concentricum, responds well and quickly to griseofulvin, usually clearing within two or three weeks. When only a few small spots are present, locally applied fungicides may be effective just as rapidly. Sulfur and salicylic acid, 3 percent of each, in ointment or cream, or any one of numerous proprietary topical fungicides, may thus save the patient expense. Tinea barbae.—Although somewhat resistant to griseofulvin, tinea barbae does yield to persistent use of the drug in maximal dosage. Excellent results are usually obtained. Tinea cruris.—This form is easily and quickly controlled by oral griseofulvin; the treatment is a welcome change from the older methods of using topical fungicides, which frequently were not well tolerated by delicate genital or anal surfaces. It is usually necessary only to soothe the areas locally with mild treatment appropriate for whatever dermatitis is present, while relying on oral griseofulvin to combat the fungus. This method is reliable only if the infection has been caused by a dermatophyte and not by Candida albicans, for disease caused by the latter is never helped, and is indeed often worsened, by griseofulvin. Before relying on the oral griseofulvin regime, it is mandatory to examine bits of tissue microscopically to see that the characteristic hyphae of a dermatophyte fungus are present and, even more important, that the characteristic budding spores of Candida albicans infection are absent.

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Tinea pedum and manuum.—Tinea of the feet and hands responds erratically to griseofulvin, and success depends largely on good diagnostic control in the selection of therapy. The acute, vesicular type that appears so suddenly on toe webs during hot weather, especially when occlusive shoes are worn by persons whose feet perspire freely, requires much more than a prescription for griseofulvin. In more than half of these cases no dermatophyte at all is involved; in others it is partly responsible, but almost never can it be blamed entirely. Better foot hygiene and the use of measures to reduce the effects of perspiration are very helpful. Cotton socks distribute perspiration by their capillary wicklike action and draw it upward, so that it evaporates outside the shoe. Nylon fibres do not become wet and hence produce no capillary action, and silk and wool are less efficient than cotton. Liberal amounts of plain USP talc (without medication, pigment, or perfume, and without starch, which when moist may serve as food for fungi and bacteria), used with well-powdered cotton pledgets to separate the toes and promote aeration, and aerated shoes or sandals are necessary for times of the day when the feet cannot be kept open to the air. In mild cases, this treatment may suffice, with cure resulting in a few days. For more severe cases, soaking in 1:2,000 potassium permanganate solution, or in the less colorful alibour solution (copper sulfate 1:6,000 and zinc sulfate 1:2,000), is the next step. If bacterial infection is also present, an appropriate antibacterial antibiotic in a vanishingcream base is indicated, and, in severe cases, similar systemic therapy. This entire regimen should be inaugurated before griseofulvin is considered, even if dermatophytes are partly responsible, for the condition tends to subside so quickly under proper therapy that griseofulvin does not have time to compete. In the meantime, microscopic examination will reveal dermatophyte infection, if present, and rule out Candida infection (as described above under tinea cruris); cultures have probably had a few days to reveal a dermatophyte before griseofulvin need be added, if response is too slow. The usual dosage is adequate. In its chronic, hyperkeratotic, fissured form, tinea of the feet and hands may be helped more by griseofulvin than by any of the older treatments, although not all cases can be completely cured. This type is usually caused by T. rubrum, and individuals chronically infected almost certainly possess an immunologic defect that renders them hypersusceptible (see section on immunology, above), or some other factor makes their skin particularly attractive to this fungus. It is wise to initiate a search for any such factor by employing blood counts and urinalyses, and by obtaining a history of possible drug therapy, perhaps with corticosteroids or antimetabolites. Before prescribing griseofulvin, the clinician should establish the infection as being caused by T. rubrum, both by direct microscopic discovery of typical hyphae and by recovering the organism in culture. The early administration of the drug may make it impossible later to prove whether

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or not the fungus was ever present, and several weeks may elapse before there is sufficient improvement to indicate whether or not the original diagnostic opinion of fungus etiology was indeed accurate. There is seldom any need for hurry in beginning the drug for a chronic disease, and the patient usually welcomes the plan to precede the use of griseofulvin by diagnostic laboratory studies. Most patients with T. rubrum infection are helped by griseofulvin, and in many the infection is cleared completely (disregarding nail involvement for the moment). In areas other than soles and palms, improvement is often noted within two or three weeks, reducing pruritus and encouraging continuation of the treatment. From two to four months are often needed to bring hyperkeratotic soles and palms back to normal, and in some patients this result is never completely achieved. The feet must be bathed, of course, but excessive soaking in water (as in perspiration) probably leaches out some of the griseofulvin from the outermost layers and thus allows the fungus to continue to live there. The clearing process in these areas is often hastened by local application of keratolytics or topical antifungal preparations, such as Whitfield's ointment or Asterol® in ointment or tincture form. If there seems to be no further improvement, a reassessment by microscopic examination of scrapings is required. If the results are still typically positive, the dosage of griseofulvin should be increased. If they are negative, possibly another associated nonfungal cause of hyperkeratosis, such as psoriasis or Haxthausen's climacteric type, is present. It is sometimes wrong to rely on griseofulvin alone. If complete clearing occurs, and the KOH specimens are negative for fungi, the drug may be discontinued, at least for a probationary period. Some patients remain well, but usually the disease recurs within a few weeks or months, for griseofulvin does not kill the fungi, but merely inhibits their penetration into the depths of the skin. The patient's immunological status is not changed in the slightest degree by the drug, and unless a logical cause of his illness is discovered and cured or controlled, he will again be just as susceptible as before, once the griseofulvin has entirely left the body by the epidermal effluvial current. The environment of such a patient has been hopelessly seeded with skin scales containing potentially living fungal elements, and it is virtually certain that the fungus will have another chance to infect him, especially if involved nails, which probably shed viable fungi continuously, are still present. Fortunately, griseofulvin is so well tolerated that it can safely be used repeatedly by most patients at whatever intervals seem to be indicated. After one or two attempts to obtain complete clearing, many such patients welcome the help griseofulvin affords them as a long-term controlling factor, and they may need to continue such dosage intermittently for life. Some patients have found that, if they watch closely for signs of early

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recurrence, a topical fungicide can clear the infection before it gets too deeply embedded to need griseofulvin. An application of tincture of Asterol® once weekly has controlled the disease in some patients for months or years, and an alcoholic solution of 5 percent salicylic acid has done the same for others. Tinea of the nails.—This form of tinea is the least responsive of all dermatophyte infections to griseofulvin, partly because the original diagnosis was undoubtedly inaccurate. It is impossible to differentiate fungal nail involvement accurately from other conditions, notably psoriasis, without the aid of careful laboratory studies. Nothing is more foolish than to start a patient on a course necessitating the oral use of four or more expensive tablets daily for at least six months, and often for a year or more, without diligently searching for evidence that he has at least a fighting chance of success. Yet every dermatologist encounters many patients who have been so treated. We have never yet found a patient who was not willing to spend the first two to six weeks, if necessary, in submitting to microscopic and cultural studies to ascertain the true diagnosis, and we do not begin griseofulvin until we have successfully established a dermatophyte as the cause. Often the fungus can be discovered on the patient's first visit, if the infected nail is clipped away as far as possible and several specimens of the sawdust-like detritus are obtained from the deepest areas, for immediate microscopic examination after heating with 15 percent K O H solution. A t the same time other specimens are obtained for implantation into several culture bottles. (The chances for success are increased if multiple inoculations are made on the first day, preferably taken from different nails). If the immediate microscopic examination reveals typical dermatophyte hyphae in the usual profusion, the fungal origin of the disease is established. T h e one possible pitfall is that not infrequently nonpathogenic fungi are encountered as secondary invaders in the nail detritus, particularly if the material is taken too far distally from the actively progressing area of the disease. T h e hyphae of these contaminants are usually entirely different in appearance from dermatophytes, being larger and thicker-walled, and failing to break up into the short segments called arthrospores, as dermatophytes do. Sometimes the contaminant hyphae are also tinted brownish. Even so, cultures still serve to confirm the diagnosis, and are helpful in prognosis, for the recovery of T. rubrum signifies a probable immunologically defective person more likely to prove resistant to treatment. It often happens that only one or two toenails are involved in a proved fungous infection, and that no other skin areas are infected. If informed of all of the implications, the patient may decide, with justification, not to take griseofulvin for months or years to obtain a cure. He may prefer to neglect the infection unless it spreads to other nails (particularly to fingernails), or causes other skin infection. He should be given this choice, for there

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are no serious sequelae of neglecting the affected nails, and the patient may change his mind if future developments indicate a different course. Nail infection should be treated with the full dosage of griseofulvin for several weeks at least, until there is some indication of improvement. The involved part of the nail should be farther distally from the nail root than before, and the proximal, newly formed part should appear healthy. If all infected nails show these encouraging signs, it is permissible to reduce the dosage by half during an observation period of a few weeks. If the outward growth of improved nails continues, the reduced dosage may be continued; if progress is delayed or stops, the full dosage should be resumed. Some patients do not begin to show improvement until the ordinary dose has been doubled for some weeks. As noted above, the drug does not kill the fungi but only prevents their proximal growth; it is the epidermal effluvial current that finally causes the infected parts of the nail to grow far enough distally to be clipped away completely. Therefore the rate of nail growth determines the time necessary for cure, and it varies widely from patient to patient, as well as among the nails of a single patient. Circulatory stasis is an important factor in some instances, as the nails of a patient whose legs are afflicted with varicosities often grow more slowly than when the limbs are normal. Toenails usually grow more slowly than fingernails. Desai (i960), among others, believes that at times dermatophyte fungi actually slow or stop nail growth. Other factors as yet unknown may explain the frequent observation that some nails clear quickly while others on the same patient show slower progress or none at all. Frequent debridement of all removable infective material may be of assistance by reducing the amount of parent stock of the fungus which contributes to the energy of the proximally penetrating hyphae. Complete removal of stubborn nails by evulsion is often successful, but failures are common as well. As noted above, patients infected with T. rubrum are immunologically hypersusceptible, and are almost certain to become reinfected. They are therefore unlikely to welcome many episodes of nail evulsion, but will choose control rather than cure. Topical therapy with antifungal drugs probably does not add to the chance of success, although some substances are still strongly favored for such a role.

Bibliography Adamson, H. G. 1895. Observations on the parasites of ringworm. Brit. J. Dermatol., 7:201. Ainsworth, G. C., and P. K. C. Austwick. 1955. Survey of animal mycoses in Britain. Vet. Record, 67:88. Ajello, L. 1953. The dermatophyte Microsporum gypseum as a saprophyte and parasite. J. Invest. Dermatol., 21:157-171.

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247

Ajello, L., G. Brumfield, and J . Palmer. 1963. Non-fluorescent Microsporum audouinii infections. Arch. Dermatol., 87:605. Ajello, L., and M. E. Getz. 1954. Recovery of dermatophytes from shoes and shower stalls. J . Invest. Dermatol., 22:17-21. Area Leao, A. £., and M. Goto. 1950. O tokelau entre los indios do Brasil. Hospital (Rio), 37:225. Atkinson, R. M., C. Bedford, K. J . Child, and E. G. Tomich. 1962. Effect of particle size on blood griseofulvin levels in man. Nature (London), 193:588. Baer, R. L., S. A. Rosenthal, and Domenica Furnari. 1955. Survival of dermatophytes applied to the feet. J . Invest. Dermatol., 24:619-622. Barlow, A. J . E., F. W. Chattaway, R. V. Brunt, and J . D. Townsley. 1961. A study of the susceptibility to infection by Trichophyton rubrum. J . Invest. Dermatol., 37:461. Blank, F. 1955. Dermatophytes of animal origin transmissible to man. Amer. J. Med. Sci., 229:302. Blank, F., and G. E. Craig. 1954. Family epidemics of ringworm contracted from cattle. Canad. Med. Assoc. J., 71:234. Blank, H., ed. i960. Symposium on griseofulvin. Arch. Dermatol., 81:649. Blank, H. 1963. The place of griseofulvin in dermatologic therapy. Proc. 12th. Intern. Congr. Dermatol. 11:1391. Amsterdam: Excerpta Medica Foundation. Blank, H„ F. J . Roth, Jr., W. W. Bruce, M. F. Engel, J . G. Smith, Jr., and N. Zaias. 1959. The treatment of dermatomycoses with orally administered griseofulvin. Arch. Dermatol., 79:259. Blank, H., and J . G. Smith, Jr. i960. Widespread Trichophyton rubrum granulomas treated with griseofulvin. Arch. Dermatol., 81:779. Bonk, A. F., L. Friedman, and V. J . Derbes. 1962. Experimental dermatophytosis. J . Invest., Dermatol., 39:281. Burgoon, C. F., J . H. Graham, R. J . Keiper, F. Urbach, J . S. Burgoon, and E. B. Helwig. i960. Histopathologic evaluation of griseofulvin in Microsporum audouinii infections. Arch. Dermatol. 81:724. Carri6n, A. L., and M. Silva. 1944. Ringworm of the scalp in Puerto Rico. Puerto Rico J . Public Health Trop. Med., 19:329. Castellani, A. 1934. Tinea imbricata (tokelau). J . Trop. Med. Hyg., 37:363. Chick, E. W., and D. S. Behar. 1961. A simple fluorescent method for the detection of superficial fungi in skin and hair, using acridine orange and KOH. J . Invest. Dermatol., 37:103. Crounse, R. G. 1961. Human pharmacology of griseofulvin: the effect of fat intake on gastrointestinal absorption. J . Invest. Dermatol., 37:529. . 1963. Effective use of griseofulvin. Arch. Dermatol., 87:176. Davidson, A. M., P. H. Gregory, and A. R. Birt. 1934. Clinical and mycologic study of suppurative ringworm. Canad. Med Assoc. J., 31:587. Dawson, C. O., and J . C. Gentles. 1961. The perfect stages of Keratinomyces ajelloi Vanbreuseghem, Trichophyton terrestre Durie and Frey, and Microsporum nanum Fuentes. Sabouraudia, 1:49-57. Degos, R. i960. Griseofulvin treatment at Saint Louis Hospital, Paris (favus, 28 cases). Arch. Dermatol., 81:806. De Pasquale, N. P., J . W. Burks, and G. E. Burch. 1963. Treatment of angina pectoris with griseofulvin. J . Amer. Med. Assoc., 184:421.

248

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Desai, S. C. i960. Effect of griseofulvin on Trichophyton rubrum and T. violaceum infections. Arch. Dermatol., 81:849. Desai, S. C., J . M. Prabhakar, and M. A. Bhat. 1962. Dysproteinemia in chronic dermatomycosis due to Trichophyton rubrum with negative anergy to trichophytin. J . Invest. Dermatol., 39:365. Dostrovsky, A., G. Kallner, F. Raubitschek, and F. Sagher. 1955. Tinea capitis: an epidemiologic, therapeutic and laboratory investigation of 6,390 cases. J . Invest. Dermatol., 24:195. Emmons, C. W. 1934. Dermatophytes: natural grouping based on the form of the spores and accessory organs. Arch. Dermatol. Syphil., 30:337-362. Fernández, M. D., and M. D. Jao. 1962. Tinea imbricata successfully treated with griseofulvin. Arch. Dermatol., 86:65. Fischer, J . B., and N. M. Wrong. 1952. Fungous infection of skin, hair and nails. Canad. Med. Assoc. J., 67-398. Fishman, I. M. 1953. Epidemic favus of glabrous skin. Arch. Dermatol. Syphil., 68:38. Fowle, L. P., a n d ' L . K. Georg. 1947. Suppurative ringworm contracted from cattle. Arch. Dermatol. Syphil., 56:780. Friedman, L., and V. J . Derbes. i960. T h e question of immunity in ringworm infections. Ann. N.Y. Acad. Sci., 89:178. Friedman, L., V. J . Derbes, and M. T . Hodges. 1964. The course of untreated tinea capitis in Negro children. J . Invest. Dermatol., 42:237. Friedman, L., V. J . Derbes, and T . A. Tronovich. i960. Single dose therapy of tinea capitis. Arch. Dermatol., 82:415. Fuentes, C. A., and R . Aboulafia. 1955. T. mentagrophytes from apparently healthy guinea pigs. Arch. Dermatol. Syphil., 71:478. Gentles, J . C. 1958. Experimental ringworm in guinea pigs: oral treatment with griseofulvin. Nature (London), 182:476. . i960. Report on animal experiments with griseofulvin. Arch. Dermatol., 81:703. Gentles, J . C., M. J . Barnes, and K. H. Fantes. 1959. Presence of griseofulvin in hair of guinea pigs after oral administration. Nature (London), 183:256. Georg, L. K. 1954. T h e relationship between the downy and granular forms of trichophyton mentagrophytes. J . Invest. Dermatol., 2 3 : 1 2 3 - 1 4 1 . . 1956. Role of animals as vectors of human fungus disease. Trans. N.Y. Acad. Sci., 2d ser., 18:639. . 1957. Dermatophytes: new methods in classification. Atlanta: U.S. Public Health Service. . i960. Epidemiology of the dermatophytoses: sources of infection, modes of transmission and epidemicity. Ann. N.Y. Acad. Sci., 89:69. Georg, L. K., P. Doupagne, S. R . Pattyn, and H. Neves. 1963. Trichophyton yaoundei, a dermatophyte indigenous to Africa. J . Invest. Dermatol., 41:19. Goldfarb, N. J., and M. B. Sulzberger. 1960. Experiences in 137 patients treated with oral griseofulvin. Arch. Dermatol., 81:859. González-Ochoa, A., and M. Ahumada-Padilla, i960. New schemes in the treatment of dermatophytosis with griseofulvin. Arch. Dermatol., 81:833. González-Ochoa, A., E. Ricoy, and M. A. Bravo-Becherelle. 1964. Study of prophylactic action of griseofulvin in human experimental infection with Trichophyton concentricum. J . Invest. Dermatol., 42:55.

Dermatophytosis

249

Gonzilez-Ochoa, A., and B. Romo Vasquez. 1945. Dermatofitos causantes de tina de la piel cabelluda en la ciudad de Mexico. Rev. Inst. Salubr. Enferm. Trop., 6:145. Gordon, M. A . 1953. T h e occurrence of the dermatophyte, Microsporum gypseum, as a saprophyte in soil. J. Invest. Dermatol., 20:201-206. Graham, J. H., W . C. Johnson, and C. F. Burgoon. 1964. Tinea capitis. Arch. Dermatol., 89:528. Halde, C. 1964. T i n e a imbricata. Pers. comm. to authors; to be published. Harrell, E. R „ F. C. Bocobo, F. Kingery, and L. Miedler. i960. Effect of griseofulvin on tinea capitis caused by Microsporum audouinii. Arch. Dermatol., 81:797. Haxthausen, H. 1942. T h e pathogenesis of allergic eczema elucidated by transplantation experiments on identical twins. Acta Dermato-venereol., 23:438. Ho, K., and G. Tsujinaka. 1961. Histopathological and histochemical observations of dermatophytid. Bull. Pharm. Research Inst. (Takatsuki), 33(July):g. Howell, J. B., J. W. Wilson, and M. A. Caro. 1952. T i n e a capitis caused by Trichophyton tonsurans. Arch. Dermatol. Syphil., 65:194. Jacobs, P. H., H. C. Taylor, III, and J. C. Shafer. 1964. Studies of fungi at Amundsen-Scott I.G.Y. South Pole base. Arch. Dermatol., 89:117. Jillson, O. F., and W. R. Buckley. 1952. Fungous disease in man contracted from horses and cattle. New Engl. J. Med., 246:996. Kaminsky, A. i960. Comparative effects of griseofulvin on onychomycosis and psoriasis unguium. Arch. Dermatol., 81:839. Kligman, A . M. 1952. T h e pathogenesis of tinea capitis due to Microsporum audouinii and Microsporum canis. I. Gross observations following the inoculations of humans. J. Invest. Dermatol., 18:231. . 1955. Pathogenesis of tinea capitis. II. Dynamics of host-parasite relationship. Arch. Dermatol. Syphil., 71:313. Kligman, A . M., and D. Ginsberg. 1950. Immunity of the adult scalp to infections with Microsporum audouinii. J. Invest. Dermatol., 14:345. Kligman, A. M., and M. Gray. 1952. Trichophyton rubrum infection. Arch. Dermatol. Syphil., 66:662-663. Lazar, P., and H. Rattner. i960. Griseofulvin therapy for superficial fungous infections: effect upon concurrent diseases. Arch. Dermatol., 81:863. Levine, H. B., H. S. Alden, and L. Ajello. i960. Use of griseofulvin in office practice. Arch. Dermatol., 81:827. Lewis, G. M., et al. 1944. Measures to prevent and control epidemic ringworm of the scalp. N.Y. J. Med., 44:1327. Lewis, G. M., and M. E. Hopper. 1936. Ringworm of the scalp. III. Clinical and experimental studies. Arch. Dermatol. Syphil., 35:460. . 1937. Comparative reactions to cutaneous tests with trichophyton in children with and without ringworm of the scalp. Arch. Dermatol. Syphil., 36:821. Lewis, G. M., M. E. Hopper, and M. J. Scott. 1953. Generalized Trichophyton rubrum infection associated with systemic lymphoblastoma. Arch. Dermatol. Syphil., 67:247. Livingood, C. S., and D. M. Pillsbury. 1941. Ringworm of the scalp: cultural and immunologic studies in 130 cases. J. Invest. Dermatol., 4:43. Lorincz, A. L „ J. O. Priestley, and P. H. Jacobs. 1958. Evidence for a humoral

250

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mechanism which prevents growth of dermatophytes. J . Invest. Dermatol.,

3 ,:i 5Luscombe, H. A., and O. Bingul. 1964. Nodular granulomatous perifolliculitis caused by Microsporum gypseum. Arch. Dermatol., 89:274. MacLeod, J., and W. O. Nelson, i960. Griseofulvin and human spermatogenesis. Arch. Dermatol., 81:758. McNall, E. G., T . H. Sternberg, V. D. Newcomer, and L. J . Sorensen. 1961. Chemical and immunological studies on dermatophyte cell wall polysaccharides. J . Invest. Dermatol., 36:155. Manson, P. 1892. On a case of tinea imbricata. Brit. J . Dermatol., 4:5. Many, H., V. J . Derbes, and L. Friedman, i960. Trichophyton rubrum: exposure and infection within household groups. Arch. Dermatol., 82:226. Montagna, W. 1962. The structure and function of the skin. 2d ed. New York: Academic Press. Murrell, T . W., and J . D. Reid. 1953. Inflammatory ringworm in man due to Trichophyton faviforme contracted from cattle. Virginia Med. Monthly, 80:572-575. Noe, O., M. Jacobs, and H. H. Berman. 1961. Griseofulvin in the treatment of tinea violaceum of the scalp. Arch Dermatol., 84:645. Nunez Andrade, R . 1953. Tinea imbricata. [In Spanish.] Medicina (Mexico), 33:47BPardo-Castelld, V. i960. The treatment of dermatomycosis with griseofulvin. Arch. Dermatol., 81:772. Pipkin, J . L. i960. The treatment of endothrix Trichophyton infections with griseofulvin. Arch. Dermatol., 81: 813. Polunin, I. 1952. Tinea imbricata in Malaya. Brit. J . Dermatol., 64:378. Redeker, A. G., R. E. Sterling, and R . S. Bronow. 1964. Effect of griseofulvin in acute intermittent porphyria. J . Amer. Med. Assoc., 188:466. Riehl, G. 1959. Griseofulvin: ein peroral Wirkendes Antimykoticum. Hautarzt, 10:136. Robinson, H. M., Jr., and W. R . Dunseath. 1962. Micronized griseofulvin. J . Invest. Dermatol., 39:65. Rosenthal, S. A., and R. Van Breuseghem. 1962. Viability of dermatophytes in epilated hairs. Arch. Dermatol., 85:103. Rosenthal, S. A., and R. S. Wise. i960. Studies concerning the development of resistance to griseofulvin by dermatophytes. Arch. Dermatol., 81:684. Rothman, S., B. S. Smiljanic, A. L. Shapiro, and A. W. Weitkamp. 1947. Spontaneous cure of tinea capitis in puberty. J . Invest. Dermatol., 8:81. Rubin, A. A. 1963. Coronary vascular effects of griseofulvin. J . Amer. Med Assoc., 185:971. Salazar Leite, A., J . Bastos Daluz, and M. Viana de Meira. 1947. Ringworm among the Negroes of Angola. Acta Dermato-sifil. (Madrid), 38:1173. Sams, W. M. i960. Favus treated with griseofulvin. Arch. Dermatol., 81:803. Steagall, R . W., Jr. 1963. Severe reaction to griseofulvin. Arch. Dermatol., 88:218. Stockdale, P. M. 1961. Nannizzia incurvata gen. nov., sp. nov.: a perfect state of Microsporum grpseum. Sabouraudia, 1:41-48. Sulzberger, M. B., and R . L. Baer. 1959. Griseofulvin: an oral antibiotic for the treatment of many common fungous infections of the skin, hair and nails. Excerpta Med. X I I I , 13:145.

Dermatophytosis

251

Swartz, J. H., and B. E. Lamkins. 1964. A rapid simple stain for fungi in skin, nail scrapings and hairs. Arch. Dermatol., 89:89. Taplin, D., and H. Blank. 1961. Microscopic morphology of Trichophyton rubrum. J. Invest. Dermatol., 37:523. Van Breuseghem, R. 1950. Study of 136 strains of Trichophyton ferrugineum (Ota 1921) Langeron and Milochevich 1930 and of its white variety, isolated in the Belgian Congo. [In French.] Ann. Parasitol. Hum. Comp., 25:485-492. Vilanova, X., and M. Casanovas, i960. Griseofulvin in the treatment of dermatophytosis. [In Spanish.] Acta Dermato-sifil. (Madrid), 51:43. Walzer, R. A., and J. Einbinden 1962. Immuno-fluorescent studies in dermatophyte infection. J. Invest. Dermatol., 39:165. Weiner, M. A., J. Q. Gant, Jr., and A. H. Gould. 1961. Clinical evaluation of griseofulvin in 327 patients. Med. Ann. D.C., 3o(Jan.):i. Williams, D. I. i960. Griseofulvin and Trichophyton rubrum infections. Arch. Dermatol., 81:769. Williams, D. I., R. H. Marten, and I. Sarkany. 1958. Oral treatment of ringworm with griseofulvin. Lancet, 2:1212. Wilson, J. W. 1955. Possible approaches to the therapy of fungous diseases. In T . H. Sternberg and V. D. Newcomer, eds., Therapy of fungus diseases: an international symposium. Boston and Toronto: Little, Brown. . 1959. Some observations on fungous diseases in 1959. [In English and Spanish.] Med. Clin. North Amer., 43:857. Wilson, J. W., H. Levitt, and O. A. Plunkett. 1952. Asterol dihydrochloride® in the treatment of dermatophytosis due to Trichophyton rubrum. J. Invest. Dermatol., 19:319. Wilson, J. W., and O. A. Plunkett. 1951. Lack of fluorescence of scalp hairs infected with Microsporum gypseum. J. Invest. Dermatol., 16:119. Wilson, J. W., O. A. Plunkett, and A. Gregersen. 1954. Nodular granulomatous perifolliculitis due to T. rubrum. Arch. Dermatol. Syphil., 69:258. Wrong, N. M. 1961. Critical appraisal of griseofulvin in dermatology. Canad. Med. Assoc. J., 85:1019. Zakon, S. J., and T . Benedek. 1944. David Gruby and the centenary of medical mycology, 1841-1941. Bull. Hist. Med., 16:155.

*9 Tinea versicolor

INTRODUCTION is a common, extremely superficial infection of the skin caused by a single species of fungus, Malassezia furfur. Among other names given to the disorder are some of descriptive nature, such as achromia parasitica (Jeanselme), achromia parasitaria (Pardo-Castellô), pityriasis versicolor tropica, tinea flava, dermatomycosis furfuracea, kleinflechte, and chromophytosis; in some areas of the world colloquial terms, such as "hody potsy," are used.

T I N E A VERSICOLOR

HISTORY Very early in the history of medical mycology, Eickstedt (in 1846) and Sluyter (in 1847) discovered tinea versicolor. Robin studied the disease extensively in 1853, but, interpreting the sporulation incorrectly, named the fungus Microsporum furfur, believing it to be related to M. audouinii. Bâillon corrected this mistake in 1889 and created the generic name Malassezia, retaining the species epithet furfur; this combination was uni-

252

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Tinea versicolor

versally accepted until Gordon (1951) called attention to the close relationship of the fungus to the genus Pityrosporum, to which the generic name may need to be changed. ETIOLOGY Probably all human beings are at some time or other contacted by spores of M. furfur, without the slightest evidence to indicate that the fungus is responsible for causing any disease. It is therefore an opportunistic fungus, needing either special localized or systemic factors capable of causing less than normal resistance; examples of both are well established. DISTRIBUTION T i n e a versicolor is worldwide in distribution, but occurs much more frequently in tropical and humid climates than in others, undoubtedly because its opportunities are enhanced by excessive perspiration. In some coastal areas of Mexico (Gonzalez-Ochoa, 1956), and in western Samoa (Marples, 1950), the incidence is as high as 50 percent in the general population. N o age is exempt, but young adults are most commonly afflicted. Race or color of skin probably does not significantly affect susceptibility, but more cases are seen in darker-skinned persons because its objectionable appearance is more noticeable in them and because more of them live in tropical climates. EPIDEMIOLOGY Acquisition of the infection depends almost entirely on abnormalities in the patient, rather than on contact of the fungus with the skin. Apparently the organism has no habitat in nature except skin, and probably only human skin. It has never been reported from animals, and experimental inoculations have not been successful. CLINICAL

CHARACTERISTICS

In 1947 Darier stated that the incubation time for tinea versicolor is one month. It begins as multiple tiny, macular, scaly spots, usually on the trunk and more often anteriorly, which quickly enlarge and may coalesce to form gyrate areas of scaling. T h e r e is rarely any evidence of inflammation, and pruritus is almost never complained of unless a chemical has caused irritation. T h e attention of the patient is almost invariably attracted because of the unsightly mottled appearance of the infected region. T h e contrast between involved patches and normal skin is heightened by the depth of natural skin color or by the tanning caused by sun expo-

254

The superficial mycoses

sure. Several mechanical factors seem to take part in this process. T h e fungus causes alteration in the dry, keratinized surface of the skin which may result either in increasing its fragility or, less frequently, in making it more adherent. T h e fungal elements are present in such profusion that they may actually constitute a larger total mass than the epidermal cells, resulting in a thickening of the keratin layer, and consequently in a slight elevation of the affected spots above the surface of the normal skin. Because melanin is contained in the cells of all layers of the epidermis, anything that causes a thinning of any of its layers also lightens its color; this change usually occurs in tinea versicolor because the scales are loosened and then lost by shedding. T h e fungus also appears to be able to shield the areas from the tanning effect of sunlight, causing a further lightening of the color when compared with the color of normal, tanned skin. Usually, then, patches of the infection are lighter in color than the normal skin. In some patients, and in some areas of individuals who are afflicted as described above, the reverse may happen; the fungus seems to cause additional tenacity of the keratin layer, and the affected spots become slightly raised and thicker than the normal skin. T h e retention of an additional thickness of melanin-containing keratinized cells darkens the color of the involved areas, and the disease presents spots or areas of hyperpigmentation instead of the usual hypopigmentation. In very light-skinned persons, who are not at all exposed to the sun, the hyperkeratosis may cause the infected areas to be covered with snow-white scales. In some patients only the sternal region may be affected, but more extensive spread is the rule. All parts of the body may be diseased except palms and soles. In some individuals the disease favors the intertriginous areas. Mucous membranes, hair, or nails are never involved. PATHOLOGY As tinea versicolor is superficial, and rarely causes inflammatory change, little need be said here about pathology. It is interesting to observe, in sections of biopsy material stained by special fungal methods, the tremendous numbers of the organisms limited to the keratin layer; sometimes they seem almost to have replaced the cells of that layer. They are large, and are easily diffentiated from any other structures, even from •dermatophytes, by the initiated eye. DIFFERENTIAL

DIAGNOSIS

T h e principal disorder that may be confused with tinea versicolor is vitiligo, but it seldom presents a real problem. In vitiligo the lesions are absolutely devoid of melanin pigment, instead of being simply hypochromic; there is no scaling; and the borders are usually hyperpigmented in con-

Tinea versicolor

255

trast with the normal skin. In seborrheic dermatitis, yellowish, greasy scales develop, and are usually accompanied by considerable inflammation and pruritis, features that are absent in tinea versicolor. Pinta, not predominantly a scaly disorder, occasions a variety of pigmentary changes, causes some induration underneath the lesions, and induces a positive reaction to serologic tests for syphilis. Tinea versicolor has none of the inflammatory characteristics of dermatophytosis, pityriasis rosea, secondary syphilis, or the exanthemata. T h e disease called pityriasis alba may seem to be identical with tinea versicolor, but the fungi so easily demonstrated in scrapings from the latter are absent. Chloasma is not a scaly disorder. The lesions of tinea versicolor fluoresce distinctively under filtered ultraviolet radiation, producing a color varying from yellow with a bluish tinge to brown, depending on the depth of pigment. Sometimes dark light reveals tinea versicolor when it is not clinically apparent in direct light. Keddie (1963) has reported the value of using transparent adhesive tape (pressure-sensitive tape, Scotch tape®), for when removed it brings with it the scales, which are loaded with the fungus. Placing the tape on a microscopic slide makes examination easy. The preparation may be stained with gentian violet to advantage, if desired. MYCOLOGY Malassezia furfur (Robin) Baillon 1889 is fortunately very easy to recognize in its pathological location in skin scales, but its culture is too difficult to be routinely useful in diagnosis. In direct mounts prepared with KOH, it exhibits two types of elements: short, stubby, curved, abortive hyphae, never seen to be connected in chains, each segment about 3 to 4 microns in diameter by 8 to 12 in length; and blastospores (budding cells), consisting of clusters of spheroidal cells 4 to 6 microns in diameter. The latter are sufficiently larger than the blastospores of Candida albicans for easy differentiation, and C. albicans produces longer, true hyphal strands. These characteristics are sometimes serviceable in examination of material taken from intertriginous areas, where either fungus might be present. Malassezia furfur often grows so profusely in the infected spots that the microscopic appearance of specimens prepared with K O H appears to be almost that of a pure culture, and occasionally an inexperienced observer fails to make the diagnosis because of accepting the organisms as the skin cells ordinarily expected in such smears (which they do not, of course, resemble even remotely). Only if the infection is very mild, or is in an early stage of development, or if the patient has been using a fungicide, is there difficulty in finding enough fungal cells to be conclusively diagnostic. The close relationship between M. furfur and the fungus named Pityrosporum orbiculare, noted above, suggests that the two fungi will eventually be shown to be identical. Recent reports by Gordon (1951), Keddie

The superficial mycoses

Fig. 14. Malassezia furfur (Pityrosporum orbiculare?), causative organism of tinea versicolor. Upper left: as seen in Scotch tape strip from skin (PAS x 850). Upper right: as seen in histopathologic section; organisms in mouth of follicle (PAS x 140). Middle left: cluster of conidia produced by elongated conidiophore (PAS x 2,000). Lower left: culture mount (PAS x 2,000). Lower right: blastospores in culture mount (PAS x 4,000).

Tinea versicolor

257

(1963), Sternberg and Keddie (1961), Keddie et al. 1963), and Burke (1961) are still considered by these authors to be inconclusive, but in addition to close cultural and morphological similarities, convincing evidence has been furnished by the fluorescent antibody technique. IMMUNOLOGY Malassezia furfur is an opportunistic fungus, a statement carrying the implication that completely normal persons are immune to the disease. Several factors may reduce resistance in localized areas of the body, principally excessive perspiration in naturally hyperhidrotic persons, or perspiration caused by occlusive clothing or by hot, humid weather. Also, poor hygiene and infrequent bathing are important causative factors. Certain individuals, however, show a distinct tendency to hypersusceptibility over long periods, which is apparently unrelated to any of the factors that allow other opportunistic fungi to become pathogenic, such as diabetes, lymphoblastomas, malignancy, malnutrition, vitamin deficiencies, or corticosteroid hormone therapy. These patients tend to have the disease more or less continuously, and to relapse very easily after treatment. In tinea versicolor this hypersusceptibility is still not understood, but in numerous examples infection has occurred in several members of a family who are related by blood line, whereas others are not affected at all, although undoubtedly living in a veritable sea of spores in skin scales shed by the diseased. T h i s finding suggests that the hypersusceptibility factor may be genetically transmitted. N o impressive success has attended the transmitting of disease experimentally onto normal areas of normal persons, or onto animals, even with the assistance of artificially produced systemic disease. THERAPY T h e patient afflicted with tinea versicolor should be reassured that the condition does not indicate a tendency toward dangerous disease, and that it usually remains simply a cosmetic problem, lacking even pruritus. In some mild cases nothing more than more frequent bathing is necessary for control. Even when more severe, this superficial infection is easily cleared by any one of a large number of topical fungicidal agents. T h e simplest remedy is sodium thiosulfate (the hypo of photographers) in 15 to 20 percent aqueous solution, with perhaps 10 percent glycerine and 20 percent isopropyl alcohol added if desired. Applied daily after a good bath with soap, this solution clears the fungi almost completely within one or two weeks; after that an occasional application at increasing intervals is sufficient. Precipitated sulfur in 2 or 3 percent strength in a vanishing-cream base works equally well. T h e odor of hydrogen sulfide characteristic of these materials is offensive to some patients, but, when large areas of the

258

The superficial mycoses

b o d y a r e i n v o l v e d , this i n e x p e n s i v e p r e s c r i p t i o n is u s u a l l y

appreciated,

e s p e c i a l l y b e c a u s e i t is e n t i r e l y f r e e of p o s s i b l e t o x i c i t y b y p e r c u t a n e o u s a b s o r p t i o n . I f e x p e n s e is n o t i m p o r t a n t , a n d if o n l y s m a l l areas a r e inv o l v e d , p r o p r i e t a r y f u n g i c i d e s m a y b e p r e f e r r e d . T h e latest o f these is g - A m i n o a c r i d i n i u m 4 - h e x y l resorcinolate (Akrinol®)* w h i c h in our opini o n seems a b l e to p r o l o n g the i n t e r v a l b e t w e e n c l e a r i n g a n d r e l a p s e m o r e than the older treatments. Q u i c k e l i m i n a t i o n of the f u n g u s d o e s n o t b r i n g c o m p l e t e s a t i s f a c t i o n t o the p a t i e n t immediately. Considerable time must be a l l o w e d for repigm e n t a t i o n of the h y p o c h r o m i c a r e a s a n d f o r r e c o v e r y of

the

normal

thickness o f the k e r a t i n layers.

Bibliography Biert, C. M . G. 1885. T i n e a versicolor of face. J. Cutan. Vener. Diseases, 3:73. Boardman, C. R., and F. D. Malkinson. 1962. T i n e a versicolor in steroid-treated patients. Arch. Dermatol., 85:44. Burke, R . C. 1961. T i n e a versicolor: susceptibility factors and experimental infection in human beings. J. Invest. Dermatol., 38:389. Gordon, M . A . 1951. Lipophilic yeastlike organisms associated with tinea versicolor. J. Invest. Dermatol., 16:267. Keddie, F. 1963. Clinical signs in tinea versicolor. Arch. Dermatol., 87:641. Keddie, F., J. Shadomy, S. Shadomy, and M . Barfatani. 1963. Intrafollicular tinea versicolor demonstrated on monomer plastic strips. J. Invest. Dermatol., 41:103. Keddie, F., and S. Shadomy. 1963. Eitological significance of Pityrosporum orbiculare in tinea versicolor. Sabouraudia, 3:21. Kistiakovsky, E. V . 1927. Pityriasis versicolor and ultraviolet rays. Arch. Dermatol. Syphil., 15:685. Lewis, G. M., and M. E. Hopper. 1936. Pseudo-achromia of tinea versicolor. Arch. Dermatol. Syphil., 34:850. Moore, M . 1940. Malassezia furfur: cultivation of organisms and experimental production of disease. Arch. Dermatol. Syphil., 41:253. Pardo-Castell6, V. 1932. Achromia parasitaria. Arch. Dermatol. Syphil., 25:785. Porto, J. A . 1953. Use of cellophane tape in diagnosis of tinea versicolor. J. Invest. Dermatol., 21:229. Sternberg, T . H., and F. Keddie. 1961. Immunofluorescence studies in tinea versicolor. Arch. Dermatol., 84:999. • Schering Corporation, Bloomfield, New Jersey.

20

Tinea nigra

INTRODUCTION is an asymptomatic, chronic fungous disease occurring almost exclusively on the palms or the palmar surfaces of the fingers. It is characterized by single or multiple dark-colored macular lesions of irregular shape. TINEA NIGRA

HISTORY Because of Castellani's studies in 1905, Manson was credited with discovering tinea nigra in 1872, but it now appears probable that he was describing tinea versicolor. T h e first report concerning a disease that definitely was tinea nigra was that of Montoya and Flores in 1898 from Colombia. In 1916 Cerquiera-Pinto published studies including observations that had been recorded, but not published, by his father, A. Cerquiera, as early as 1891. In 1921 Horta described the disease and named the fungus Cladosporium wernickii. Valuable contributions have been made by PardoCastell6 (1938), Area Leao et al. (1945), Carri6n (1950), Ramos e Silva (1930), and Aroeira Neves and Costa (1947), and relatively large groups

259

260

The superficial mycoses

of patients have recently been studied by T a p i a in Panama and Van Velsor in North Carolina. In the Western Hemisphere tinea nigra is caused by a single species of fungus, Cladosporium wernickii. In the Orient, cases that seem to be clinically identical are attributed to C. mansoni, which may or may not prove to be the same fungus. DISTRIBUTION Usually classed as a tropical disease, tinea nigra has been reported from Central America, Colombia, Brazil, Venezuela, Cuba, Puerto Rico, Southeast Asia, and Indonesia. Until recently only a few scattered cases were reported from the United States, concentrated in the southern Atlantic coastal states. Van Velsor's discovery of fifteen cases in one small area in North Carolina in 1963 should alert all clinicians to the possibility that the disease is more common than reported. T h r e e times as many females as males are involved. N o age is exempt, cases having been recorded from five months to fifty-five years of age, but 95 percent of the cases in the United States have affected individuals less than eighteen years old. Apparently Negroes do not contract tinea nigra. EPIDEMIOLOGY Fungi indistinguishable by present methods from Cladosporium wernickii are very widely distributed in nature in soil, sewage, and decaying vegetable debris. It is difficult to find a dead leaf on the ground which does not reveal species of Cladosporium. T h e mechanism that allows infection to occur is not yet clear, but an extremely important factor must be present to account for the rarity of the infection in the face of the probability that all persons contact the organisms frequently. It has not been proved that those who do become infected are immunologically defective or are ill in any other significant way. Ramos e Silva reported one case that resulted from infection acquired from a laboratory culture. A third of Van Velsor's cases were hyperhidrotic, but none of the patients had associated dermatophytosis. CLINICAL

CHARACTERISTICS

T i n e a nigra usually appears on the palms in the form of irregularly darkcolored, sharply marginated, macular lesions with little or no tendency toward scaling. In most cases only one lesion is present, but there may be multiple areas of infection on one hand; bilaterality is uncommon. T h e color varies from brownish-black or black to various shades of gray, sometimes closely simulating the stains caused on skin by silver nitrate. T h e

Tinea nigra

261

Fig. 15. Tinea nigra. Upper left and upper right: solita:y lesions in palm and palmar surface of finger, respectively; most common form. Middle right: multiple areas and bilateral involvement; rare. Middle left: multiple lesions on fingers. Lower left: appearance of finger in direct microscopic examination (KOH x 200). Lower right: appearance of Cladosporium wernickii in culture mount (x 400).

262

The superficial mycoses

color is not uniform in depth throughout the involved area, but rather mottled, with some accentuation near the border. T h e border may be circular in small lesions, but as spreading occurs it becomes irregular, polycyclic, or serpiginous. There is no inflammation, erythema, or induration, and the disease is entirely asymptomatic. PATHOLOGY There is a little thickening of the stratum corneum and a separation of the cells by the very quantity of fungous elements present, but these do not extend beneath the stratum lucidum. There is almost no reaction in the corium, but sometimes a little perivascular infíltrate is seen. DIFFERENTIAL

DIAGNOSIS

T i n e a nigra may be confused with pigmented junctional nevus, which has led to surgical excision in a few instances. Surgery can easily be avoided if the clinician realizes that the mycosis may be present, and makes direct microscopic examination of scrapings and culture to reveal the fungi. T h i s simple procedure also serves to differentiate tinea nigra from pinta, postinflammatory melanosis, or melanosis resulting from syphilis, as well as from mere staining with chemicals, pigments, or dyes. MYCOLOGY Cladosporiiim wernickii Horta 1921 is seen in epidermal scrapings as brownish to olive-tinted, branched, septate hyphae, up to 5 microns in diameter, tending to be more twisted and tortuous than those of the dermatophytes. Often the segments are separated from each other and are seen as short fragments or as arthrospores or budding cells. Sometimes small conical protrusions are formed along the hyphae, which bear budding cells of spherical, oval, or irregular shape. In culture C. wernickii grows readily. It begins as a moist, shiny, closely adherent yeastlike colony, sometimes light-colored at first but soon becoming black. Later, moist hyphae are seen around the periphery, and the center loses the shiny appearance because of the growth of a thin layer of mycelial fuzz, yielding a gray or greenish-gray color. Microscopically, the early yeastlike element is seen to consist mainly of spherical or oval budding cells, some of which possess a cross wall in the center. Short chains of such budding cells may be seen. From the periphery of an older colony specimens reveal tortuous, brown to olive, septate hyphae, along which clusters of blastospores are produced. There is close similarity to Pullularia pullulans in this stage. T h e aerial hyphae in the center of older colonies reveal spore production at the tips of branched conidiophores typical of Cladosporium (Hormodendrum).

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263

IMMUNOLOGY I n V a n Velsor's fifteen cases there were t w o instances of f a m i l i a l disease. I n one, the f a t h e r h a d h a d the i n f e c t i o n f o r e i g h t e e n years p r i o r to its d e v e l o p m e n t in a d a u g h t e r ; i n the other, a y o u n g e r b r o t h e r a c q u i r e d tinea n i g r a six years after it was diagnosed i n his sister. R e y n o l d s r e p o r t e d two sisters i n w h o m the disease was diagnosed w i t h i n a m o n t h . (See p a r a g r a p h o n e p i d e m i o l o g y for a d d i t i o n a l d a t a o n i m m u n o l o g y . ) N o successful skin or serologic tests h a v e b e e n d e v e l o p e d . THERAPY T i n e a n i g r a responds easily to almost a n y topically a p p l i e d f u n g i c i d e , especially if it is keratolytic. D a i l y a p p l i c a t i o n of W h i t f i e l d ' s o i n t m e n t is usually r e c o m m e n d e d , b u t tincture of i o d i n e is also efficient. U n d e c y l e n i c a c i d m i x t u r e s are slower, a n d oral g r i s e o f u l v i n is a p p a r e n t l y ineffective ( V a n Velsor, 1964).

Bibliography Area Leao, A. E., A. Cury, and J. M. Ferreira Filho. 1945. Tinea nigra: keratomycosis nigricans palmaris. Rev. Brasil. Biol., 5:165. Aroeira Neves, J., and O. G. Costa. 1947. T i n e a nigra. Arch. Dermatol. Syphil., 55:67. Carri6n, A . L. 1950. Yeast-like dematiaceous fungi infecting human skin. Arch. Dermatol. Syphil., 61:996. Fields, J. P. L. 1962. Case for diagnosis: tinea nigra palmaris. Arch. Dermatol., 86:828. Hitch, J. M. 1961. Tinea nigra palmaris. Arch. Dermatol., 84:318. Keddie, F. 1964. Cladosporium wernickii: infection and in vivo culture. Arch. Dermatol., 89:432. Leland, L. S. 1950. Tinea nigra in the United States. Arch. Dermatol. Syphil., 61:854. Pardo-Castell6, V. 1938. Keratomycosis nigricans palmaris. Rev. Argentin. Dermatosif., 12:255. Ramos e Silva, J. 1930. Sobre um novo caso de tinea nigra. Brasil-mid., 44:755. Ritchie, E. B., and M. E. Pinkerton. 1955. Case of tinea nigra palmaris in Texas. Arch. Dermatol., 72:467. Ritchie, E. B., and T . E. Taylor. 1964. A study of tinea nigra palmaris. Arch. Dermatol., 89:601. Smith, J. G., Jr., W . M. Sams, and F. J. Roth, Jr. 1958. Tinea nigra palmaris: a disorder easily confused with junction nevus of the palm. J. Amer. Med. Assoc., 167:312. Spiller, W. E., J. F. Mullins, and J. M. Knox. 1956. Tinea nigra. J. Invest. Dermatol., 27:187. Van Velsor, H. 1964. Tinea nigra. Arch. Dermatol., 90:59.

21 Piedra

INTRODUCTION is a fungous infection of the hair shafts of the human scalp or the beard, characterized by firm, irregularly placed and shaped nodules. T w o varieties exist, one exhibiting white, light-brown, or cream-colored nodules; in the other, the nodules are dark brown to black. PIEDRA

HISTORY Beigel first described white piedra in 1865, and four years later discussed it at length in his book, The Human Hair: Its Structure, Growth, and Diseases, calling it the "chignon fungus." Black piedra was discovered by Malgoi-Hoes in 1901. DISTRIBUTION White piedra occurs in tropical and temperate climates in Europe, the Orient, and South America, and rarely in the United States. T h e black

264

265

Piedra

variety is limited to the tropics in South America, Central America, the East and West Indies, Vietnam, and Thailand. The disease shows no predilection based on age, sex, or skin color. EPIDEMIOLOGY

Little is known of the way in which piedra is acquired. The white variety has been reported in horses and some types of monkeys, but there is little to suggest that it is transferred directly from these animals to human hairs. It has been postulated that humans may acquire piedra by swimming in stagnant water. Black piedra occurs in monkeys and chimpanzees. CLINICAL

CHARACTERISTICS

White piedra produces firm (but not stony) nodules irregularly distributed along the hair shafts. The nodules apparently form on the hairs just as they emerge from the follicles, and harden as the hairs grow outward. The masses are not very compact, and can easily be stripped from the hairs. The fungus also grows inward into the hair shafts, swelling them and weakening them so that they break easily. The nodules may coalesce or enlarge enough to surround a hair shaft entirely. Black piedra produces very hard, dark-brown to black concretions varying in size and number. They are firmly attached to the hair shafts, sometimes encircling them to form ringlike structures, swollen in the central part and tapering both distally and proximally. PATHOLOGY

As piedra limits its activities to the hair shafts, no discussion here is necessary. The appearance of the fungus in direct microscopic examination is better covered under mycology. DIFFERENTIAL

DIAGNOSIS

Piedra must be differentiated principally from a disease that used to be called trichomycosis axillaris, but is now considered to be of nonfungal origin, in which yellow, red, or black nodules are formed along the hair shafts in the axillary and pubic areas instead of in scalp and beard. This disease, as well as such developmental anomalies as monilethrix, trichorrhexis nodosa, and the nits of the head louse and the pubic louse occasionally found attached to hairs of the beard or moustache, may be eliminated from consideration by microscopic examination, which will reveal the fungi of piedra.

266

T h e superficial mycoses

MYCOLOGY Direct examination of hairs infected by white piedra reveals fungal hyphae, which fragment into arthrospores 2 to 4 microns in diameter and up to 8 microns in length. These arthrospores produce one or more buds near one end, and the process continues. Trichosporon beigelii (Rabenhorst) Vuillemin 1902 grows readily in culture on Sabouraud's medium at room temperature, producing a creamcolored, yeastlike colony, smooth at first, but soon becoming heavily wrinkled and somewhat soiled in appearance. Microscopically, hyphae are seen, which in the older parts of the colony break up into arthrospores as described above, and these then produce blastospores at one or more points. T h i s fungus does not ferment sugars. Species of Trichosporon closely answering the above description are commonly encountered as laboratory contaminants, particularly in sputum and specimens from the mouth and lips. Care must therefore be exercised in ascertaining that a fungus recovered from piedra actually represents the causative organism. Beigel accurately and fully described the pathogenic phase in the hairs, but his description of the fungus itself was less successful; he presented an illustration of it which is easily identifiable as an Aspergillus. Microscopic examination of hairs infected by black piedra reveals black nodules so firm that they are gritty when pressed between slide and cover slip. After clearing partially with K O H solution, the periphery of a nodule shows brown hyphae which bear cross walls but no arthrospores or budding cells. T h e center of the nodule contains asci, each ascus having eight single-celled fusiform ascospores, with a little filament at each end. Piedraia hortai grows slowly on artificial media and produces a firm, solid, somewhat conical, heaped-up colony, very dark brown to black in color, with only a short aerial fuzz. Microscopic examination reveals brown hyphae with many cross walls. Only rarely are asci produced to serve for complete identification. T h e asci are best studied by examination of the nodules on the hair as described above. IMMUNOLOGY Nothing is known of the imunology of piedra; the organisms probably never come close enough to the body tissues to produce any serologic changes or stimulate any antibody formation. Recurrence is common in infected persons after treatment, possibly indicating individual increased susceptibility.

Piedra

267

THERAPY Shaving the affected area removes all the diseased elements. Better hygienic methods, together with a topical fungicide, usually prevent recurrence. Mercuric chloride 1:1,000 is recommended, as are sulfur ointment in 3 percent or Formalin in 2 percent strength.

Bibliography Beigel, H. 1869. The human hair: its structure, growth, and diseases. P. 120. London: Henry Renshaw. Kneedler, W. H. 1939. Tinea nodosa of scalp in school children of South Siam. Arch. Dermatol. Syphil., 39:121. MacKinnon, J. E., and G. B. Schouten. 1942. Investigaciones sobre las enfermedades de los cabellos denominadas "piedra." Arch. Soc. Biol. Montevideo, 10:227. Patterson, J. C., S. L. Laine, and W. B. Taylor. 1962. White piedra. Arch. Dermatol., 85:534. Scott, M. J. 1951. Piedra: report of a case. Arch. Dermatol. Syphil., 64:767.

22

Miscellaneous superficial disorders sometimes attributed to fungi

OTOMYCOSIS of otologists formerly blamed fungi for this diseased condition of the external-ear canal, apparently because a few cultural studies had revealed the presence of fungal organisms. Almost any pathological process occurring in this area which permitted no definite otologic diagnosis was called otomycosis and treated as a fungal disorder, despite repeated warnings by mycologists and dermatologists. Finally, in 1945, Senturia, an otologist himself, largely settled the issue by applying adequate mycologic methods to diagnosis of the disease.

THE M A J O R I T Y

T h e fungi usually reported as pathogenic in this condition almost invariably proved to be common contaminants, spores of which are so universally borne upon the air as to be virtually ubiquitous throughout the world. Perhaps the best example is Aspergillus niger, viable spores of which exist almost everywhere except in a freshly sterilized container. It is not surprising that organisms such as these are frequently found colonizing the exudate in any areas, not only the ear canals, previously

268

Miscellaneous superficial disorders

269

diseased by another process. Dermatologists who inspect other body areas of such patients often find typical seborrheic dermatitis, neurodermatitis, psoriasis, or eczematous or allergic dermatologic processes caused by a variety of irritants, especially hair lotions and nail polish when used by people who like to scratch the ear-canal orifices. Excessive accumulations of cerumen, like exudate of any sort, even that from chronic draining middle-ear infections, are attractive to some saprophytic fungi. Only rarely is a truly pathogenic fungus recovered from the external-ear canal. If such a fungus is present, and if it is logically attributable to discharge from the middle ear, it will almost certainly reveal itself, even more dramatically, in other areas of the body. Most frequently encountered is Candida albicans, but its presence in reasonably high concentration must be proved by direct examination of material prepared with K O H solution; cultures do not suffice, for a culture can be obtained from a single cell of the fungus, obviously not enough to cause disease. A large proportion of the inflammatory element is really of bacterial origin, the most common offenders being staphylococci, streptococci, and Pseudomonas aeruginosa. Fungicides should be used only when pathogenic fungi are actually present in the ear canals. TRICHOMYCOSIS

AXILLARIS

Formerly attributed to a fungus named Nocardia tenuis, this asymptomatic disease is clinically characterized by nodules of irregular size and shape scattered along hair shafts, particularly in areas subject to perspiration, such as the axillae and pubic and perineal regions. It was recognized long ago that the three variations in color—yellow, red, and b l a c k — resulted from association with one causative fungus which had different "chromogenic" bacteria. It remained for Crissey, Rebell, and Laskis (1952) to clarify the issue by discovering a species of bacteria in a large percentage of patients afflicted with trichomycosis axillaris, which they named Cornebacterium tenuis (retaining the species name formerly given to the fungus). Cure is usually not difficult. T h e hair should be closely clipped to remove the nodules completely; habits of personal hygiene should be improved; antiperspirants should be used; and hexachlorophene soap, neomycin cream, or some other antibacterial agent should be applied locally. ERYTHRASMA T h i s superficial dermatosis prefers intertriginous areas, such as the perineal, crural, axillary, and submammary regions, though it sometimes affects the toe webs. It is characterized by rather sharply marginated areas of increased pigmentation, with or without slight scaliness, and is almost invariably asymptomatic. Under filtered ultraviolet radiation the involved

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The superficial mycoses

areas fluoresce brilliantly with a deep-red color. T h e disease was formerly attributed to a fungus called Nocardia minutissimum, consisting, as the name implies, of extremely fine branching hyphae. T h e hyphae would be small, of course, for the average diameter of the hyphae of all other known species of Nocardia measures less than 1 micron. In spite of numerous and diligent attempts at direct microscopic examination of material taken from erythrasma lesions, we have never been satisfied that we saw these delicate, branching filaments clearly delineated from those of connective tissue, fibrin, or cell outlines. T h e universally admitted fact that this "fungus" had never been successfully cultured was also disturbing; it is very odd behavior for any Nocardia. Sarkany, Taplin, and Blank (1961a), using a special medium for tissue culture containing 20 percent of added fetal bovine serum, have reported success in culturing an organism from erythrasma. T h e colony is shiny, round, translucent, and colorless, but exhibits a red fluorescence under Wood's light. Microscopically it consists of bacillary forms, often in chains, gram-positive at first, but negative in older colonies. Temple and Boardman (1962) report that red fluorescence was observable in the toe webs of some 12 percent of the persons tested, without evident correlation with erythrasma. T h e therapy of erythrasma, according to Sarkany, Taplin, and Blank (19616), is best carried out by oral administration of antibiotics; erythromycin and tetracycline are preferred. Systemic administration of penicillin and griseofulvin proved ineffective, as did topical use of all the above substances. These findings seem to confirm the opinion of these authors that erythrasma is a bacterial rather than a fungal infection.

PARONYCHIA

AND

ONYCHOLYSIS

From clinical appearance alone, these two diseases are often said to be of fungal origin, especially by those who do not depend on laboratory procedures for accurate diagnoses. It is true that fungi are frequently present in the lesions, most commonly the opportunistic pathogen Candida albicansj but at times saprophytic types, such as Geotrichum or Saccharomyces, are found. Bacteria are almost always present, and it is difficult to determine the actual etiologic role of each organism. It is likely that the trouble starts when a nail is mechanically separated from its eponychial fold above, or its bed below; then maceration and opportunistic microbes keep the process active. (See chap. 13 for more details on this subject.)

Bibliography Castellani, A., and A. G. Wilkinson. 192a. Observations on trichomycosis axillaris flava, rubra, and nigra. Brit. J. Dermatol., 34:255.

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Crissey, J . T., G. C. Rebell, and J . J . Laskis. 1952. Studies on the causative organism of trichomycosis axillaris. J . Invest. Dermatol., 19:187. Michaelides, P., and H. Shatin. 1952. Erythrasma fluorescence under Wood's light. Arch. Dermatol. Syphil., 65:614. Sarkany, I., D. Taplin, and H. Blank. 1961a. Erythrasma: a common bacterial infection of the skin. J . Amer. Med Assoc., 177:130. . 1961b. T h e etiology and treatment of erythrasma. J . Invest. Dermatol., 37=283. . 1962. Incidence and bacteriology of erythrasma. Arch. Dermatol., 85:578. . 1963. Erythrasma: a bacterial disease. Proc. 12th Intern. Congr. Dermatol. II: 1010. Amsterdam: Excerpta Medica Foundation.

2 3

Mycoses of the eye

the years there have been occasional reports of eye involvement in various mycotic infections, but the incidence began to increase sharply about 1954. T h i s increase was due partly to improved diagnostic methods, but to a much greater extent was caused by widespread and indiscriminate use of corticosteroids in ocular therapy. T h i s practice has influenced the frequency of infection not only by truly pathogenic fungi, but also by species not ordinarily considered pathogenic. Suie and Havener (1963) have presented an excellent review of the entire subject.

THROUGHOUT

TYPES

OF O P H T H A L M I C

INVOLVEMENT

Corneal ulcers.—Ulcers that do not appear typical for herpes simplex and do not readily yield adequate proof of bacterial causation should be investigated for fungi as early as possible, before hypopyon begins. Although the discharge from the affected eye may reveal fungal elements when stained appropriately by Gram's method or PAS, scrapings from the ulcer 272

Mycoses of the eye

273

itself are more satisfactory, both for direct microscopic examination and for implantation of cultures. Candida albicans is occasionally the invader, but other species of Candida and species of the genera Blastomyces, Aspergillus, Sporotrichum, Nocardia, Actinomyces, Fusarium, Coccidioides, Neurospora, Hormodendrum, Monosporium, Volutella, and Glenospora have been reported. Conjunctival involvement.—Many of the above organisms, as well as species of Rhinosporidium, may affect the conjunctiva. Endophthalmitis.—This disease, caused by fungi, may complicate intraocular surgery or penetrating injury, appearing at the least in a week and sometimes months later (Suie and Havener, 1963). T h e infection develops more rapidly if the inoculum of organisms is large, or is placed near a vascular part of the eye. T h e eye becomes red and painful and usually develops a hypopyon, which may spontaneously disappear. More often localized grayish infiltrates appear within the vitreous humor and gradually become more extensive. Diagnosis is made by smear and culture of aspirated aqueous or vitreous humor. Orbital involvement.—The orbit is occasionally affected when disease of the central nervous system is caused by fungi. Phycomycosis (mucormycosis) in severely acidotic diabetics is probably the most common disease, but infection has been caused by Cryptococcus neoformans, Coccidioides immitis, Nocardia asteroides, and Blastomyces dermatitidis. Sporotrichum schenckii and Blastomyces brasiliensis may invade the eye from the outside. T H E R A P Y OF INFECTIONS

OPHTHALMIC

FUNGOUS

Corticosteroids, which unquestionably enhance fungus growth in vivo and are of no benefit to injured or infected eyes (Suie and Havener, 1963), are contraindicated. T h e harmful effect of broad-spectrum antibiotics has probably been overrated; they should not be withheld if bacterial infection seems to be an important factor. Atropinization is usually advisable. Amphotericin B is the best drug for the treatment of most fungal infections of the eyes. It is prepared in a 0.3 percent suspension in 5 percent glucose solution or distilled water (not saline) for use as instilled drops as frequently as every fifteen minutes, or up to a total of 0.125 mg may be injected subconjunctival^. It is reasonably well tolerated, but even by the latter route there is no appreciable intraocular penetration. Intravenous amphotericin B may be administered in the usual way (see chap. 3), but the intraocular levels of the drug thus obtained are not high. T h e treatment of intraocular fungous infections is therefore quite unsatisfactory. Intraocular injections are sometimes able to destroy the fungi, but usually result in intraocular scarring which destroys useful vision.

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The superficial mycoses

Nystatin, either as a topical ointment containing 100,000 units per gram, or by subconjunctival injection of 5,000 units suspended in 0.5 cc of saline solution, is reasonably well tolerated. It is too toxic for intravenous use, and probably also for intraocular injections.

Bibliography Anderson, B., S. S. Roberts, C. González, and E. W. Chick. 1959. Mycotic ulcerative keratitis. Arch. Ophthalmol., 62:169. Arnold, R., and J . Whildin. 1942. Rhinosporidiosis of conjunctiva. Amer. J . Ophthalmol., 25:1227. Blodi, F. C., and W. C. Huffman. 1958. Cicatricial ectropion caused by cutaneous blastomycosis. Arch. Ophthalmol., 59:459. Elles, N. B. 1941. Rhinosporidiosis infection in eye. Arch. Ophthalmol., 25:969. Faulkner, R. F. 1962. Ocular coccidioidomycosis. Amer. J . Ophthalmol., 53:822. Giles, C. L., and H. F. Falls. 1961. Evaluation of amphotericin B in histoplasmosis chorio-retinitis. Amer. J . Ophthalmol., 51:588. Gingrich, W. D., and M. E. Pinkerton. 1962. Anaerobic Actinomyces bovis corneal ulcer. Arch. Ophthalmol., 67:549. Mitsui, Y., and J . Hanabusa. 1955. Corneal infections after cortisone therapy. Brit. J . Ophthalmol., 39:244. Montana, J . A., and T . W. Lery. 1958. Effect of fungistatic agents on corneal infections with Candida albicans. Arch. Ophthalmol., 60:1. Smith, C. H. 1953. Ocular actinomycosis. Proc. Roy. Soc. Med., 46:209. Suie, T., and W. H. Havener. 1963. Mycology of the eye: a review. Amer. J . Ophthalmol., 56:63. Theodore, F. H., M. L. Littman, and E. Almeda. 1961. The diagnosis and management of fungus endophthalmitis following cataract extraction. Arch. Ophthalmol., 66:168. Tye, A. A. i960. Actinomycotic infections of the lachrimal canaliculi. Trans. Ophthalmol. Soc. Austral., 20:121.

24

Fungi as occupational hazards

UNDER CERTAIN circumstances the acquisition of a fungous infection may legitimately be attributed directly to the patient's occupation, but much more often fungi are wrongly blamed. Because such an illness may be compensable as an industrial accident, it is imperative that the diagnosis be supported by comprehensive laboratory and clinical evidence. In most instances it is not necessary that the actual acquisition of the disease be attributable to the occupation, for if it can be shown that occupational factors have increased the severity of the infection, the exacerbated part of the ailment is compensable.

COMPENSABLE INFECTIONS

SUPERFICIAL

FUNGOUS

Prior to any decision as to the industrial nature of a superficial infection, the presence of fungi in the diseased tissues must be proved, either by direct microscopic examination or by cultural methods. Occasionally a der275

276

The superficial mycoses

matophyte infection has been compensated as occupational by demonstrating that the patient, in the course of his work, had to contact a fellow worker who was harboring the disease. Examples are eruptions on the hands of bank tellers, of persons working close together on assembly lines, and of those whose work causes excessive perspiration. Such decisions are often extremely difficult to make fairly, because the nonindustrial part of the employee's total time may easily present equal opportunities for infection. The discovery that the patient's feet are chronically infected in the same way as his hands may weigh against the compensability. Exposure of the skin to chemical irritants may sufficiently exacerbate a previously quiescent dermatophytosis to warrant compensation, at least until the earlier stability has been reestablished. Even without the knowledge that a previous chronic fungous disease existed, compensation is likely to be awarded, for dermatophyte fungi do not like to attack vesicular, denuded areas of the skin, but prefer instead hyperkeratotic conditions. It is also well documented that normal serum inhibits, rather than supports, dermatophytes. The presence of a fungous infection may easily make a person's hands more susceptible to contact dermatitis, and such workers should not be placed in positions exposing them to hazards of this kind. A common industrially caused disease is paronychia, often accompanied by onycholysis. It afflicts food handlers, especially those preparing food for canning, salad makers, pie makers, laundry workers, and dishwashers, and often waiters and bartenders. These disorders may be of bacterial instead of fungal origin, but moniliasis (caused by Candida albicans) is frequently a contributing cause. In addition to the nails, the skin of the hands, especially the finger webs, may be infected by this fungus. During World War II literally thousands of service personnel were said to have acquired "rare fungous diseases" in one of the war areas outside the continental United States, usually a tropical region such as the South Pacific or Africa. A high percentage of these diseases, when subjected to competent laboratory investigation, proved to be either nonmicrobial dermatoses or bacterial infections. Those that actually proved to be of fungal origin almost invariably yielded in culture one of the common dermatophytes already known to be worldwide in distribution. In fact, there is more evidence that United States service personnel carried dermatophytes overseas with them on their feet, to infect natives who began to wear sweat-inducing shoes for the first time, than the other way around. The only fungous skin disease present in the South Pacific which is not also common in the United States is tinea imbricata, and rumors that a few Americans acquired it while on duty have not been documented, to our knowledge. In spite of these facts, many instances of chronic dermatophytosis, usually that caused byTrichophyton rubrum, have been judged

Fungi as occupational hazards

277

compensable as occupationally acquired, and the person afflicted has usually been awarded a moderate percentage of disability on a more or less permanent basis. COMPENSABLE

SYSTEMIC

FUNGOUS

INFECTIONS

In many instances sporotrichosis has been legitimately adjudged compensable, particularly in gardeners working with thorny plants and florists handling similar material or sphagnum moss. When workers unloading bricks and pottery ware packed in straw later demonstrated to contain viable Sporotrichum schenckii have become infected, they have received compensation. Several thousand workers in South African gold mines have acquired sporotrichosis from the timbers supporting the roofs of the shafts. Coccidioidomycosis has often been properly attributed to the patient's occupation. During the early years of World War II thousands of military personnel were exposed to Coccidioides immitis in California, Arizona, and Texas, and many serious cases resulted; all of them were judged to be of occupational origin, and the persons afflicted were compensated. T h e incidence of the infection was sharply reduced by planting shrubbery and grass in many dust-producing areas, and sprinkling water frequently over others. If a person working in a known or subsequently proved endemic area where he is more subject to the inhalation of terrestrial dust than he would be in ordinary life contracts a pulmonary coccidioidal infection, he has been awarded compensation. Examples are operators of street sweepers and earth-moving equipment, construction engineers, and certain types of agricultural workers. If a person hired in an area nonendemic for Coccidioides and subsequently sent into an endemic region to work at any sort of occupation acquires a coccidioidal infection, it has frequently been concluded that the infection was industrially acquired and is therefore compensable. Braceros hired in Mexico, or in nonendemic areas of California, and later sent to the San Joaquin Valley or to other established endemic foci have often been so compensated. A mortuary attendant who acquired primary cutaneous chancriform coccidioidomycosis from a cadaver in the course of his employment received compensation. T w o laboratory workers who acquired the same kind of primary cutaneous infection through their work were also compensated. In contrast, coccidioidomycosis first appearing in the skin as a deep abscess is probably derived by dissemination from the lungs, and a bump or a bruise at that point should not be considered conclusive evidence of industrial accident. Several nursing attendants acquired the pulmonary form by inhaling spores of Coccidioides while assisting a physician in removing a cast from

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The superficial mycoses

the limb of a patient with a draining coccidioidal lesion in the bone. T h e fungus was growing in the saprophytic stage in the exudate accumulated underneath the cast. North American blastomycosis has been adjudged compensable in at least one instance, the fourth case reported in Wilson, Cawley, Weidman, and Gilmer (1955). T h i s patient was also a mortuary attendant acquired the disease from a cadaver. T h e other three cases reported

who (ibid.)

were physicians who became infected during autopsies or in the laboratory; possibly they could have presented enough evidence to have achieved a verdict of compensability, but whether or not they did so is not known. Aspergillosis of the lungs contracted by handlers of dusty grain has been reported as compensable.

Bibliography Downing, J. G. 1955. Dermatophytosis and occupational dermatitis. J. Amer. Med. Assoc., 125:196. Foerster, H. R. 1924. Sporotrichosis. Amer. J. Med. Sci., 167:54. Gastineau, F. M., L. S. Spolyer, and E. Haynes. 1941. Sporotrichosis: report of six cases among florists. J. Amer. Med. Assoc., 117:1074. Hartung, M., and K. Salfelder. 1962. Histoplasmosis with fatal outcome as an occupational disease in a mycologist. [In German.] Intern. Arch. Gewerbe Pathol., 19:270. Hayes, W. N. i960. Sporotrichosis in employees of a tree nursery. Gen. Practice, 22:114. Lane, C. G. 1938. Mycotic skin infections in relation to industrial dermatoses. Ybk. Dermatol. Syphil., p. 29. Levan, N. E., and M. Q. Kwong. 1963. Coccidioidomycosis: occupational aspects. Arch. Dermatol., 87:511. Peck, S. M., L. Botvinick, and L. Schwartz. 1944. Dermatophytosis in industry. Arch. Dermatol. Syphil., 50:170. Robinson, H. M., Jr. 1949. Industrial sporotrichosis. Southern Med. J., 42:343. Sporotrichosis infection in mines of the Witwatersrand: a symposium. 1947. Proc. Transvaal Mine Med. Officers' Assoc., Johannesburg. Trimble, J. R., and J. Doucette. 1956. Primary cutaneous coccidioidomycosis. Arch. Dermatol., 74:405. Wilson, J. W., E. P. Cawley, F. D. Weidman, and W. S. Gilmer. 1955. Primary cutaneous North American blastomycosis. Arch. Dermatol. Syphil., 71:39. Wilson, J. W., C. E. Smith, and O. A. Plunkett. 1953. Primary cutaneous coccidioidomycosis: the criteria for diagnosis. Calif. Med., 79:233.

25

Morpho of fungi

constitute a large group of living organisms, none of which possess chlorophyll, the green pigment found in most higher plants and algae. Lacking chlorophyll, they are unable to use the carbon dioxide of the air to combine with water for the production of carbohydrates by photosynthesis. As a result of their inability to construct their own carbohydrate food from raw materials, they must depend on previously elaborated carbon compounds for their supply. Although carbohydrates are the most suitable of these, many fungi utilize fats, proteins, higher alcohols, and organic acids. Fungi obtain their food either by infecting living organisms as parasites, or by attacking dead organic matter as saprophytes. Most parasitic fungi can be cultivated saprophytically on synthetic media. THE FUNGI

There are two distinct phases in the life cycle of fungi, the vegetative or somatic phase and the reproductive phase. SOMATIC

STRUCTURES

T h e vegetative fungal thallus consists of more or less elongate, septate or nonseptate, branching filaments. Each filament is known as a hypha (pi., 281

Medical mycology

282

hyphae), and collectively they form the mycelium. The hyphae are tubular structures, with cell walls of varying thickness, lined with a layer of cytoplasm. The composition of the cell wall is variable among different fungi, and often in the same individual at different stages of maturity. In some forms cellulose is probably the chief constituent. In most of the higher fungi the wall is composed chiefly of chitin in combination with other substances. There are two main types of mycelium: in one the hyphae are divided into cells by the formation of cross walls (septa); in the other regular septations are absent and the whole hyphal filament consists of a single cell. In fungi that lack septa numerous nuclei are embedded in the peripheral cytoplasm and are scattered more or less uniformly throughout its mass. In septate hyphae each cell may contain one, two, or several nuclei. Uninucleate cells are characteristic in some fungi, and binucleate cells, in others; multinucleate cells occasionally occur in most fungi, especially in old hyphal tips where elongation and septation are no longer occurring. The nuclei of the vegetative portions of fungi are very minute and difficult to study. In the sexual stages of many fungi the nuclei are larger, and may be seen to possess a nuclear membrane, a nucleolus, and definite chromosomes. Vacuoles, oil droplets, and protein granules are commonly present in the cytoplasm. The mycelium of many fungi develops specialized hyphae as absorbing or anchoring organs. In such forms as Rhizopus, rootlike rhizoids are formed which penetrate into the substratum. Most saprophytic fungi produce mycelium in direct contact with the substratum and absorb nourishment by direct diffusion through the hyphal walls from the disintegrating organic matter. The mycelium of plant parasitic fungi grows on the sur-

A

B

Fig. 16. Somatic structures. A. Unicellular fungus. nating spore. C. Septate mycelium. D. Nonseptate E. Rhizoids.

B. Germimycelium.

Morphology of fungi

283

face of the host, or, more often, inside the host between the cells or penetrating into them. If the host cells are killed food is absorbed directly into the mycelium. In many of the obligate plant parasites the intercellular hyphae produce specialized knotlike or branched protuberances (haustoria), which absorb food directly from the living protoplasm of the host. Fungi parasitic on man or animals are not known to produce haustoria. Hyphal development usually originates from the germination of a spore by the protrusion of a germ tube through the spore wall. T h e contents of the spore pass into the germ tube, which continues to elongate by apical growth. As growth continues, branching and development of septa may or may not take place as the mycelium develops. As growth of the mycelium is usually equal in all directions, a circular colony develops in culture. In some fungi the hyphae become organized into a loosely compact tissue called prosenchyma. When this tissue is formed of closely packed cells resembling the parenchyma cells of higher plants, it is called pseudoparenchyma. Two types of somatic and reproductive bodies, the stroma and the sclerotium, are formed from these tissues. A stroma is a loose compact structure in which fruiting bodies are formed. A sclerotium is a dry, hard, resting body produced by many fungi when environmental conditions are not favorable for growth and normal sporulation. The sclerotia may remain dormant for long periods of time and germinate upon the return of favorable conditions. REPRODUCTION When the vegetative mycelium has reached maturity and has stored up a reserve of food, or when environmental conditions are unfavorable or the food supply has lessened, reproductive structures (spores) are developed. Spores may be defined as characteristically formed cells or groups of cells which separate from the mother plant and are capable of developing into new individuals, having all the characteristics typical of the species. Fungous spores not only perpetuate the species but function as organs of dispersal, multiplication, and resistance to unfavorable environmental conditions. They are of many types and are produced in many different ways. T h e type of definitive spore formed and the way in which it develops are the basis for classification of the fungi. Spores are either sexual, that is, formed directly or indirectly after the fusion of two compatible nuclei from two similar or dissimilar cells, or asexual, formed by the division of a single cell without the fusion of nuclei. Some fungi reproduce by one method, and others by both. Asexual spores may be developed during one stage in the life history, and sexual ones during another. In many fungi more than one type of asexual spore may be produced. Asexual spores may be surrounded by a membrane during their development, and are termed endogenous spores. Exogenous spores are formed

284

Medical mycology

from or on the mycelium in different ways, but are always borne free and never enclosed by a membrane during development. Vuillemin divided exogenous spores into two main divisions, thallospores and "conidia vera." Thallospores are formed directly from normal vegetative cells, whereas conidia are specialized cells abstricted from the vegetative mycelium. Three types of thallospores are differentiated: blastospores, arthrospores, and chlamydospores. Blastospores are spores or undifferentiated cells formed as buds, which are abstricted from the mother cell and are capable of further growth by the formation either of other buds or of germ tubes. Blastospores are characteristic of yeasts and yeastlike fungi, but may also be produced by mycelium and pseudomycelium. Arthrospores develop by the disarticulation of specialized or nonspecialized cells of the vegetative hyphae without change of shape or thickening of the cell wall. Chlamydospores are formed by the rounding up and thickening of the walls of the vegetative hyphal cells. They are normally found intercalary in the hyphae, but may be formed terminally on short stalks. Care must be used to differentiate between real terminal chlamydospores and thickwalled conidia. These thick-walled spores serve as resting spores and remain viable for a long time after the mycelial cells are dead and disintegrated. Asexual spores are formed in great abundance, in or on specialized spore-bearing structures, and serve to disseminate the species. There are two types of endogenous asexual spores, sporangiospores and zoospores, and one type of exogenous spore, the variously modified conidium. Sporangiospores and zoospores are produced in sporangia, developed from a modified tip of a hyphal branch. A cell at the tip of a filament of mycelium is cut off from the rest of the filament by a cross wall, and the

Fig. 17. Thallospores. A. Blastospores. B. Arthrospores. C. Chlamydospores.

Morphology of fungi

285

Fig. 18. Endogenous asexual spores. A. Zoospores. B. Sporangiospores. dense cytoplasm becomes divided into small portions, each of which develops a membrane. T h e spores are delimited by cleavage planes progressing inwardly from the periphery of the sporangium. In the water molds the spores do not develop a wall and, when released from the sporangium, are motile zoospores. T h e sporangiospores develop a hard wall and are nonmotile. Sporangia producing sporangiospores are usually borne on a differentiated simple or branched stalk known as a sporangiophore. T h e upper end of the sporangiophore usually ends in a swollen subspherical vesicle, the columella, which extends into the sporangium proper. T h e sporangial membrane is usually thin and is easily ruptured, permitting the sporangiospores to be air-dispersed. T h e membrane is frequently covered with fine spicules of calcium or other waste mineral salts. Conidia are thin-walled, exogenous, single-celled or multicellular spores abstricted from the tip of specialized hyphal branches. These hyphae, usually modified and differentiated from the vegetative mycelium, are known as conidiophores. Some conidia are borne directly on the mycelium and are freed only by the death of the mycelium; others are borne on very short sterigmata, as in Sporotrichum. Conidia may be abstricted singly from the tips of the conidiophore or be formed in heads or chains. When in chains they may be abstricted from the conidiophores and shoved upward, or they may bud apically from one another. Some fungi produce modified conidia borne at the tip of a tubular or flask-shaped specialized conidiophore, the phialide. In the pathogenic species Phialophora verrucosa the spore is borne at the base of an urn-shaped structure with an expanded cuplike tip. These spores, sometimes spoken of as phialospores, accumulate in a ball at the mouth of the cup and are held together by a gelatinous slime. Another specialized type of conidium is the aleuriospore, which is differentiated from the true conidia by the fact that it is not set free when mature, but is liberated only by the death of the vege-

286

Medical mycology

tative cell immediately below the point of attachment. Aleuriospores are characteristic of the spores of the dermatophytes, and of Histoplasma capsulatum and Blastomyces dermatitidis. Many fungi, as in the genera Microsporum and Trichophyton, form two types of conidia from the same vegetative mycelium. Here unicellular microconidia (microaleuriospores) and larger fusiform macroconidia (macroaleuriospores) are developed. Other fungi producing two types of conidia are Histoplasma, Fusarium, and Sepedonium. The nature and origin of conidiophores are variable, and are important in differentiating and characterizing various genera of Deuteromycetes. Simple or elaborately branched and modified conidiophores may arise directly from the mycelium or from a stroma composed of a modified mass

Morphology of fungi

Fig. 20. Asexual fruiting bodies. A. Pycnidium. B. C. Sporodochium.

287

Coremium.

of pseudoparenchymous cells. They may be free on the mycelium, aggregated, or enclosed in a fruit body composed of sterile modified cells. If the conidiophores arise in a group from a thin stromatic base the fruiting structure is termed an ascervulus. Pycnidia are ovate or spherical closed fruit bodies with the conidiophores forming a lining on the inside wall. Coremia are formed by the aggregation of the elongated conidiophores into a fascicle. In some fungi the conidiophores are very short and are aggregated on a cushion-like stroma, forming a sporodochium or tubercle. Sexual spores resulting from the fusion of two compatible nuclei and the subsequent reduction division are produced by Phycomycetes and Ascomycetes less frequently than are the asexual spores. Well-defined sex organs and gametes are easily observed in relatively few fungi. Some species produce distinguishable male and female sex organs, or gametangia. The male gametangium is called the antheridium, and the female gametangium, the oogonium. If the antheridia and the oogonia are produced on the same thallus, the fungus is said to be homothallic, and a single thallus can reproduce sexually by itself. When the sex organs are produced on different thalli, the fungus is heterothallic. A single heterothallic species cannot normally reproduce sexually by itself, as it is either male or female. Some species of fungi do not produce differentiated sex organs, but develop gametangia on the somatic hyphae. These gametangia are morphologically similar and in some species are formed on the same thalli (homothallic); in others two compatible thalli must come in contact before functional gametangia are produced. Sexual spores of phycomycetes The Phycomycetes are divided into two subclasses, Oomycetes and Zygomycetes, on the basis of their sexual reproduction. In a representative

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Fig. 21. Sexual spores of Phycomycetes. A. Oospores of Saprolegnia. B. Zygospores of Rhizopus. C. Zygospores of Zygorhynchus.

oomycete, Saprolegnia, the oogonia are spherical, ovoid, or pyriform, and develop from the vegetative mycelium. They are usually stalked and borne terminally or laterally, although some species produce intercalary oogonia singly or in chains. At maturity the oogonial wall may be smooth or papillate and is often pitted, especially where antheridia attach. Uninucleate oospheres develop within the oogonia, the number varying, according to species, from one to many. Antheridial branches develop as tubular side branches on the vegetative mycelium. They may be formed from the oogonial stalk, from the same mycelium as that originating the oogonia, or from an entirely separate thallus. Antheridial branches are attracted to the developing oogonia toward which they grow, eventually coming into contact with and, in some species, completely entangling and growing over the wall. In the area of contact antheridia are cut off at the apex of the antheridial branches in which, the male nuclei are produced. Fertilization tubes are produced from the antheridia of many species. These tubes penetrate the oogonial wall, through the pits if these are present, grow into the oogonium, reach the oospheres, and effect fertilization, after which the oospore develops. The male nuclei are discharged directly into the cytoplasm of the oospheres. After fertilization the zygotes become oospores by the deposition of a thick wall. In some species oospores are developed parthenogenetically; motile gametes are lacking and gametes are never shed into the environment. In the Zygomycetes no definite sex organs are produced, and the gametangia are developed from branches of the somatic hyphae. In some genera which are homothallic, both gametangia are developed on the same thallus, while in other heterothallic genera the gametangia arise from different thalli. Sexual reproduction is known to occur in most Mucorales, but in some heterothallic genera it is rarely seen because only

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289

one of the mating strains is represented. Mating strains, usually designated as "plus" or "minus," are morphologically similar, although in some strains there is a slight difference in the size of the gametangia. In Rhizopus nigricans, plus hyphae and minus hyphae, when they lie close together, put out short clublike branches which are multinucleate and rich in protoplasm. These branches meet end to end and gradually push the two hyphae apart. The tips of the branches become filled with dense protoplasm and a wall is formed, cutting off the tip from the rest of the branch. The tip cells are regarded as multinucleate gametangia, and the remainder of each branch is called a suspensor. The double wall between the gametangia is broken down and the content of the two gametangia mingles. Multiple fusion of nuclei in pairs occurs, and forms a zygote with numerous diploid nuclei. The zygote continues to enlarge with the formation of a thick, heavy, and spiny or roughened wall. After a prolonged rest period the zygospore germinates by forming a short hypha with a single sporangium at its tip, in which nonmotile sporangiospores develop. Sexual reproduction in ascomycetes The most characteristic and uniform structure in the Ascomycetes is the ascus, which arises as a result of a direct or an indirect sexual process by which there is a fusion of compatible nuclei. These nuclei fuse to form a diploid nucleus which immediately undergoes meiosis to produce four haploid nuclei. Ascospores may develop by free cell formation around these nuclei, but in the majority of asci there is a mitotic division of the nuclei, and eight ascospores are formed. In some of the simple Ascomycetes, as in the yeast Schizosaccharomyces, two contiguous yeast cells send out minute tubelike processes which meet and fuse. The nucleus from one cell passes into the other cell, where fusion of the nuclei occurs. The single nucleus resulting undergoes division three times to form eight daughter nuclei. Each of these becomes surrounded by a certain amount of reserve material, and a spore wall is formed. The zygote thus becomes the ascus, and the spores become ascospores. Among some of the simple Ascomycetes with a true mycelium sexual reproduction is also by conjugation, as in Eremascus fertilis. Here two contiguous cells in a filament of mycelium send out budlike processes. These unite, their nuclei fuse, and meiosis of the diploid nucleus immediately follows, giving rise to four ascospores. In most of the Ascomycetes the process is not so simple. The sex organs (ascogonia and antheridia) are frequently not distinct, and are seldom observed in culture. They arise on the vegetative hyphae which may be homothallic and heterogamous or heterothallic. The ascogonium arises as a swollen branch and the antheridium as a fine filament which is frequently coiled around the ascogonium. A male nucleus enters the ascogonium which now becomes binucleate. The nuclei do not unite but

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divide simultaneously in pairs so that the ascogonium has many paired nuclei. Later, buds arise from the perimeter of the ascogonium and develop new hyphal filaments, the ascogenous hyphae. Pairs of nuclei move into the buds and divide, so that each cell of the ascogenous hyphae is binucleate. Further binucleate buds arise and are cut off from the ascogenous hyphae. These are the young asci in which fusion of the nuclei occurs, forming a spore mother cell with a diploid nucleus. Meiosis followed by a mitotic division then occurs, so that the young ascus has eight haploid nuclei. A part of the cytoplasm of the ascus gathers around each nucleus, and is soon set off from the remaining cytoplasm by a cell wall. T h e ascospores are thus formed by free cell formation. Ascospores may remain one-celled, or they may become divided by septation into multicellular spores, each cell of which is capable of germinating to form a new vegetative hypha. T h e asci may be borne free on the mycelium or may be enclosed in a fruiting body, or ascocarp. T h e simplest type of fruiting body is the cleistothecium in which the asci are scattered or irregularly arranged. In the Gymnoascaceae the cleistothecium has a loose floccose covering, often ornamented by heavily walled peridial filaments. In the Eurotiaseae the fruiting body is a closed structure with a wall two or three layers thick composed of compact cells resembling collenchyma. T h e characteristic fruiting body of the large subclass Pyrenomycetes is the perithecium. It is a closed spherical, subspherical, or flask-shaped fruiting body having a definite opening, the ostiole, with the asci arranged in a parallel series. T h e ostiole may be a simple pore, or may be elongated into a neck. Perithecia may be membranous, leathery or hard and carbonaceous, and they possess walls of varying thickness. T h e asci are usually club-shaped, ovate, or cylindrical, and have the ascospores arranged in one or two rows. Arising from a hymenial layer lining the perithecia in a parallel series, they are frequently separated from each other by sterile threads called paraphyses.

A

B Fig. 22. Sexual fruiting bodies of Ascomycetes with asci and ascospores. A . Cleistothecium. B. Perithecium. C. Apothecium.

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B

C

Fig. 23. Sexual spores of Basidiomycetes. A. Basidiocarp of a mushroom. B. Section of gill showing hymenial layer. C. Basidia and basidiospores.

T h e third type of ascocarp is the apothecium, an open disklike, cupor saucer-shaped, fleshy or leathery fruiting body. T h e hymenium, composed of asci and paraphyses, is exposed at maturity as an inner lining of the cup. T h e base and the side walls of the cup are composed of sterile tissue. This type of ascocarp is found in a large group of saprophytic fungi called Discomycetes. Sexual spores of basidiomycetes No recognizable male or female structures are present in the Basidiomycetes. Basidiospores germinate and form hyphae which, though multinucleate, eventually become septate and uninucleate; such hyphae constitute the primary mycelium. Primary mycelial filaments of opposite mating type come in contact and two cells fuse. T h e nuclei of these cells do not fuse but divide simultaneously, and a secondary mycelium develops in which the cells are binucleate. This binucleate mycelium forms the vegetative thallus and eventually the basidiocarps. In the common mushrooms the basidiocarp is made up of a stalk and an umbrella-shaped cap, the pileus, composed of modified binucleate mycelium. On the underside of the cap, gills extend downward. From the central part of the gills mycelial tips extend outward forming an hymenial layer. T h e tip ends of the hymenial hyphae become swollen and club-shaped and are cut off by a septum, forming a spore mother cell, or basidium. T h e two nuclei in the young basidium fuse and then undergo meiosis, giving rise to four haploid nuclei. Four sterigmata, from which four buds arise, are formed on the apex of the basidium. T h e four nuclei pass out into these buds, which enlarge and become basidiospores.

Bibliography Ainsworth, G. C. 1961. A dictionary of the fungi. Kew, Surrey: Commonwealth Mycological Institute.

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Alexopoulos, C. J . 1952. Introductory mycology. 2d ed., 1962. New York: John Wiley 8c Sons. Alexopoulos, C. J., and E. S. Beneke. 1962. Laboratory manual for introductory mycology. Minneapolis: Burgess Publishing Co. Bakerspigel, A. 1957. The structure and mode of division of the nuclei in the yeast cells and mycelium of Blastomyces dermatitidis. Canad. J . Microbiol., 3:923-936. Bary, A. de. 1887. Comparative morphology and biology of the fungi, mycetozoa and bacteria. Trans. H. E. Garnsey. London: Clarendon Press. Benjamin, Chester R. 1955. Ascocarps of Aspergillus and Penicillium. Mycologia, 47:669-686. Bessey, E. A. 1950. Morphology and taxonomy of fungi. Philadelphia: Blakiston Co. Breslau, A. M., T . J . Hensley, and J . O. Erickson. 1961. Electron microscopy of cultured spherules of Coccidioides immitis. J . Biophys. Biochem. Cytol., 9:627637Christensen, Clyde M. 1951. The molds and man. Minneapolis: University of Minnesota Press. Dennis, R. W. G. i960. British cup fungi and their allies. London: The Ray Society. Duddington, C. L. 1957. The friendly fungi. London: Faber and Faber. Gäumann, E. 1926. Vergleichende Morphologie der Pilze. Jena: Gustav Fischer. Gray, W. D. 1959. The relation of fungi to human affairs. New York: Henry Holt. Gwynne-Vaughan, H. C. I., and G. Barnes. 1927. The structure and development of the fungi. 2d ed., 1937. London: Cambridge University Press. Henrici, A. T . 1930. Molds, yeasts, and actinomycetes. New York: John Wiley 8c Sons. Hughes, S. J . 1953. Conidiophores, conidia, and classification. Canad. J . Botany, 3i:577-659Ingold, C. T . 1961. T h e biology of fungi. London: Hutchinson Educational Ltd. Lewis, G. M., M. E. Hopper, J . W. Wilson, and O. A. Plunkett. 1958. An introduction to medical mycology. 4th ed. Chicago: Year Book Medical Publishers. Lilly, V. G., and H. L. Barnett. 1951. Physiology of the fungi. New York: McGrawHill. Moreau, F. 1952-1953. Les champignons. Encycl. Mycol. Vols. 22, 23. Paris: Paul Lechevalier. Nickerson, W. J . 1947. Biology of pathogenic fungi. Waltham, Mass.: Chronica Botanica Co. Ramsbottom, J . 1953. Mushrooms and toadstools. London: Collins. Skinner, C. E., C. W. Emmons, and H. M. Tsuchiya, revisers. 1947. Molds, yeasts, and actinomycetes, by A. T . Henrici. 2d ed. New York: John Wiley 8b Sons. Smith, G. M. 1955. Cryptogamic botany. New York: McGraw-Hill. Smith, G. M., and H. Raistrick. 1942. An introduction to industrial mycology. 2d ed. London: Edward Arnold Ltd. Stevens, F. L. 1913. The fungi which cause plant disease. New York: Macmillan. Wolf, F. A., and F. T . Wolf. 1947. The fungi. New York: John Wiley 8c Sons. 2 vols.

26

Nutrition of fungi

SAPROPHYTISM the lack of chlorophyll, all fungi must obtain their organic food ready-made. Most fungi are saprophytic; that is, they derive their nourishment from dead organic remains of plants or animals, but not from the living organisms themselves. Practically all organic substances are subject to attack by fungi. Complete organic decay of waste products is brought about by many different fungi and bacteria acting in unison or in succession. Here there is much competition among different organisms, and the waste products of some are poisonous to others. Various saprophytic fungi produce many kinds of enzymes capable of breaking down various compounds. Cellulose, lignin, chitin, hair, oils, fats, simple and complex sugars, proteins, various organic acids, asparagine, peptone, gelatin, glycerin, and the like are utilized as foods when the necessary mineral elements are present. Some fungi are capable of growing in solutions of high salt concentration, such as pickle brine, while others grow in jams and jellies high in sugar content. Fungi are frequently found growing in fingerprints on camera lenses. OWING TO

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Some saprophytic fungi are limited in their organic foodstuffs and some require the presence of various growth factors and amino acids. Absorption of these foods may take place through the walls of the normal vegetative mycelium which penetrates the substratum, or the task may be relegated to specialized branches or rhizoids. Many Phycomycetes show a considerable difference between the much branched mycelium within the substratum and the reproductive portion outside. Many plant parasitic fungi have specialized knoblike or finger-like organs that penetrate the host cell walls and absorb nourishment directly from the surrounding living host protoplasm. PARASITISM

IN

PLANTS

Facultative parasites of plants are frequently encountered, usually as soil saprophytes growing on the decaying roots and stems of various plants. Many of these organisms are capable of entering the living roots of host plants, where they cause wilts, root rots, and vascular infections. Most of the plant parasites can be isolated and cultivated saprophytically on nutrient media. On the other hand, many fungi are obligate parasites which have not been cultivated except on suitable living host tissues. Such obligate parasites are found among the rusts (Uredinales) and the downy mildews (Peronosporaceae). These fungi absorb their food directly from the protoplasm of the host cells by haustoria. They do not immediately kill their hosts but cause them to be weakened and dwarfed, until after spores are developed. In these instances the choice of food seems limited, for the species of fungi grow only on certain species of the hosts. There are physiological or biological forms of the stem rust of wheat, Puccinia graminis, which are similar in all morphological aspects except that one grows only on certain species or varieties while others grow only on other species or varieties. Some parasitic fungi are limited to certain genera or species of hosts, whereas other species have a very wide host range. Nonobligate plant parasites attack their hosts in different ways. Destructive parasites are fungi that kill the host cells or tissues by means of poisonous substances which diffuse into the tissues in advance of the penetrating hyphae; hence the fungus is actually obtaining its nourishment saprophytically from dead cells. A balanced parasite exemplified in many species of the Ustilaginales, is so well adapted that its demands on the host do not exceed the latter's ability to supply its needs; thus both parasite and host continue to live and develop until the fungus is ready to produce spores, and then it destroys the surrounding host tissues. Among plant parasites there are various gradations between these two extremes. Many fungi producing leaf and fruit spots are parasitic during the

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growing season, producing numerous conidia, and live saprophytically during the winter on the old, dead leaves, where many of them go through their sexual stages. T h e conidia produced during the actively growing season serve to disseminate the fungus to other healthy plants, while the sexual phase serves as an overwintering stage. T h e asexual and sexual spores of plant parasites are capable of penetrating the epidermal cells of their hosts to initiate an infection. It is frequently not clear how the penetrating hyphae obtain their food from their hosts. FUNGI

PARASITIC

IN

MAN

Unlike plant pathogens, no fungi are known to be obligate parasites of man. A l l the species causing mycoses in man, except Rhinosporidium seeberei and the organism causing Jorge Lobo's disease, have been cultivated on artificial media. T h e r e is considerable variation in the ease and the methods of cultivating pathogenic fungi. Some human pathogens attack only the superficial layers of the skin and/or mucous membranes, whereas others are capable of infecting deep-seated tissues as well as internal organs. A large majority of these fungi are normal soil saprophytes which are able to grow and sporulate there on a wide variety of plant and animal debris. Unlike the spores of plant pathogens, the spores producing disease in man are, with few exceptions, unable to germinate and penetrate uninjured skin. T h e exceptions are the dermatophytes, which normally have a predilection for hair, skin, and nails, and Candida albicans, which is capable of attacking water-soaked skin or mucous membranes. T h e spores causing deep-seated mycoses must either be inhaled into the lungs or be introduced into the body by contaminated splinters, thorns, or other foreign bodies producing trauma. Of the hundreds of kinds of fungus spores introduced into the human system, only about fifty species are known to cause disease. T h e factors that permit some saprophytic fungi to become pathogens while others do not are not well understood. Particular enzyme systems may permit certain fungi to adapt themselves to a new environment, whereas others are unable to do so. Many species of fungi can be isolated from sputum, mucous membranes, and the smooth skin which do not produce signs of disease. A number of opportunistic fungi are, however, capable of producing disease when through some circumstance the physical nature of the host has been altered. T h e spores of many saprophytes, when introduced into experimental animals, remain alive without germination or change for long periods of time. Most human pathogenic fungi show less host specificity than plant pathogens. Microsporum audouinii is perhaps the most specialized of all the dermatophytes; it attacks only children under the age of puberty, and causes only slight host reaction. In this respect it approaches the condition shown by some of the balanced plant parasites. Coccidioides

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immitis is more pathogenic to people w i t h dark skins. T h e nearest approach to obligate parasitism is shown by Pityrosporum ovale a n d Malassezia furfur, as these organisms are isolated only f r o m man. T h e y may be cultured o n artificial media w h e n supplied w i t h the proper g r o w t h factors. T h e y have been called the most parasitic a n d the least pathogenic of the organisms that cause disease in man. Bibliography Cantino, E. C., and G. F. Turian. 1959. Physiology and development of lower fungi (Phycomycetes). Ann. Rev. Microbiol., 13:97-124. Cochrane, V. W. 1958. T h e physiology of fungi. New York: John Wiley & Sons. Conant, N. F. 1937. The occurrence of a human pathogenic fungus as a saprophyte in nature. Mycologia, 29:597-598. Conant, N. F., and R. A. Vogel. 1954. T h e parasitic growth phase of Coccidioides immitis in culture. Mycologia, 46:157-164. Dickinson, S. 1949. Studies on the physiology of obligate parasitism. IV. The formation on membranes of haustoria by rust hyphae and powdery mildew germ tubes. Ann. Botany, n.s., 13:345-353. Hawkes, Lillian E. 1950. Physiology of fungi. London: University of London Press. Lilly, V. G., and H. L. Barnett. 1951. Physiology of the fungi. New York: McGrawHill. Robbins, W. J., and Roberta Ma. 1945. Growth factors for Trichophyton menlagrophytes. Amer. J. Botany, 32:509-532.

27

Variation, pleomorphism, and dimorphism in pathogenic fungi

INTRINSIC VARIATION UNIFORM CONDITIONS

UNDER

are subject to variation in their morphology and physiology. One of the greatest difficulties encountered by the taxonomic mycologist and the worker on the physiology of fungi is the amount of individual variation shown by some species. Cultures of the same organism on the same medium frequently show variations in color, surface pattern, texture, or rate of growth of the colony. These obvious changes are often accompanied by microscopic changes in amount of sporulation, spore size, and a variety of other characteristics, as well as in biochemical activities. If sufficient measurement of these characteristics is made, they may usually be fitted to the curve of normal distribution of variation within a population, and the mean value of the degree of variation for the particular isolate may be estimated by statistical analysis. Such intrinsic variation increases the difficulties in the classification of fungi. T h e fact that different isolates of the same fungus may show such obvious difA L L LIVING ORGANISMS

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ference that they were classified as distinct species led to the multiplicity of specific names for a number of dermatophytes. Careful study of single-spore cultures of a number of isolates shows that each isolate may have a range of variation sufficient to overlap the ranges shown by other isolates. In her studies of Trichophyton tonsurans Dr. L. K. Georg (1956) has shown that this species exhibits perhaps the greatest amount of variation, both in colonial characteristics and in microscopic morphology, of any of the dermatophyte species, and has been described under numerous names. In general, many of the names given describe the gross characteristics of the fungus colonies. Her studies of multiple singlespore cultures of thirteen recent isolations and twelve named species have shown a varied morphological picture with regard to both colony form and microscopic structures. Serial transfers of these cultures over a twoyear period indicate, however, that none of these characteristics are stable and that they occur at random among the isolates. All the cultures studied were considered as unstable morphological variants of a single species. Nutritional studies reveal a close similarity among these strains. As a result of these studies and a critical review of the literature, forty-three specific names have been compiled as synonyms of T. tonsurans. REVERSIBLE VARIATIONS TO E N V I R O N M E N T

IN

RESPONSE

A fungus may show wide differences in morphology, growth rate, and colony characteristics when cultivated under different environmental conditions. Inocula taken from cultures known to have come from a singlespore isolate, and grown under different environmental conditions, produce strikingly different colonies. When inocula taken from these colonies are returned to normal media under the same original uniform conditions, they form colonies closely resembling the initial strain. When cultures have been under unfavorable growth conditions for an extended time, there is sometimes a lag period which may extend over several transfers before reversion to the parent type is complete. IRREVERSIBLE

VARIATIONS

Many variations which occur in morphological and physiological characters are not obviously related to changes in the environment and are not reversible. Although these changes are most readily seen in artificial culture, there is evidence that they also take place in nature. They may originate in a number of ways: for example, by hybridization, heterokaryosis, or mutation. As the majority of pathogenic fungi belong to the Fungi Imperfecti and have no sexual reproduction, hybridization need not be considered. Beginning with the recent pioneering studies of Pontecorvo

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et al. (1953), several investigators have demonstrated a previously unsuspected mechanism whereby genetic recombinations may occur in asexual fungi. Fusion of hyphae is known to occur frequently in many of the dermatophytes, and it has been assumed that two genetically different nuclei could fuse and produce recombinant nuclei after meiosis. T h i s process, known as parasexuality, may result in permanent variants. T h e larger number of irreversible variants are mutants. These mutants are usually observed in fungus cultures as sectors in giant colonies which differ in color, texture, or degree of sporulation. Such sectors represent growth from a fungus cell that has undergone a transformation. As the colony enlarges, the growth from this cell differs in appearance from that from other cells at the periphery of the colony. Physiological as well as morphological variants are frequent in many organisms. In some genera and species mutations occur frequently, whereas they are rarely observed in other genera and species. It has been possible to induce permanent variations in fungi by the action of external agents. Many physiological variants have been produced by the actions of X rays, by the use of ultraviolet light, and by various poisons. Many of the variants so produced are similar to those observed to occur spontaneously, as reported by Emmons and Hollander

0939)PLEOMORPHISM One particular type of mutation is commonly found in many species of dermatophytes which have been in cultivation for a long time at room temperature. T h i s type of mutation is called, improperly, "pleomorphism," a term first used by De Bary to designate certain growth forms regularly observed in the life history of the rust fungi, phenomena quite distinct from the mutation in the dermatophytes. Pleomorphism or woolly degeneration, as applied to these fungi, refers to the sudden appearance upon the surface of a colony of numerous white tufts of aerial hyphae growing over the original mycelium. These tufts increase in size and coalesce to form a single mass of fluffy or woolly sterile mycelium. W h e n mass transfers of hyphae are made from the tufts to a fresh medium, the resultant colony is morphologically different from the parent colony from which it arose. Parent colonies are usually pigmented and granular or powdery, with numerous microconidia and few to many macroconidia, whereas the mutant colonies are without pigment and are sterile. In some instances a few microconidia are formed, but no macroconidia, and after a few transfers the colonies become completely sterile. Bistis (1959) came to the conclusion that the mutant arises from a change occurring in the apical cells of a growing tip which enables the mutant to grow among and over the mycelium of the parent:

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Medical mycology The two most striking properties all members of this group have in common are reduction in conidium number and an ability to grow in areas already occupied by the parent mycelium. There is wide variation among these mutants in conidium production, such that a whole spectrum of types is found, ranging from those which quite closely resemble the parent strain to the highly pleomorphic type which produces few or no conidia. All efforts, admittedly of a preliminary character, to demonstrate that these mutants are autoinduced and in some way related to the age of the parent cell or colony have led to failure or inconclusive results. No data have been found which are incompatible with application to this phenomenon of the concepts of spontaneous mutation plus positive selection.

In some recent studies of the sexual stages of the Microsporum gypseum complex and Keratinomyces ajelloi it has been observed that quite often one of the mating strains becomes pleomorphic. Once it has done so it no longer produces macroconidia, nor will it function in the production of asci when mated with the original compatible strain. DIMORPHISM The term "dimorphism" has been applied to certain pathogenic fungi which have two distinct morphological forms: a parasitic form that exists in tissues of a host and a saprophytic form that occurs in nature or on ordinary media at room temperature. Because of the significance of this phenomenon, the following brief summary of the morphological events that occur as dimorphic pathogenic fungi convert from one phase to another is outlined. Coccidioides immitis.—When young spherules or endospores of the pathogenic phase are placed on Sabouraud's agar they germinate by putting out several germ tubes which elongate into normal septate hyphae. After a week's growth at room temperature, chains of barrel-shaped arthrospores are formed on specialized branches or from the vegetative mycelium. When the arthrospores are injected into an animal they round up and are transformed into the parasitic form of the fungus. Each rounded-up spore increases in size and becomes a multinucleate spherule. When the spherule reaches maturity the protoplast is divided by cleavage planes into a number of segments, which round up and become endospores. The endospores, released by the disintegration of the spherule wall, are dispersed to new locations where they enlarge into new spherules (fig. 24). Histoplasma capsulatum.—When the parasitic yeastlike cells are placed on Sabouraud's agar at room temperature they germinate by putting out two or three germ tubes which are filled with a granular cytoplasm. The germ tubes elongate into branching septate hyphae, giving rise to a white fluffy colony. Two types of spores are produced on the mycelium: large,

Variation, Pleomorphism, dimorphism

PARASITIC FORM

301

SAPROPHYTIC FORM

thick-walled, tuberculate macroaleuriospores, and small, thin-walled microaleuriospores. In the parasitic phase of the fungus, small blastospores are found most commonly as intracellular parasites of the reticuloendothelial system. The conversion of the saprophytic to the parasitic stage has never been adequately studied in infected tissue. Many observations have been made on the sequence of morphologic events which occur in in vitro cultures, using various types of media. The series of observations by Pine and Webster (1962) present the most complete and lucid description of the manner in which mycelial elements of H. capsulatum transform to the pathogenic form of growth. These authors have described three processes by which hyphae form yeast cells: (1) moniliform chain formation; (2) direct budding; or (3) a process resembling conidial formation with subsequent budding of the spore produced. The microconidia (microaleuriospores) may form buds and the yeast phase may arise, wholly or in part, by this mechanism. The latter

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PARASITIC FORM

SAPROPHYTIC FORM

Fig. 25. Dimorphism in Histoplasma capsulatum. method seems the most logical for pulmonary infections in man. It is doubtful that the tuberculate macroconidia play any part in human infections (fig. 25). Blastomyces (Chrysosporium) dermatitidis.—When blastospores of B. dermatitidis from a biopsy section or from pus are allowed to germinate on an agar surface at room temperature, they put out a single large germ tube which develops by elongation and septation into normal saprophytic hyphae. W h e n the cultures are mature, oval to spherical aleuriospores 3 to 4 microns in diameter are produced laterally on short conidiophores. These aleuriospores are shed only by the disintegration of the stalk cell. Howard and Herndon (i960), after studying the conversion of B. titidis in tissue culture, summarized events as follows:

derma-

Variation, Pleomorphism, dimorphism

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303

SAPROPHYTIC FORM

Fig. 26. Dimorphism in Blastomyces (Chrysosporium) dermatitidis.

T h e cytoplasm of the hyphal fragments of the fungus becomes condensed into a series of packets which resemble a chain of arthrospores. These packets were most often separated from one another by clear spaces. T h e chains fragmented into individual elements, which continued to multiply by budding. Aleuriospores of B. dermatitidis germinated in the tissue cultures and changes in the germ tubes, like those described for hyphal fragments, resulted in blastospore formation. These authors never observed the aleuriospores to undergo direct conversion to blastospores. With different media, the aleuriospores have been observed to bud and develop the yeast phase (fig. 26). Sporotrichum schenckii.—When the pathogenic yeast forms from rat testes are smeared over a moist agar surface they soon begin to elongate.

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As no germ tubes are produced by the germinating yeast cells, growth is simply by elongation, which continues until the cells are six to ten times the original length before septa are formed. Many buds are formed on the growing tips and sides of the elongating cells which resemble those seen in the tissue phase. Soon after septation occurs, a branching hyphal system develops with ovate conidia borne on short sterigmata along the sides of the mycelium and on the tips of short lateral conidiophores. When inoculated into experimental animals, the conidia have been observed to elongate into cigar-shaped cells which bud at the tip. In his studies of the transformation of S. schenckii in tissue culture, Howard (1961) failed to observe direct budding of the conidia. Here blastospore formation resulted from changes that took place in hyphal elements formed by germinating conidia. Two different morphological transformations were described: (1) the formation of budding, club-shaped structures at tips of hyphae or lateral branches; and (2) the formation and fragmentation of chains of arthrospores (fig. 27). Emmonsia (Chrysosporium) parua and variety crescens.—The parasitic phase observed in the tissues of naturally infected animals consists of large thick-walled spherical cells recently given the name of adiaspores (Emmons and Jellison, i960). When germinated on solid media, the adiaspores produce many fine radiating hyphae which develop a white fluffy colony. Small spherical or ovate aleuriospores with thin, often echinulate, cell walls are developed on short lateral conidiophores. Occasionally two or three spores may be seen in chains. When these aleuriospores are injected into animals or placed in in vitro cultures at 37-42 0 C, they do not germinate with a germ tube but enlarge to form the adiaspores (fig. 27). Many methods have been advanced for conversion of the saprophytic to the pathogenic form of dimorphic fungi. Pine (Pine and Webster, 1962) has resolved the many physical and nutritional factors which affect the in vitro conversion of dimorphic fungi into four categories: (1) carbon dioxide; (2) sulfhydryl or sulfur compounds; (3) metal ions or chelating complexes; and (4) temperature. The relative importance of factors in the first three categories varies considerably with different species of fungi. The temperature factor, however, has been observed to be critical for the in vitro conversion of all the species considered.

Variation, Pleomorphism, dimorphism

PARASITIC FORM

305

SAPROPHYTIC FORM

Fig. 27. Dimorphism in (A) Emmonsia (Chrysosporium) (Haplosporangium) parva and (Ii) Sporotrichum schenckii.

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Bibliography Barnes, B. B. 1935. Induced variation. Trans. Brit. Mycol. Soc., 20:17. Bistis, G. N. 1959. Pleomorphism in the dermatophytes. Mycologia, 51:440-452. Blakeslee, A. F. 1904. Sexual reproduction in the Mucorineae. Proc. Amer. Acad. Arts Sei., 40:205-319. Brown, W. 1926. Studies on the genus Fusarium. IV. On the occurrence of saltations. Ann. Botany, 40:223-243. Campbell, C. C. 1947. Reverting Histoplasma capsulatum to the yeast phase. J . Bacteriol., 54:263-264. Conant, N. F. 1941. A cultural study of the life cycle of Histoplasma capsulatum, Darling (1906). J . Bacteriol., 41:563-578. Converse, J . L. 1955. Growth of spherules of Coccidioides immitis in a chemically defined liquid medium. Proc. Soc. Exptl. Biol. Med., 90:709-711. . 1956. Effect of physico-chemical environment on spherulation of Coccidioides immitis in a chemically defined medium. J . Bacteriol., 72:784-792. Dalldorf, Gilbert. 1962. Fungi and fungous diseases. Springfield, 111.: Charles C Thomas. Emmons, C. W. 1932. Pleomorphism and variation in the dermatophytes. Arch. Dermatol. Syphil., 25:987-1001. Emmons, C. W., and A. Hollander. 1939. T h e action of ultraviolet radiation on dermatophytes. I I . Mutations induced in cultures of dermatophytes by exposure of spores to monochromatic ultraviolet radiation. Amer. J . Botany, 26:467. George, B. S., and O. A. Plunkett. 1948. Dissociation in Candida albicans. J . Invest. Dermatol., 10:327. Howard, D. H. 1961. Dimorphism of Sporotrichum schenckii. J . Bacteriol., 80:522-527. . 1962. T h e morphogenesis of the parasitic forms of dimorphic fungi. Mycopathologia, 18:127-139. Howard, D. H., and Roy L. Herndon. i960. Observations on tissue cultures of mouse peritoneal exudates with Histoplasma capsulatum. J . Bacteriol., 78:69-78. Larsh, H. W., A. Hinton, and S. L. Silberg. 1956. Conversion and maintenance of Histoplasma capsulatum in tissue culture. Proc. Soc. Exptl. Biol. Med., 93:612-615. Lubarsky, R., and O. A. Plunkett. 1955. In vitro production of the spherule phase of Coccidioides immitis. J . Bacteriol., 70:182-186. MacKinnon, J . E. 1940. Dissociation in Candida albicans. J . Infect. Diseases, 66:59-77. Menges, R . W., and R . T . Habermann. 1954. Isolation of Haplosporangium parvum from soil and results of experimental inoculations. Amer. J . Hyg., 60:106-116. Nickerson, W. J . 1951. Physiological basis of morphogenesis in animal disease fungi. Trans. N.Y. Acad. Sei., 2d ser., 13:140-145. . 1957. Experimental control of morphogenesis in microorganisms. Ann. N.Y. Acad. Sei., 60:50-57. Olive, L. S. 1958. On the evolution of heteiothallism in fungi. Amer. Naturalist, 42:233-251.

Variation, Pleomorphism, dimorphism

307

. 1962. Mechanisms of genetic recombinations in the fungi. In Gilbert Dalldorf, Fungi and fungous diseases. P. 126. Springfield, 111.: Charles C Thomas. Pine, L. 1957. Studies on the growth of histoplasma capsulatum. I I I . Effect of thiamine and other vitamins on the growth of the yeast and mycelial phases of Histoplasma capsulatum. J . Bacteriol., 74:239-245. . i960. Morphological and physiological characteristics of Histoplasma capsulatum. In H. C. Sweany, ed., Histoplasmosis. Pp. 40-75. Springfield, 111.: Charles C Thomas. Pine, L., and C. L. Peacock. 1958. Studies on the growth of Histoplasma capsulatum. IV. Factors influencing conversion of the mycelial phase to yeast phase. J . Bacteriol., 7 5 : 1 6 7 - 1 7 4 . Pine, L., and R . S. Webster. 1962. Conversion in strains of Histoplasma capsulatum. J . Bacteriol., 8 3 : 1 4 9 - 1 5 7 . Pontecorvo, G., J . A. Raper, L. M. Hemmons, K. D. MacDonald, and A. W. S. Bufton. 1953. T h e genetics of Aspergillus nidulans. Adv. Genet., 5 : 1 4 1 - 2 3 8 . Raper, K. B., D. F. Alexander, and R . D. Coghill. 1944. Penicillin. I I . Natural variation and penicillin production by Penicillium notatum and allied species. J . Bacteriol., 48:639-659. Robbins, W. J., and Ilda McVeigh. 1949. T h e "dual phenomenon" and Trichophyton mentagrophytes. Mycologia, 4 1 : 1 2 8 - 1 4 0 . Salvin, S. B. 1949. Phase-determining factors in Blastomyces dermatitidis. Mycologia, 4 1 : 3 1 1 - 3 1 9 . Scheer, G. H. 1957. Studies on the dimorphism of Histoplasma capsulatum. I. T h e roles of -SH group and incubator temperature. Exptl. Cell Research, 12:92-102. Tarbet, J . E., E. T . Wright, and V. D. Newcomer. 1952. Experimental coccidioidal granuloma: developmental stages of sporangia in mice. Amer. J . Pathol., 28:901-917. Weidman, F. D. 1926. Morphologic variations in ringworm species of the toes. Arch. Dermatol. Syphil., 13:374. Whitehouse, H. L. K. 1949. Heterothallism and sex in the fungi. Biol. Rev. Cambridge Philos. Soc., 24:411-447. Wilhelm, Stephan. 1947. T h e dual phenomenon in the dermatophytes. Mycologia, 39:716-724.

28 Classification of fungi

of known fungi in existence today, only about fifty pathogenic species must be differentiated. Positive identification of the species of a few forms are made by examination of clinical or histological specimens. Most frequently, specific identification must be made by a thorough study of the gross and microscopic morphology of the fungus as it develops on a specified medium under controlled environmental conditions. T h e characteristics used in the classification of fungi are gross morphology of culture, nature of the hyphae, types of fruiting bodies, and nature and development of asexual and sexual spores. As noted in chapter 27, fungi are variable in nature, and this variability must always be taken into consideration in the naming of new species. OF THE THOUSANDS

T h e classification of a group of organisms as large and diverse as the fungi presents numerous difficulties because of differences of opinion among mycologists as to the weight and significance of certain factors as taxonomic criteria. Such differences arise mainly from incomplete knowledge of the structure, development, and physiology of the fungi. As our

308

Classification of fungi

309

knowledge increases and we learn new facts about the fungi, it often becomes necessary to alter our concept of their relationships. This change of concept may require a reclassification and a change of name. T h e purpose of any system of classification is to arrange organisms according to an internationally accepted system which shows the relationship of fungi to one another and to other living organisms, and to give them names that distinguish them from other similar organisms. T h e old phylum Thallophyta, which included both algae and fungi, has been discarded. T h e algae are now classified under a number of divisions. Bacteria, fungi, and slime molds have been placed in separate divisions: bacteria and actinomycetes in Schizomycophyta; slime molds in Myxomycophyta; and fungi in Eumycophyta. T h e categories used in the classification of fungi are kingdom, division, class, order, family, genus, and species. T h e kingdom is the largest of the categories and includes many divisions, each division may include many classes, and so on down to the species, which is the unit of classification. Some of these categories may be divided into subgroups. T h e name of an organism is a binomial composed of two words. T h e first name designates the genus, and the second, the species. A generic name is always written with an initial capital. T h e specific epithet is usually an adjective in Latin form, which must agree in gender with the generic name; or it may be the genitive case of a noun, or a noun in the nominative case. Species names are not capitalized. Binomials should be underlined when written and italicized when printed. T h e abbreviated name of the mycologist who first described the species usually follows the binomial. If a species is changed to another genus the first author's name is placed in parenthesis and the name following the parenthesis is that of the author responsible for the change. T h e year of publication of the description is frequently placed after the author's name following the binomial. T h e following is an example of the use of the taxonomic categories in classifying the important pathogenic fungus, Histoplasma capsulatum Darling 1906. Kingdom Division Class Order Family Section Tribe Genus Species

Plant Eumycophyta Deuteromycetes (Fungi Imperfecti) Moniliales Moniliaceae Amerosporae Aleuriosporeae Histoplasma capsulatum

T h e division Eumycophyta is made up of four large classes, Phycomycetes, Ascomycetes, Basidiomycetes, and Deuteromycetes (Fungi Imper-

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Medical mycology

fecti). In recent years some of the categories recognized as subclasses have been given class status. In differentiating among these classes, particular attention is paid to methods of sexual reproduction (see chap. 27). Phycomycetes.—This class is characterized by an abundant, manybranched, nonseptate, multinucleate tubular mycelium. Septae are usually formed in the mycelium only when sporangia or sex organs are developed. T h e formation of sexual oospores and zygospores and asexual spores in sporangia by cleavage planes is the most significant criterion in defining the Phycomycetes. Ascomycetes.—The mycelium is usually abundant and septate, but may be reduced to a single budding cell or chains of budding cells, as in the true yeasts. Sex organs are not readily observed in most species but, as the result of a sexual process, sexual spores are formed in a spore mother cell, the ascus, by free cell formation. T h e only parasitic species of animals and man are found in the Eurotiales and Myriangiales. Many types of asexual spores are formed by the Ascomycetes. Basidiomycetes.—The Basidiomycetes are fungi in which the sexual spores are borne externally on special club-shaped spore mother cells, called basidia. T h e primary mycelium developing from a germinating spore has uninucleate cells; however, two hyphae soon fuse and the secondary mycelium becomes binucleate. Thus the vegetative mycelium making up the sporocarp, or fruiting body, of a basidiomycete such as a mushroom or puffball, is composed of binucleate cells with frequent "clamp connections" between the cells. Clamp connections are found only on basidiomycete mycelium, but their absence does not exclude the organism. T h e basidia are usually produced on the surface of the basidiocarp in a hymenial layer. T h e young basidium, like the young ascus of the Ascomycetes, is at first binucleate. T h e nuclei fuse to form a zygote nucleus which undergoes meiosis, producing four nuclei which are extruded through thin sterigmata into the developing basidiospores outside the basidium. T h e Basidiomycetes possess the largest fruiting bodies of all the fungi. Many species of the orders Agaricales and Lycoperdales are edible, some are poisonous, and some are allergens. Members of the orders Uredinales and Ustilaginales, known as the rust and smut fungi, respectively, produce serious plant diseases, and some are important as allergens. With the exception of species of Ustilago, which are frequently isolated from sputum, Basidiomycetes are rarely encountered in cultures. Deuteromycetes (Fungi Imperfecti).—Either the fungi included in this class have no form of sexual reproduction, or the sexual stage is unknown. Many of these fungi possess asexual spore forms similar to those of known Ascomycetes, and further studies may prove many of them to possess a perfect form. When the perfect stage is discovered the fungus assumes the generic name of the ascomycete. In some instances, as in the genera Aspergillus and Penicillium, only a small percentage of the species are

312

Medical mycology

known to have perfect forms, and these belong to several genera. T h e sexual stages of many organisms do not form sexual spores under normal cultural conditions. For this reason mycologists find it more convenient to use "Imperfecti" generic names for some fungi known to have a perfect stage. As the classification of the Fungi Imperfecti is based on the characteristics of the asexual stages, it is an entirely artificial system, and the fact that two species are placed in the same genus does not necessarily mean they are closely related. T h e fact that an organism may produce more than one type of asexual spore presents complex taxonomic problems; whenever possible, the dominant spore type is used as the taxonomic character in keys to classification. Most of the fungi pathogenic to man, and those most frequently encountered as contaminants in cultures, belong in the order Moniliales of the Fungi Imperfecti. T h e controversial actinomycete genera, Actinomyces, Nocardia, and Streptomyces, are included in this order for convenience. Microbiologists consider them to belong to the Schizomycophyta. As they have a branching mycelium with apical growth and reproduce by arthrospores and conidia, and their infections are considered with other mycotic infections, it is more convenient to fit them into the old scheme of classification.

Bibliography Barnett, H. L. i960. Illustrated genera of imperfect fungi. Minneapolis: Burgess Publishing Co. Benjamin, R . K. 1956. A new genus of the Gymnoascaceae with a review of the other genera. El Aliso, 3:301-328. . 1959. T h e merosporangiferous Mucorales. El Aliso, 4:321-453. Cifferri, R. i960. Manuale de micologia medica. Vols. I, II. Pavia: Casa Editrice Renzo Cortina. Ciferri, R., et al. 1956. A revision of the Paracoccidioidaceae family in the light of recent knowledge. Inst. Mycol. Univ. Recife, Publ. 54. Clements, F. E., and C. L. Shear. 1931. T h e genera of fungi. New York: H. W . Wilson Co. Coker, W. C. 1923. T h e Saprolegniaceae, with notes on other water molds. Chapel Hill: University of North Carolina Press. Cummins, C. S., and H. Harris. 1958. Studies on the cell wall composition and taxonomy of Actinomycetales and related groups. J. Gen. Microbiol., 18:173189. Engler, A., and K. Prantl. 1897-1900. Die natürlichen Pflanzenfamilien. Vol. I, Pts. I, II. Leipzig: William Engelmann. Fitzpatrick, H. M. 1930. T h e lower fungi: Phycomycetes. New York: McGrawHill. Gilman, J. C. 1945. A manual of soil fungi. 2d ed., 1957. Ames: Iowa State University Press.

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313

Hesseltine, C. W. 1952. A survey of the Mucorales. Trans. N.Y. Acad. Sei., 2d ser., 14:210-214. . 1955. Genera of Mucorales with notes on their synonymy. Mycologia, 47:344-363. Hughes, S. J. 1953. Conidiophores, conidia, and classification. Canad. J. Botany, 3i:577-659Langeron, M. 1945. Precis de micologie. Paris: Masson. Lanjouw, J., ed. 1956. International code of botanical nomenclature. Regnum Vegetable, 8:1-338. Lodder, J., and N. J. W. Kreger-van Rij. 1952. T h e yeasts: a taxonomic study. Amsterdam: North-Holland Publishing Co. Martin, G. W. 1936. A key to the families of fungi exclusive of the lichens. Univ. Iowa Studies Nat. Hist., 17:83-115. . 1961. Key to the families of fungi. In G. C. Ainsworth, A dictionary of the fungi. Pp. 497-519. Kew, Surrey: Commonwealth Mycological Institute. Raper, K. B., C. Thom, and D. I. Fennel. 1949. A manual of the penicillia. Rev. ed. Baltimore: Williams & Wilkins Co. Saccardo, P. A. 1882-1931. Sylloge fungorum omnium hucusque cognitorum. Pavia: privately printed. 25 vols. Seaver, F. J. 1942. T h e North American cup-fungi (Operculates). New York: privately printed. Skinner, C. E., C. W. Emmons, and H. M. Tsuchiya, revisers. 1947. Molds, yeasts, and actinomycetes, by A. T . Henrici. 2d ed. New York: John Wiley & Sons. Sparrow, F. K. 1950. T h e expanding horizons of mycology. Mycologia, 42:683-692. . i960. Aquatic Phycomycetes. Ann Arbor: University of Michigan Press. Thom, C., and K. B. Raper. 1945. A manual of the Aspergilli. Baltimore: Williams & Wilkins Co. Vuillemin, P. 1911. Les aleuriospores. Bull. Soc. Sei. Nancy, 3d ser., 12:151-175. Zycha, H. 1935. Mucorinae. In Kryptog. der Mark Brandenburg, 6a: 1-264. Leipzig: Gebrüder Borntraeger.

2 9

Identification of fungi of importance in medical mycology

IN THE CLASSIFICATION shown in figure 28, an attempt has been made to place the fungi pathogenic to man, as well as the common contaminants, in the framework of systematic mycology. T h e purpose of the following key is to differentiate and to show the relationships among these organisms. T h e numbers accompanying generic names in the key are numbers assigned to the genera as described later. T h e morphological descriptions of the genera and species are based on their growth on Sabouraud's glucose agar.

EUMYCOPHYTA Fungi producing an abundant, branched, nonseptate, multinucleate, tubular mycelium; usually septa or cross walls are formed in the mycelium only when sporebearing bodies or sex organs are formed, or when the mycelium is very old. Sexual reproduction, when it occurs, is by means of gametes, or of gametangia giving rise to resting oospores and zygospores. T h e most 314

Fungi of importance in medical mycology

315

characteristic feature of many of the Phycomycetes is the formation of asexual spores in sporangia by cleavage CLASS PHYCOMYCETES Asexual reproduction by zoospores or detached zoosporangia; perfect stage represented by oospores produced by fusion of unlike gametangia without differentiated gametes or, less commonly, by fusion of differentiated gametes

SUBCLASS OOMYCETES ( n o r e p r e s e n t a t i v e s )

Asexual reproduction by sporangiospores, by modified sporangial segments functioning as conidia, or by true conidia; gametangia morphologically similar; perfect stage represented by zygospores. SUBCLASS Z Y G O M Y C E T E S

Asexual reproduction by modified sporangia functioning as conidia or by conidia that are forcibly discharged. Parasitic on lower animals and insects. Isolates show little aerial mycelium ORDER ENTOMOPHTHORALES Sporangium modified to function as a single conidium forcibly discharged at maturity. Mycelium persistent, of uninucleate cells; saprobic on dung or in humus

O n e species is p a t h o g e n i c

FAMILY

BASIDIOBOLACEAE

BASIDIOBOLUS RANARUM (2)

Mycelium usually breaking u p into multinucleate segments. Usually parasitic on insects; occasionally saprophytic. FAMILY

ENTOMOPHTHORACEAE

Entomophthora coronata is reported as the causal organism of a phycomycosis of horses. N o t discussed here. Asexual reproduction typically by nonmotile sporangiospores (aplanospores) sometimes borne in merosporangia or sporangioles; sometimes by conidia which appear to be modified sporangioles. Chiefly saprobic; a few endoparasitic in man but not on insects. Isolates usually rapidly growing, filling the culture chamber with aerial mycelium. ORDER M U C O R A L E S

Sporangia all columellate and more or less alike; sporangial membrane thin, fugaceous; sporangiospores liberated by breaking u p of sporangial wall

FAMILY MUCORACEAE

Stolons present. Sporangia spherical to pyriform and always with a definite hypophysis; sporangiophores simple, usually borne on arcs of stolons but typically not opposite rhizoids ABSIDIA (3) Sporangia spherical, without hypophysis, on upright, simple sporangiophores arising from stolons opposite rhizoids RHIZOPUS (4) Stolons absent. Sporangiophores variously branched or simple; sporangia terminal, not borne circinately MUCOR (5) Sporangiophores branched with all branches bearing sporangia circinately

CIRCINELLA (6)

Columellate sporangia absent, merosporangia (cylindrical sporangioles) or conidia always present. Merosporangia cylindrical, containing 5 to 20 sporangiospores borne directly over entire surface of a terminal vesicle. F A M I L Y SYNCEPHALASTRACEAE

Only one genus treated

SYNCEPHALASTRUM (7)

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Medical mycology

Sporangia and merosporangia absent, conidia developed on sterigmata over entire surface of a terminal vesicle F A M I L Y C U N N I N G H A M E L L A C E A E Only one genus treated C U N N I N G H A M E L L A (8) Branching, septate mycelium abundant, occasionally reduced to single cells or chains of budding cells. Diagnostic characteristic of this class is presence of a spore mother cell, the ascus, produced as a result of a sexual fusion of nuclei; ascospores are developed in ascus by free cell formation following meiosis CLASS ASCOMYCETES Asci borne singly without ascocarp or in clusters at different levels in loose or closed ascocarp SUBCLASS PLECTOMYCETES No ascocarp formed, zygote a single diploid cell transformed directly into an ascus; mycelium sometimes lacking ORDER ENDOMYCETALES Mycelium scanty or lacking; reproduction mainly by budding; ascosporic yeasts F A M I L Y SACCHAROMYCETACEAE Only one genus treated S A C C H A R O M Y C E S (9) Ascocarp a cleistothecium; asci scattered and evanescent within cleistothecium. Peridium absent or composed of lax network of hyphae, or of closely interwoven hyphae usually forming a pseudoparenchymous covering. ORDER EUROTIALES

Peridium, when present, a lax network of vegetative and specialized hyphae making up loosely woven cleistothecium, with or without characteristic peridial appendages of various sorts, containing numerous scattered evanescent asci FAMILY GYMNOASCACEAE Peridial hyphae loosely reticulate, thick-walled, with many pointed, spinelike or hooked, short, free apices GYMNOASCUS (10) Peridial hyphae, compact, branched, and anastomosing, ending in thick-walled, dumbbell-shaped cells or elongated spiral appendages. ARTHRODERMA ( 1 1 )

Peridial hyphae verticillately branched, asperulate, hyaline, with numerous free ends, either blunt or elongated and tapering or coiled. NANNIZZIA ( 1 2 )

Cleistothecia and peridial hyphae dark-colored. Peridial hyphae branched, thick-walled, septate, smooth, ending in short septate spines or elongated appendages MYXOTRICHUM ( 1 3 ) Cleistothecia fully formed, usually very small, globose or knotlike, as a rule sessile, with a thin, dark, carbonaceous, or membranous to fleshy, often pseudoparenchymatic peridium, which remains closed at maturity, then breaks up irregularly, seldom opening by a mouth or regular fracture. Asci irregularly crowded in cleistothecia, globose to pearshaped, 2- to 8-spored. Spores one- to many-celled. Conidia of widely varying form F A M I L Y EUROTIACEAE Cleistothecia with definite wall of thin-walled cells one layer thick. ALLESCHERIA ( 1 4 )

Cleistothecia of several layers of interwoven hyphae. Perfect stages of Aspergillus, Eurotium, Sartorya, and Emericella. Perfect stages of Penicillium, Taloramyces, and Carpenteles. Not treated. Ascocarp a perithecium or a uniloculate stroma resembling a perithecium in which asci are arranged in parallel series . . S U B C L A S S P Y R E N O M Y C E T E S

Fungi of importance in medical mycology

317

This subclass is made up of a large number of orders and families, of which only three genera are treated. Perithecia superficial, membranous, bearing conspicuous appendages on body or beak; paraphyses lacking; asci deliquescing before maturity of the 1-celled dark ascospores C H A E T O M I U M (15) Ascocarp a unilocular stroma resembling a perithecium; asci broadly club-shaped without paraphyses; ascospores muriform. PLEOSPORA (16) Asci borne at different levels in locules of dark stroma surrounding hair shaft. Does not fruit in culture PIEDRAIA (17) Fungi in which sexual reproduction is absent or unknown. Asexual reproduction by various spore forms. D E U T E R O M Y C E T E S (Fungi Imperfecti) Conidia borne in closed fruit bodies (pycnidia). ORDER SPHAEROPSIDALES

Conidia borne in open fruit bodies (ascervuli) ORDER M E L A N C O N I A L E S Yeastlike fungi with or without pseudomycelium or true mycelium, reproducing by blastospores ORDER PSEUDOSACCHAROMYCETALES Conidia borne free on mycelium or conidiophores. . ORDER M O N I L I A L E S Mycelium only, no reproductive spores formed M Y C E L I A STERILIA ORDER SPHAEROPSIDIALES

Pycnidia more or less globose, walls dark, tough, leathery or carbonaceous. F A M I L Y SPHAEROPSIDACEAE

One genus treated P H O M A (18) Pycnidia globose or flattened, walls bright-colored, fleshy or waxy. FAMILY ZYTHIACEAE

One genus treated

PLENOZYTHIA

(19)

ORDER M E L A N C O N I A L E S

No representatives. ORDER PSEUDOSACCHAROMYCETALES

Reduced true mycelium or no mycelium; pseudomycelium may be formed; budding cells are always present; arthrospores may be formed; no true conidia; cells are hyaline, never dark or brown; carotenoid pigment may be produced FAMILY CRYPTOCOCCACEAE Unicellular budding cells without carotenoid pigments. SUBFAMILY CRYPTOCOCCOIDEAE

Reproduction by blastospores that are pinched off from mother cell. Cells surrounded by capsule in which starchlike polysaccharide is formed CRYPTOCOCCUS (20) Usually no capsule formation; no starchlike polysaccharide produced. TORULOPSIS ( 2 1 )

Reproduction by blastospores accompanied by short hyphal filaments. MALASSEZIA ( 2 3 )

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Reproduction by polar budding; buds separated from mother cell by septation PITYROSPORUM (22) Unicellular budding forms that may produce pseudomycelium; yellow to red color owing to presence of carotenoid pigment. S U B F A M I L Y RHODOTORULOIDEAE

One genus RHODOTORULA (24) Unicellular forms reproducing by blastospores; both pseudomycelium and mycelium may be formed S U B F A M I L Y CANDIDOIDEAE One genus CANDIDA (25) Mycelium and pseudomycelium formed; reproduction by arthrospores and blastospores S U B F A M I L Y TRICHOSPOROIDEAE One genus TRICHOSPORON (26)

ORDER M O N I L I A L E S

Mycelium, conidiophores, and conidia hyaline or bright-colored. F A M I L Y MONILIACEAE

Hyphae, conidiophores, and conidia dark-colored. F A M I L Y D E M A T I A C E A E Fruiting hyphae united to form coremium F A M I L Y STILBACEAE Fruiting hyphae united to form tubercle or sporodochium. F A M I L Y TUBERCULARIACEAE

T h e genera of the families of the Moniliales are frequently separated into sections on basis of shape, color, and septation of conidia. Conidia i-celled AMEROSPORAE Conidia 2-celled DIDYMOSPORAE Conidia with 3 or more cells PHRAGMOSPORAE Conidia of two kinds: i-celled microconidia and macroconidia with 3 or more cells TRICHOPHYTONAE Conidia muriform DICTYOSPORAE

T R I B E S OF M O N I L I A C E A E A M E R O S P O R A E

Hyphae very short or obsolete, little different from conidial chains; spores intermediate between true conidia and arthrospores OOSPOREAE Hyphae elongate and distinct from conidia. Conidiophores and hyphae breaking up into arthrospores. ARTHROSPOREAE

Conidiophores simple or little branched or apically swollen; conidia in heads. Conidia not in chains CEPHALOSPOREAE Conidia in chains ASPERGILLEAE Conidiophores much branched; conidia not in heads. Conidia borne on verticillately branched conidiophores. VERTICILLEAE

Conidia borne irregularly on simple or branched but not inflated or verticillately branched conidiophores; conidia freely abstricted from conidiophores BOTRYTIDEAE

Rhizopus

Absidia

Mue or

Cunninghamella

Haplosporangium parvum

Syncephalaslrum

Circinella

Piedraia h or tai

Coccidioides immitis

Saeeharomyces

Ar ihroder ma

Gymnoascus

PLATE 45. Colonies of Phycomycetes and Plectomycetes. Genera nos. 3, 4, 5, 6, 7, 8, 9, 10, i l , 17, 29, 4$.

46. Colonies of Pyrenomycetes: fungi producing perithecia and pycnidia and yeastlike fungi. Genera nos. 14, 15, 16, 18, 19, 20, 2 i , 23, 24. PLATE

Geotruhum versiforme

Cephalosporiutn

Trichoderrna

47. Colonies of Candidioideae, Arthrosporeae, and Cephalosporeae. Genera nos. 25, 26, 27, 28, 31, 32.

PLATE

48. Colonies of Aspergillaceae, Aspergillus, and Pénicillium. Genera nos. 34, 35. PLATE

Paecilomyces

Gliocladium

Scopulariopsis

Scopulariopsis

Rhinolrichum

Sporotrichu schenckii

Sporotrichum schenckii

Blastomyces derrnatitidis

Blastomyces derrnatitidis

Ammonium

Monosporium apiospermum

Blastomyces brasihensis

49. Colonies of Aspergillaceae, Botrytideae, and Aleuriosporeae. Genera nos. 36, 37, 38, 41, 42, 43, 45. PLATE

5 o. Colonies of Aleuriosporeae, Verticilleae, and Actinomyceteae. Genera nos. 39, 40, 44, 46, 47, 49, 50, 51. PLATE

Trichophyton mentagrophytes (fluffy)

Trichophyton rubrum (powdery)

Trichophyton mentagrophytes (powdery)

Trichophyton tonsurans (common brown form)

Trichophyton schoenleini

Trichophyton concentricum

Trichophyton violaceum

Trichophyton verrucosum (alba)

Trichophyton rubrum (fluffy)

Trichophyton tonsurans (yellow form)

Trychophyton ferrugineum

Trichophyton verrucosum (ochraceum)

51. Front and reverse of colonies of Trichophyton species. Genus no. 53.

PLATE

Trichophyton verrucosum (discoïdes)

Trichophyton terrestre

Trichophyton megnini (rosaceum)

Trichophyton equinum

Epidermophyton fioc casum

Microsporum audouini

Microsporum audouini (brown)

Microsporum canis [ S y n . , M. lanosum] ( y o u n g )

Microsporum fulvum [ S y n . , M. gypseum]

Microsporum nanum

Microsporum canis [ S y n . , M. lanosum] (old)

Keratinomyces ajelloi

PLATE 52. Front and reverse of colonies of dermatophytes. Genera nos. 52, 53, 54, 55.

Papularia

Hormodendrum pedrosoi

Phialophora verrucosa

Pullularia

Dematium

Hormodendrum ( saprophyte)

Cladosporium wernecki

Nigrospora

Acrothecium

Heterosporium

Stachybotrys

Helminthosporium

53. Colonies of Dematiaceae. Genera nos. 56, 57, 58, 59, 60, 61, 62, 63, 64, 65.

PLATE

Alternaría

Macrosporium

Stemphyllium

54. Colonies of Dematiaceae, Stilbaceae, and Tuberculariaceae. Genera nos. 66, 67, 68, 69, 70, 7 1 , 72, 73. PLATE

Fungi of importance in medical mycology

319

Conidia freed only by death of stalk cell or cells of mycelium. ALEURIOSPOREAE

Hyphae very thin, often less than

L/U

ACTINOMYCETEAE

TRIBE OOSPOREAE

Sporiferous hyphae variously branched, spores intermediate between arthrospores and conidia MONILIA (27) TRIBE ARTHROSPOREAE

Colonies pasty and yeastlike. Arthrospores derived from vegetative hyphae; no empty intercalary cells

GEOTRICHUM (28)

Colonies cottony, never yeastlike. Arthrospores developed from normal mycelium and specialized branches with empty intercalary cells; arthrospores swollen, barrel-shaped. COCCIDIOIDES ( 2 9 )

Arthrospores developed from normal vegetative hyphae; empty intercalary cells present or absent; arthrospores not swollen or barrel-shaped. GYMNOASCACEAE IMPERFECTI ( 3 0 ) TRIBE CEPHALOSPOREAE

Conidiophores simple, conidia ovate to elongate, held together in slimy head CEPHALOSPORIUM (31) Conidiophores branched, trifid, each branch bearing a slimy spore-head. TRICHODERMA ( 3 2 )

Conidiophores with swollen terminal vesicle bearing a head of conidia. OEDOCEPHALUM

(33)

TRIBE ASPERGILLEAE

Conidia borne in chains from specialized cells called phialides. Basal cell of conidiophore highly specialized; upper cell a swollen vesicle bearing one or two series of phialides ASPERGILLUS (34) Basal cell not differentiated, upper cell not swollen. Phialides flask-shaped, straight, axis usually parallel to that of metulae upon which they are borne. Chains of conidia not held together by secretion of a gel. PENICILLIUM ( 3 5 )

Chains of conidia held together by secretion of a common gel; in some species chains disappear, leaving only irregular arrangement in gel

GLIOCLADIUM ( 3 6 )

Phialides flask-shaped, with long tapering neck of flask at angle to main axis of phialide PAECILOMYCES (37) Phialides not flask-shaped but tapering gradually from base to apex; conidia with broad collar at base SCOPULARIOPSIS (38) TRIBE VERTICILLEAE

Colonies white, green, yellow, pink, or rose; conidia rarely collecting in masses at tips of branches VERTICILLIUM (39)

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Colonies deep orange to brown; conidia forming a head, held together by slime ACROSTALAGMUS (40) TRIBE BOTRYTIDEAE

Conidia borne on short sterigmata along mycelium or acrogenously on short side branches SPOROTRICHUM (41) Conidia borne singly on tips of simple conidiophores; colonies white; mycelium compact; conidiophores pointed, arising from prostrate mycelium; conidia narrowly ovate ACREMONIUM (42) Colonies smoky, gray; mycelium fluffy; conidiophores not pointed; conidia broadly ovate, dark-colored in mass MONOSPORIUM (43) Conidia borne acropleurogenously on tips of variously branched conidiophores BOTRYTIS (44) TRIBE ALEURIOSPOREAE

Spores 3 to in diameter. Spores mostly as broad as long; mycelium only at 37°C. CHRYSOSPORIum PARVUM (45); synonyms: Haplosporangium parvum, Emmonsia parua Spores pyriform; scars broad; yeastlike budding cells developed at 37°C on enriched media. CHRYSOSPORIUM DERMATITIDIS (45); syn.: Blastomyces dermatitidis Spores mostly above 15 ^ in diameter. Colonies frequently colored; spores war ted or echinulate and colored; microconidia phialospores SEPEDONIUM (46) Colonies white, spores hyaline; smooth-walled microaleuriospores and tuberculate macroaleuriospores HISTOPLASMA (47) TRIBE ACTINOMYCETEAE

Vegetative mycelium fragmenting into bacillary or coccoid elements. Anaerobic or microaerophilic, not acid-fast ACTINOMYCES (48) Aerobic, partly acid-fast or not acid-fast NOCARDIA (49) Vegetative mycelium not fragmenting into bacillary or coccoid elements. Spores formed in chains, frequently in spirals STREPTOMYCES (50) M O N I L I A C E A E SECTION DIDYMOSPORAE

Conidiophores simple with apical head of 2-celled conidia. TRICHOTHECIUM ( 5 1 )

M O N I L I A C E A E SECTION TRICHOPHYTONAE

Macroconidia thin-walled. Macroconidia broad, blunt to clavate, 2- to 4-celled. EPIDERMOPHYTON ( 5 2 )

Macroconidia narrowly cylindrical with rounded ends.

TRICHOPHYTON ( 5 3 )

Fungi of importance in medical mycology

321

Macroconidia thick-walled. Macroconidia spindle-shaped to elliptical with echinulate walls. MICROSPORUM ( 5 4 )

Macroconidia long, slender with parallel walls tapering at each end; walls smooth KERATINOMYCES (55) D E M A T I A C E A E SECTION AMEROSPORAE

Young colonies pasty and yeastlike, little aerial mycelium. Mycelium thick-walled, hyaline at first, later dark, bearing ovate conidia along sides PULLULARIA (56) Mycelium dark, of rectangular thick-walled cells bearing lateral chains of globose conidia DEMATIUM (57) Colonies composed of smoky to dark mycelium, aerial mycelium abundant. Conidiophores simple. Conidiophores short; undifferentiated side branches bearing clusters of ovate conidia with longitudinal germ pore PAPULARIA (58) Conidiophores with swollen apex on which broadly ovate conidia are borne at right angles to conidiophores NIGROSPORA (59) Conidiophores in form of phialides bearing ovate conidia endogenously which accumulate in clusters at tip; other forms of Cladosporium type of sporulation may be present PHIALOPHORA (60) Conidiophores slightly swollen at apex, bearing numerous sterigmata from which conidia are abstricted; usually held together in slime head STACHYBOTRYS ( 6 1 ) Conidiophores branched. Conidia in branching chains without phialides. CLADOSPORIUM (62); syn.: Hormodendrum D E M A T I A C E A E SECTION PHRAGMOSPORAE

Conidia formed singly, either terminal or lateral, not in whorls on welldifferentiated conidiophores. Conidiophores geniculate, conidia smooth-walled. HELMINTHOSPORIUM ( 6 3 )

Conidiophores not geniculate, conidia with spiny walls. HETEROSPORIUM ( 6 4 )

Conidia formed in terminal whorls

ACROTHECIUM

(65)

D E M A T I A C E A E SECTION DICTYOSPORAE

Conidia borne singly on apex of simple conidiophores MACROSPORIUM (66) Conidia borne singly on tips of branched conidiophores. STEMPHYLIUM (67) Conidia in chains on simple or branched conidiophores. . ALTERNARÍA (68) STILBACEAE

Colonies white or bright-colored, mycelium and spores hyaline, coremia lax, conidia in chains from phialides ISARIA (69)

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322

Colonies dark, mycelium dark, conidia hyaline. Coremia erect, darkstalked, cylindrical to pyriform; conidia in chains from branched conidiophores; no phialides STYSANUS (70) Colonies dark, mycelium dark. Conidia borne on branched conidiophores, forming globose head at apex of stalked coremia. .. DENDROSTILBELLA ( 7 1 ) TUBERCULARIACEAE

Conidia and hyphae hyaline or bright-colored. Conidia fusiform, curved, with more than 2 cells; sporodochia cushion-shaped FUSARIUM (72) Conidia and hyphae dark-colored. Sporodochia small, punctate, with short conidiophores bearing globose, usually roughened, or reticulated conidia; conidia i-celled or divided by cross walls EPICOCCUM (73) 1. Rhinosporidium

seeberi

Wernicke.

T h i s organism has never been cultured and its complete life cycle is unknown; for this reason its proper place among the fungi has not been determined. T h e development of the organism in tissue suggests strongly that it is closely allied with holocarpic Chytridiales. In the polyps developed in the mucosa of nose, eyes, larynx, and genital organs, the organisms appear as spherical bodies 6 - 3 0 0 p in diameter. A s the spherical bodies increase in size they develop thick retractile walls and become multinucleate, and eventually the cytoplasm undergoes progressive cleavage to form numerous spores. T h e large spherules have been interpreted as sporangia, and the lobulated spores with their small dotlike contents, as spores. It appears to me from the few sections we have had the opportunity of studying that the large mature structures are sori and the contents are zoosporangia which on germination will produce zoospores. It is generally believed that infections are associated with swimming or working in stagnant water. It is quite possible that we are dealing with a parasitic or saprophytic chytridiaceous fungus. V a n Breuseghem et al. ( 1 9 5 5 ) have questioned the nature of the endospores, and have identified as spores certain bodies within them usually considered as proteinaceous spherules.

Fungi of importance in medical mycology

323

2. Basidiobolus ranarum Eidam.

Colonies on Sabouraud's agar are thin, flat, glabrous, radially folded, and yellowish, later becoming covered with a white bloom composed of thin, short, aerial hyphae. Mycelium variable, 8-20 p in diameter, with frequent septa, numerous chlamydospores, sporangia, and zygospores. Sporangia globose to elongate, containing one to three sporangiospores. Zygospores formed from conjugation of two adjacent hyphal cells; thickwalled, 30-50 n in diameter. 3. A bsidia van Tieghem. Plate 45.

t s

- v\

Mycelium formed as in the genus Rhizopus by frequently branched stolons, more or less incurved into arches and producing at point of contact with substratum more or less richly branched rhizoids. Sporangiophores straight, rarely single, more often in groups of two to five, occurring on the arc of the stolon (internodal) and not at the point of origin of the rhizoid (nodes). At times there occur erect stolons or branches bearing lateral sporangiferous branches which may be confused with primary sporangiophores. Sporangia apparently equal, pyriform, erect, fur-

324

Medical mycology

nished with an infundibuliform apophysis. Membrane of sporangium not cuticularized or encrusted; diffluent, leaving a short basal collarette. Columellae hemispherical, conic, or mammiform, more rarely spinescent or terminated by a single prolongation. A cross wall is placed at a definite distance below sporangium. Spores small, 5-6 ¡x, round or oval (not angular) with smooth wall, rarely echinulate, colorless or bluish-black. Apparently closely related to genus Rhizopus, but differing from it by the fact that the sporangiophores occur on the internodes, by the pyriform sporangia, by the continuance of the columellae into the apophyses. 4. Rhizopus Ehrenberg. Plate 45. Mycelium of two kinds, one submerged in substratum and the other aerial, constituting the arching filaments or stolons. These stolons present from place to place the nodes on which occur the rhizoids, which are implanted in substratum. At these points sporangiophores arise. They may be single but usually occur in groups of two, three, or more. T h e summit of the sporangiophore is enlarged into an apophysis, of the kind that has the columella inserted above the point where the spherical bend attaches into the filament. T h e sporangia, white at first, become bluish-black at maturity. They are all the same shape, spherical or almost spherical, flattened at the base. Wall not cuticularized, uniformly encrusted and entirely diffluent, leaving a basal collarette. Columellae broadly hemispherical, forming after dehiscence, by collapse, an organ of the shape of the pileus of a mushroom. Spores round or oval, angular, colorless or colored bluish or brown, with a cuticularized wall, smooth or striate, rarely spinulose. Zygospores naked, formed in substratum and on stolons. Suspensors straight, very large and swollen, without appendages. Rhizopus nigricans Ehrenberg.

Stolons creeping, recurving to substratum in form of arachnoid hyphae, which are strongly raised and distant from the substrate and implanted at each node by means of rhizoids. Internodes often attain length of 1-3 cm, and hyphae are more or less branched. Sporangiophores rarely single, united in groups of three to five or more, 0.5-4.0 mm in height by 24-42

Fungi of importance in medical mycology

325

mm in diameter. Apophyses broad, cuneiform. Sporangia hemispherical, 100-350 /x. Columellae broad, hemispheric, depressed, 70 ¡x in diameter by 90 /j. in height. Spores unequal, irregular, round, oval, or angular, striate, 9-12 fi long by 7.5-8.0 fi in diameter, of a gray-blue color. Zygospores are round or oval, 160-220 ¡x in diameter. Exospore brown-black, verrucose. Suspensors swollen, usually unequal. Azygospores present. No chlamydospores. Rhizopus arrhizus Fischer.

Differs from R. nigricans by being less exuberant. T h e felt is clearer and it does not extend so far into substratum. Stolons are little developed and do not form nodes regularly. Rhizoids pale, develop at nodes and carry sporangia, or are sometimes formed indeterminately. Sporangiophores often prostrate, rarely single, forming umbels or corymbs on their stolons. They measure 0.5-2.0 mm in length. All branches end in sporangia, of greater or less size. Sporangia spherical, 120-250 ¡x in diameter. Columellae spherical, flattened on apophyses, 40-75 ¡x high by 60-100 p in width, membrane brown, smooth. Spores round or oval, or presenting obtuse angles, grayish-brown; walls striated longitudinally, 4.8-7.0 ¡x by 4.8-5.6 fX. Rhizopus oryzeae Went and Geerlings. Colonies rapidly growing, completely filling culture dish with loose grayish-white mycelium which darkens with age and assumes yellowishbrown color. Mycelium broad, 15-20 ¡x in diameter, with numerous stolons bearing clusters of relatively short yellowish-brown sporangiophores subtended by well-developed yellow-brown rhizoids. Sporangia dark brown, spherical (100-160 ¡x in diameter); sporangial wall thin and easily ruptured, releasing their spores and revealing flat-domed hyaline columella (45-120 ¡x in diameter). Sporangiospores light brown, striated, broadly ovate to subglobose or slightly irregular in shape, 6.0-8.5 V- by 5-6 ¡xCultures grow equally well at room temperature and at 37 °C. This species is differentiated from R. nigricans and R. arrhizus by color of turf, flatdomed columella, and numerous rhizoids and indefinite stolons.

Medical mycology

5. Mucor Micheli. Plate 45.

Mycelium widespread in and on substratum, but without rhizoids or especial membered stolons; richly branched, with branches always thinner until at last hair-fine; straight or knotted at first, 1-celled; in age with irregular cross walls, with colorless, infrequently orange-red content; smooth, colorless membrane. Sporangiophores springing singly from mycelium but usually forming thick turf, erect, either unbranched with terminal sporangia or branched with like sporangia on all the branch ends; branching in part monopodial, clustered, or irregularly panicled or umbelliferous; in part cymose and more or less sympodial, curved, with sporangia also at tip of sympodium, never forked. Sporangia erect at all times on sympodial sporangiophores, a few weakly bent, usually all alike, only of different size; many-spored, spherical, opening on sporangiophore, only a few in sympodial forms abscissing while still closed; of various colors. Sporangial wall not cuticularized, encrusted more or less strongly with needles of calcium oxalate, dissolving quickly in water, leaving a collarette, or breaking and then at times persistent. Columellae always present, of various shapes, colorless or colored. Spores spherical or el-

Fungi of importance in medical mycology

327

lipsoid with thin, smooth membrane, colorless or colored. Chlamydospores terminal and intercalary, variously formed, colorless, smooth; not in all species. 6. Circinella van Tieghem and Le Monnier. Plate 45.

Mycelium strongly branched, at first nonseptate, becoming divided. Lateral branches become more and more delicate. Sporangiophores erect on mycelium, branching in sympodia; tip grows indefinitely, and never terminates in a sporangium. Lateral branches, united into whorls or single, are curved and carry at their tips sporangia of like dimensions. Sporangia many-spored, spherical, with the wall encrusted with calcium oxalate crystals, nondiffluent, but breaking into pieces, leaving an irregular collarette at base. Columellae large, slightly concrescent at base, cylindroconic, sometimes panduriform. Spores spherical or oval, smooth, more or less slate blue. Zygospores borne on erect hyphae distinct from sporangiophores. Suspensors without appendages. 7. Syncephalastrum racemosum Cohn ex Schroeter.

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Medical mycology

Colonies on YpSs or PDA remaining nearly white or becoming "drab" to "deep neutral gray," 0.5-1.5 cm high; vegetative hyphae growing rapidly at 2i°C, colorless, becoming highly branched, 4-8 ¡x in diameter, nonseptate at first, irregularly septate in age; septa simple, without median perforations; sporangiophores arising directly from vegetative hyphae, at first simple, nonseptate, erect, ascending, or recumbent, often stolonlike and producing adventitious rhizoids, becoming irregularly racemosely or cymosely branched and forming a densely intertwined aerial mycelium; primary axes of sporophores 10-25 ^ in diameter, producing terminal globose or ovoid enlargements, 30-80 ¡j,; lateral branches straight or sharply recurved, highly variable, 20-300 ¡i or more in length, 5-15 ¡x in diameter, producing terminal vesicles about 10-40 ¡x in diameter; vesicles, at maturity, usually subtended by simple septa; numerous septa also formed at irregular intervals in sporophores; terminal enlargements of sporophores fertile, giving rise, by budding, usually over entire surface, to rodlike merosporangia and forming pale to dark-gray or brownish spore-heads about 40-150 f>, in diameter; vesicles becoming pale gray or brownish in color and contrasting sharply with hyaline or only slightly pigmented sporophores; merosporangia slender, normally containing single row of 3-5 to 10-18 smooth sporangiospores; a second usually incomplete file of spores not uncommon; sporangiospores globose or ovoid, about 3-5 fx in diameter; more rarely oblong or cylindrical; merosporangial wall evanescent; heads not forming spore-drops at maturity; heterothallic. 8. Cunninghamella

Matruchot. Plate 45.

Mycelium white, floccose, slightly thickened, 3-6 ¡x, continuous when young, later becoming septate, septa disposed here and there without order. Rhizoids very tenuous. Conidiophores straight, branched. Main axis, as well as side branches, little or not septate, terminating in spherical heads, furnished with small swellings which are points of insertion for conidia. Conidia spherical or oval, often with irregular outline, external membrane smooth or spiny with needle-like crystals. Chlamydospores globose, intercalary in mycelium.

Fungi of importance in medical mycology

329

9. Saccharomyces (Meyer) Rees. Plate 45. (Ji '

A

i

©fei

J Colonies moist, pasty white or cream-colored. Cells of various shape, round, oval, elongate, or threadlike. Vegetative reproduction by multilateral budding. Pseudomycelium may be formed. Isogamous or heterogamous conjugation may or may not precede ascus formation. Protuberances resembling conjugation tubes may be formed. Ascospores are usually spherical or oval, seldom hat-shaped, angular, or reniform. Commonly one to four spores per ascus; spore conjugation within ascus may occur. Vigorous fermentation of glucose and most other sugars. 10. Gymnoascus Baranetzky. Plate 45.

Cleistothecia more or less globose, usually white or in light or bright colors, rarely darker. Peridial hyphae loosely reticulate, anastomosed, thick-walled, septate, smooth or asperulate, with many free apices, either spinelike or elongate septate branches which terminate in short, pointed or obtuse, straight or slightly curved branchlets. Asci globose, subglobose,

330

Medical mycology

or obovate, usually 8-spored, wall evanescent. Ascospores hyaline or brightly colored or tinged brown, globose, oblate, elliptical or lenticular, smooth or sculptured. Asexual phase absent. 11. Arthroderma Berkeley. Plate 45.

Cleistothecia white to pale yellow, globose. Peridial hyphae hyaline, branched and anastomosed, thick-walled, densely asperulate, with constricted, symmetrical or asymmetrical, dumbbell-shaped cells; thin-walled, septate, elongate, spiral appendages occurring terminally or laterally, with numerous free ends. Asci globose, 8-spored, wall evanescent. Ascospores yellow in mass, ovoid, or lenticular, smooth. Chlamydospores (aleuriospores) abundant, clavate. Arthroderma uncinatum'Dawson and Gentles 1961.

Heterothallic. Cleistothecia globose, pale buff, 300-900 ¡i av. 500 /x, in diameter, excluding appendages. Peridium 90-150 ¡i, av. 125 ¡x thick. Peridial hyphae pale yellow, hyaline, septate, uncinately branched usually to one side, the outside, of main hypha. Cells thick-walled, strongly echinu-

Fungi of importance in medical mycology

331

late, symmetrically dumbbell-shaped, 7-11 ¡l by 4-7 fx. Appendages: (1) septate spirals, varying considerably in length and number of turns, lateral or terminal; (2) smooth-walled, multiseptate, fusiform macroconidia, lateral or terminal. Asci subglobose, thin-walled, evanescent, 5.4-7.2 (i by 4.9-6.3 fi, 8-spored. Ascospores hyaline, smooth or finely roughened, lenticular, 2.3-2.7 /x by 1.4-1.8 ¡x, yellow in mass. Conidial state: Keratinomyces ajelloi Vanbreuseghem 1952. Habitat: Soil. Arthroderma quad.rifi.duin Dawson and Gentles 1961. Heterothallic. Cleistothecia globose, pale buff, 400-700 p, av. 580 ¡x, in diameter excluding appendages. Peridium 80-135 ¡x, av. 103 ¡x, thick. Peridial hyphae pale yellow, hyaline, septate, uncinately branched usually to one side, the outside, of main hypha. Cells thick-walled, strongly echinulate, dumbbell-shaped when young, when mature resembling short humerus bone with condyles much accentuated and formed on one face only, 8-13 ¡x by 5-9 /X. Appendages: septate spirals which vary considerably in length and number of turns, lateral or terminal. Asci subglobose, thinwalled, evanescent, 3-6 ¡x by 3.5-5 //,, 8-spored. Ascospores hyaline, smooth or finely roughened, lenticular, 1.8-2.7 M by 0.9-1.8 ¡x, yellow in mass. Conidial state: Trichophyton terrestre Durie and Frey (1957). Habitat: Soil, hair of wild rat, horse. 12. Nannizzia Stockdale.

Cleistothecia globose. Peridium consisting of network of hyaline, septate, verticillately branched hyphae. Cells moderately thick-walled, densely asperulate, more or less symmetrically constricted. Hyphae with numerous free ends, and with appendages of three kinds: (1) elongate, slender, smooth-walled, septate, occasionally branching, straight or loosely coiled hyphae; (2) elongate, slender, smooth-walled, septate, occasionally branching, tightly coiled hyphae; (3) macroconidia. Asci globose to ovate, hyaline, 8-spored. Ascospores yellow, lenticular. Named after Dr. Arturo Nannizzi.

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Medical mycology

Nannizzia incurvata Stockdale 1961. Heterothallic. Cleistothecia formed abundantly on autoclaved soil or natural, untreated soil mixed with child's hair, horsehair, or chicken feathers. Cleistothecial initials composed of clavate antheridium surrounded by coiled ascogonium. Cleistothecia globose, pale buff, 350-650 p, rarely up to 900 ¡x in diameter excluding appendages. Peridium composed of network of pale-buff, hyaline, septate, branched hypae with thin, densely verruculose walls. Up to five branches arising in succession at apex of same cell and curving in toward their main axis, away from cleistothecium. Inner cells of peridial hyphae not constricted, often swollen toward apex, 24-40 ¡j, by 5-8 ¡x, sometimes up to ii/x wide at apex. Outer cells usually more or less symmetrically constricted with 1 - 3 constrictions, 10-25 P- by 4.5-8.0 ¡j.. Appendages: (1) straight, slender, smoothwalled, septate, rarely branched hyphae, up to 300 ¡x long, 3.0-4.5 ¡x in diameter at base tapering to 1.5-2.0 ¡x in diameter; (2) slender, smoothwalled, septate, rarely branched spiral hyphae, 2.5-3.5 M i n diameter at base tapering to 1.5-2.0 p. in diameter coiled with up to 30 turns; (3) ellipsoid or fusiform macroconidia, 40-57 ¡i by 9.5-12.5 ¡x, 1 - 5 septate, with moderately thickened, verrucose walls. Branches and appendages almost always borne at apices, rarely on sides, of cells of peridial hyphae. Asci subglobose, thin-walled, evanescent, 5-7 ¡x in diameter, 8-spored. Ascospores smooth-walled, lenticular, yellow in mass, 1.5-2.0 ¡x by 2.5-3.0 ¡x (usually not more than 3.2 ¡x). Conidial state: Microsporutn gypseum (Bodin) Guiart and Grigorakis sensu lato. Nannizzia obtusa Dawson and Gentles 1961. Heterothallic. Cleistothecia globose, pale buff, 250-450 ¡x in diameter, excluding appendages. Peridium approx. 50 ¡1 thick. Peridial hyphae pale yellow, hyaline, septate, branching mostly dichotomous, occasionally verticillate, angle between branch and main hypha usually obtuse. Cells thick-walled, echinulate, cylindrical, 8-20 ¡x, av. 13^, by 4-7 ¡x, may have one or two slight constrictions. Appendages: (1) septate, smooth-walled, tightly coiled spirals, lateral or terminal; (2) elongated, slender, septate hyphae up to 450 ¡x in length, terminal. Asci subglobose, thin-walled, evanescent, 5.5-6.5 ¡x by 5-6 ¡x, 8-spored. Ascospores hyaline, smooth or finely roughened, lenticular, 2.7-3.2 ¡x by 1.2-2.0 ¡x, yellow in mass. Conidial state: Microsporutn nanum Fuentes (1956). Habitat: Isolates, from ringworm lesions in humans and in pigs, cultivated in soil. Nannizzia cajetana Ajello 1961. Heterothallic. Cleistothecia globose, pale yellow, 368-686 ¡x in diameter. Peridial hyphae hyaline, septate, verticillately branched. Mycelial cells echinulate, thin-walled, and slightly constricted at side of septations. Free ends of peridial hyphae numerous with two kinds of appendages: (1) elongated, slender, tapered, smooth hyphae up to 480 ¡x in length, 3.6 ¡x

Fungi of importance in medical mycology

333

in diameter at base, 2.4 p. at mid-length, 1.2 ¡x at tip; (2) elongate, smoothwalled, slender hyphae coiled into spirals. Asci globose or ovate, 6-9 ¡x in diameter, 8-spored. Ascospores ovate, smooth-walled, and golden, 3.03.6 by 1.8 fi. Conidial state: Microsporum cookei Ajello 1959. Habitat: Soil, keratinophilic. Nannizzia grubyia Georg. Heterothallic. Cleistothecia globose, white to pale buff, 150-600 ¡x in diameter exclusive of appendages. Peridial hyphae hyaline, septate, branching dichotomously and uncinately, mostly curved to one side, the outside, of main hypha. Cells moderately thick-walled, densely echinulate, moderately constricted at central part (similar to phalanges of hand) generally 4-5 ju in diameter, occasionally 7.5-10.0 ¡x- Free ends of peridial hyphae terminate bluntly or as rounded points, or taper into smoothwalled, loosely coiled hyphae of 2-3 turns, or into elongate (up to 300 ¡x long), thin, smooth-walled, septate hyphae tapering from 3.0-1.5 ¡x in diameter with up to 30-50 tight coils. Macroconidia thick-walled, cylindrofusiform, multiseptate, and densely echinulate, borne laterally and terminally on peridial hyphae. Asci globose, thin-walled, evanescent, 4.8-6.0 fi in diameter, 8-spored. Ascospores hyaline, pale yellow, smooth-walled, ovate, 2.4 ¡J. by 3.0 ¡x. Conidial state: Microsporum vanbreuseghemii. Habitat: Skin and hair of animals and man. Nannizzia gypsea (Nannizzi) Stockdale 1963. Basonym: Gymnoascus gypseus Nannizzi 1927. Heterothallic. Cleistothecia formed abundantly on autoclaved soil or natural, untreated soil mixed with child's hair, horsehair, or chicken feathers. Cleistothecial initials composed of central clavate antheridium surrounded by coiled ascogonium. Cleistothecia globose, pale buff, 300750 ¡1, occasionally up to 900 ¡x, in diameter excluding appendages. Peridium composed of network of pale-buff, hyaline, septate, branched hyphae with thin, densely verruculose walls. Up to four branches arising in succession at apex of same cell and curving over cleistothecium. Inner cells of peridial hyphae not constricted, often swollen toward apex, 20-35 ¡x by 4.5-8.0 /X, sometimes up to 10 /x wide at apex. Outer cells usually more or less symmetrically constricted with 1-3 constrictions, 8-20 fx by 4-7 ¡x. Appendages: (1) straight, slender, smooth-walled, septate hyphae, up to 250 ¡x long, 2.5-4.0 /x at base tapering to 1.5-2.0 ¡x; (2) slender, smooth-walled, septate, spiral hyphae, rarely branched, 2.5-3.5 /•

I

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In dandruff scales organism appears as small blue staining bodies, some dense, some vacuolated, of characteristic round or elongated bottle shape, average size being 0.9-2.0 ft. In original cultures on wort agar growth is first noted about dandruff scales, cream to tan or orange and dry in appearance. If suspension of this growth is pipetted over surface of wort

Fungi of importance in medical mycology

341

agar to which oleic acid has been added, growth appears in four or five days. It appears first as tiny cream-colored colonies which later fuse, becoming dry and wrinkled with color varying from cream to tan or orange. Microscopically, several forms are seen in culture though usually cells appear as elongate structures 2-3 ¡x by 4-5 ¡x. Many elongate budding cells are seen. In some instances the bud has elongated, forming necklike projection, the so-called bottle form. Often cells appear to be joined by a septum, indicating that reproduction is intermediary between budding and septation. No pseudomycelium or mycelium is formed, nor is multiple budding observed. Pityrosporum orbiculare Gordon.

Cells spherical, usually in clusters on artificial media, double-contoured, 2.1-4.8 ft. in diameter, mostly 2.8-3.8 ¡x, producing single (rarely 2 or 3) spherical to oval buds on narrow base. On Sabouraud's agar or wort agar very little growth unless olive oil or other fatty substance is layered on surface; on Sabouraud's agar and other media, with olive oil or stearic acid, excellent growth at 37°C after one week, no growth at 25°C after two weeks; no growth with oleic acid or mineral oil and, in most strains, none with glycerin. On glucose-peptone broth overlaid with olive oil growth occurs only at interface. 23. Malassezia furfur (Robin) Baillon. Plate 46. On Sabouraud's agar, overlaid with olive oil or other fatty substance and inoculated with scales from skin lesions, small moist colonies slowly develop. Transfers from these colonies when streaked on new media develop more rapidly and form yellowish-brown colonies. Growth is composed of ovate or spherical cells and short septate filaments. In some instances "spores" appear to emerge from phialide-like filaments. Cells and filaments appear similar to those seen in some cultures of Pityrosporum orbiculare. Quite probably there is only one species (Keddie and Shadomy, 1963)-

It

br>v ¿J mm

Colony yeastlike or bacteria-like, pasty to mucoid, yellow, orange, pink, or red owing to presence of carotenoid pigments. Growth consisting of oval, budding, yeast cells, small, usually budding singly; occasionally cells are elongated into more or less primitive pseudomycelium. No fermentation, no urease. 25. Candida Berkhout. Cells of varying shape. Reproduction by multilateral budding. Chlamydospores may be present. Pseudomycelium more or less abundantly developed; besides, true mycelium may occur. Blastospores may be attached to mycelium or pseudomycelium in a way typical of species. In liquid media bottom growth, often ring formation and often a pellicle. Besides an oxidative dissimilation in many species, there is a more or less strong fermentative dissimilation. Candida albicans (Robin) Berkhout. Growth on solid media rapid at room temperature or at 37 °C. Giant

colonies soft, glistening, rather flat or sometimes dull, raised and tough; color cream to yellowish-cream. Surface smooth, or may show pimples or craters in older colonies due to escaping gas. In most strains margin is smooth with halo of hyphal strands growing in agar; hyphae rarely develop at surface surrounding margin. Microscopically, soft surface growth is composed of nearly spherical blastospores. Mycelium and pseudomycelium are abundant in subsurface growth. Development of ball-like clusters (verticils) of blastospores along mycelial filaments is characteristic of this species. Very characteristic, too, although not always present on Sabouraud's medium, are large round chlamydospores which are usually formed terminally, but also intercalary, pleurally, or in clusters. The thin-walled protochlamydospores on which lateral chlamydospores may arise are round, elongate, or somewhat bottleshaped to pear-shaped. Chlamydospores are abundant in cornmeal agar cultures. Glucose, maltose, and galactose (often weak) fermentation. Candida tropicalis

Berkhout.

»

Growth on Sabouraud's agar is abundant, mainly consisting of globular or slightly ovoid cells 2.5-7.0 ¡L in diameter. Colonies cream to yellowish, dull and tough, the entire surface folded, often hirsute, with smooth margin, surrounded by mycelium. On slide culture the pseudomycelium

344

Medical mycology

develops abundantly; true mycelium is also found. T h e verticils are well developed, single or branched. Chains of blastospores are often formed and single blastospores may also be seen attached to sides of hyphae. Fermentation of glucose, galactose, sucrose, maltose. Candida krusei (Castellani) Berkhout. » %

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t l i f i 2 73- 3 8 5 Blastomyces dermatitidis, 8-10, 84-87, 90, 92-95, 104-105, 286, 320, 357-358; use of amphotericin B, 22; eye infection, 273; dimorphism, 302-303; cultural isolation, 396, 401 f. Blastomycin, 86, 95, 97 Blastomycosis. See North American blastomycosis; South American blastomycosis Blastospores, 284 Bone: effect of coccidioidomycosis, 32. f.; sporotrichosis, 54; histoplasmosis, 71; N. American blastomycosis, 88; S. American blastomycosis, 105; cryptococcosis, 1 1 1 , 116, 118, 120; actinomycosis, 133, 135 f.; mycetoma, 152, 154, 158; aspergillosis, 200 f.

Index Bone marrow: histoplasmosis affects, 71; cryptococcosis, 118 Botrytis, 320, 356 Brain-heart infusion cycloheximide chloramphenicol agar, 405 Cadophora americana, 181 Candida, 22, 172 f., 198, 316, 342, 394 Candida albicans, 165-175 passim, 215, 2 95- 342-343; and amphotericin B, 22; and dermatophytosis, 224f„ 229, 242; and otomycosis, 269; in nail disease, 270; industrial disease, 276; culturing, 397,405 Candida brumptii, 344 Candida krusei, 344 Candida tropicalis, 343-344 Candidiasis (Moniliasis), 165-177, 233 Carpenteles, 316 Cavitation: in coccidioidomycosis, 28 f., 31, 41 f.; pulmonary histoplasmosis, 69, 71, 78; N. American blastomycosis, 91, 99; S. American blastomycosis, 104; pulmonary nocardiosis, 146 Central nervous system: C. neoformans attacks, 8, 1 1 1 , 1 1 4 - 1 1 8 , 1 2 4 ! ; in coccidioidomycosis, 34, 42; other systemic mycoses, 71, 88, 104, 133; nocardiosis, 144, 146-147; intermediate mycoses, 171, 182, 190, 192; and eye involvement, 273 Cephalosporium, 156, 319, 348 Cervicofacial actinomycosis, 133, 137, 140 Chaetomium, 317, 336 Chancriform syndrome, 8 - 1 1 , 13, 19; in coccidioidomycosis, 35; sporotrichosis, 49, 53» 59 f.; N. American blastomycosis, 85, 90; nocardiosis, 145; chromoblastomycosis, 185 Chicago disease. See N o r t h American blastomycosis Chlamydospores, 284 Christensen's urea agar, 404, 406 Chromoblastomycosis, 179-186 Chromophytosis. See T i n e a versicolor Chrysosporium, 357 Chrysosporium (Blastomyces) dermatitidis, 302-303, 320, 357-358 Chrysosporium parvum, 320, 358 Circinella, 315, 327 Cladosporium (Hormodendrum), 181, 184, 321. 3757378 Cladosporium bantianum, 379 Cladosporium carrionii, 184, 378 Cladosporium mansoni, 260 Cladosporium trichoides, 379 Cladosporium wernickii, 259-262, 378 Cleistothecium, 290 Coccidioides immitis, 10, 26®., 34-36, 319, 346-347; and chancriform syndrome, 8 -

Index 9; immunology, 15, 36-38, 40; drug therapy, 22, 43 f.; eye involvement, 273; as compensable disease, 277; dimorphism, 300 f.; isolating from sputum, 401; isolating from soil, 403 Coccidioidids, 29 Coccidioidin, 15 f., 28 ff., 36, 38-43, 58 f., 65 Coccidioidomas, 29 Coccidioidomycosis, 25-44, 53-54; and chancriform syndrome, 9, 11; immunologic aspects, 14 ff., 23, 37-42; drugs, 22, 42-44; pulmonary, 28-29; cutaneous, 2932; disseminated, 32-34 Columella, 285 Complement-fixation reaction, 15, 17-18; coccidioidomycosis, 36, 39-44; sporotrichosis, 59, 61; histoplasmosis, 74, 76-77, 78; B. dermatitidis, 95, 97-98; S. American blastomycosis, 106-107; actinomycosis, 139; mycetoma, 158 Conidia, 285-286 Conidiophores, 285 f. Coremium, 286 f. Corneal ulcers, 155, 272-273 Cornebacterium tenuis, 269 Corticosteroids, 20, 41, 77, 108, 125; favor cryptococcosis, 113; favor candidiasis, 166 f., 170, 174; factor in phycomycosis, 190, 192, 194; in aspergillosis, 198 f., 203; eye mycoses, 272 f. Cryptococcoma, 115, 118 Cryptococcosis, 41, 111-125; immunology, 13 f., 17, 121-124; pulmonary, 114-116; disseminated, 116-118 Cryptococcus, 317, 339; isolation from soil, 403-404 Cryptococcus genitalis, 118 Cryptococcus neoformans, 8, 10, 22, 37, 111-121 passim, 339, 405; immunology, 14, 121-124; eye infection, 273; isolation from sputum, 401 f.; isolation from soil. 404 Culture: methods, 394-395; media, 395396, 404-406; inoculation and isolation, 396-399; examination and interpretation, 399-400; slides, 400-401; isolation from soil, 402-404; preserving, 406-407 Cunninghamella, 190, 316, 328 Cushing's syndrome, 232 Dematium, 321, 373 Dendrostilbella, 322, 336, 383 Dermatomycosis furfuracea. See Tinea versicolor Dermatophytes, 213-217, 295; and aspergillosis, 198; and tinea cruris, 224, 229; causing tinea pedum and manuum, 225;

423 immunity, 230 f. See also Dermatophytosis Dermatophytid reactions, 236-238 Dermatophytosis, 213-246; characteristics, 216-228; immunology, 230-238; therapy, 238-246; compensable cases of, 276 Deuteromycetes, 286, 309 ff., 317 Diabetes: and resistance to mycoses, 20, 113, 157, 200, 232; and candidiasis, 167 f., 170, 172, 174-175; in phycomycosis, 190»94. 273 Diagnosis: laboratory methods of, 392-407 Dimorphism, 300-305 Discomycetes, 290 Dissemination, 11, 19; of coccidioidomycosis, 30 f., 32-34, 42-43; sporotrichosis, 53 f., 60 f.; histoplasmosis, 67 f., 72, 7475, 76®.; N. American blastomycosis, 84-99 passim; S. American blastomycosis, 103, 105; cryptococcosis, 113 ff., 116-118; actinomycosis, 135 f.; nocardiosis, 144 ff.; candidiasis, 171; chromoblastomycosis, 182; aspergillosis, 200 Elephantiasis: in chromoblastomycosis, 181, 186 Emericella, 316 Emmonsia crescens, 358 Emmonsia parva, 320, 358 Emmonsia (Chrysosporium) (Haplosporangium) parva, 305 Emmonsia (Chrysosporium) parva and variety crescens, 304 Endogenous spores, 283 ff. Endophthalmitis, 273 Entomophthora coronata, 315 Eosinophilia: in coccidioidomycosis, 29, 34 Epicoccum, 322, 384 Epidermal effluvial current, 233-235, 242, 244, 246 Epidermophyton, 320 Epidermophyton floccosum, 224 f., 363 Eremascus fertilis, 289 Erosio interdigitalis blastomycetica, 168 Erythema multiforme: in coccidioidomycosis, 29, 34 Erythema nodosum: in coccidioidomycosis, 29; in N. American blastomycosis, 88, 97 Erythrasma, 269-270 Eumycophyta, 309, 314 Eurotiales, 310 Eurotium, 316 Exogenous spores, 283-284 Extracellular starch production, 406 Eye: disorders of, in cryptococcosis, 117; involvement in rhinosporidiosis, 207; mycoses of, 272-274

424 Favus, 214, 22g, 233 Fertilization tubes, 288 Filaments, 281 Flare reaction: to coccidioidin test, 40; in sporotrichosis, 58; to histoplasmin, 76 Fluorescent-antibody technique, 16, 77 Folliculitis, fungal, 226 Fonsecaea, 183 Foot: in actinomycosis, 136; mycetoma, 150, 152; T. rubrum affects, 232. See also Tinea pedum Formalin: for piedra, 267 Freezing: to preserve cultures, 407 Freezing agar (modified PDA), 405 Froin's syndrome, 43 Fruiting bodies, 286 f., 290 Fungi Imperfecti, 298, 309 t., 312 Fusarium, 286, 322, 384 Gametangium, 287 ff. Gastroenteritis: factor in phycomycosis, 190 Gel-diffusion techniques, 16, 40, 77 Gentian violet, 175-176 Geotrichum, 37, 270, 319 Geotrichum candidum, 177, 346 Gilchrist's disease. See North American blastomycosis Glenospora, 156 Glenospora loboi, 106 Gliocladium, 319, 352 Granuloma: coccidioidal, 32-34, 42; in histoplasmosis, 71 f., 75, 78; S. American blastomycosis, 104 f.; monilial, 170 f.; perifollicular, 227 f. Gray-patch ringworm, 217 Griseofulvin, 11, 23; for sporotrichosis, 61; for mycetoma, 159; for phycomycosis, 194; for dermatophytosis, 229, 238-246 Gymnoascaceae Imperfecti, 319, 347-348 Gymnoascus, 316, 329-330 Gymnoascus gypseus, 333 Hair: sporotrichosis penetration into, 52; and dermatophytes, 213, 215, 230; effect of tinea capitis on, 217 f., 220 f.; invaded by tinea pedum, 226; and epidermal effluvial current, 234; and griseofulvin therapy, 242; study of, 393-394. See also Piedra Hand: mycetoma, 150; ringworm of, 225227; onychomycosis and disease of, 228; T. rubrum infection, 232; tinea nigra, 259-263 Haplosporangium parvum, 320, 358 Haustoria, 283, 294 Heart: monilial endocarditis, 171; congenital disease of, and phycomycosis, 190 Helminthosporium, 321, 37g

Index Hemopoietic system: and disseminated histoplasmosis, 75 Hepatic disease: as factor in phycomycosis, 190 Hepatitis, infective: with cryptococcosis, 113 Hereditary factor: in favus, 233; in tinea versicolor, 257 Heterosportum, 321, 379-380 Histopathologic study, methods of, 392394 Histoplasma, 10, 286, 320 Histoplasma capsulatum, 65, 70-71, 73, 286, 359-360; immunology, 14, 74; amphotericin B, 22; sources, 66 f., 69; dimorphism, 300-302; cultural isolation, 401 Histoplasma duboisii, 66, 71 ff. Histoplasmin, 66, 74 ff. Histoplasmoma, 72 Histoplasmosis, 9, 13, 38, 41, 64-78; immunology, 14, 74-77; characteristics of, 67-71; mycology of, 73-74; therapy in, 77-78; and pulmonary aspergilloma, 199 Hodgkin's disease: and deep mycoses, 20, 7i. 75- " 3 Hormodendrum. See Cladosporium Hymenium, 290 f. Hyphae, 281-283; fusion of, 299 Hypocreaceae, 359 Hypoparathyroidism: favors candidiasis, >74 Immune adherence phenomenon, 16 Immunological resistance, 13-20; and chancriform syndrome, 10 f.; and drugs, 22 f., 244; to coccidioidomycosis, 25, 30 ff., 38-41, 44; to sporotrichosis, 50, 53, 5761; to histoplasmosis, 74-77; to N. American blastomycosis, 90 f., 94-98; to S. American blastomycosis, 106 ff.; to cryptococcosis, 113, 122; to actinomycosis, 139; to nocardiosis, 148; to mycetoma, 157-158; to dermatophytes, 230-238 Indiella, 156 Inoculation technique, 396-397 Intertrigo, 167-168, 173 ff. Intracutaneous tests. See Skin tests Iodide therapy: for sporotrichosis, 20, 6061 Isaria, 321, 382 Isolation (cultures): from sputum, 396-398; from soil, 402-404 Jorge Lobo's disease, 105 f., 295 Keratin, 8, 213, 230; and epidermal effluvial current, 234, 236; and tinea versicolor, 254, 258 Keratinomyces, 321

Index Keratinomyces ajelloi, 300, 331, 372 Keratolytics, 239, 244, 263 Kerion Celsi, 218, 220, 222, 235 Kleinflechte. See Tinea versicolor Lactophenol, 400 f. Lactophenol cotton blue, 400 Leukemia: and deep mycoses, 20, 71, 75, 113; as factor in phycomycosis, igo Loboa loboi, 106 Lumpy jaw, 131 Lungs, g; in coccidioidomycosis, 31 if., 42; other deep mycoses, 54, 103-104, 144 f.; histoplasmosis, 66, 68, 70, 72, 78; blastomycosis, 84 f., 88 f., 91, g6; cryptococcosis, 114-116, 118, 125 Lutziomyces histo-sporo-cellularis, 105 Lutziomycin, 106 Lycoperdales, 310 Lymphadenopathy: in sporotrichosis, 8; coccidioidomycosis, 30 f.; histoplasmosis, 6g, 71 £.; blastomycosis, 87, gi; S. American blastomycosis, 103 Lymphangitis: in sporotrichosis, 8, 52; coccidioidomycosis, 30; histoplasmosis, 6g; blastomycosis, 87, 91 Lymph nodes, 8; coccidioidomycosis, 30, 35; involvement in sporotrichosis, 52-53; histoplasmosis, 68 f., 71 f., 77; blastomycosis, 87, 91; S. American blastomycosis, 101, 103, 105; cryptococcosis, 117 Lymphoblastoma: associated with mycoses, 20, 75, 113, 157, 174, 190, ig4, 198, 232 Lymphosarcoma: with histoplasmosis, 71, 75 Macroaleuriospores: H. capsulatum, 73 Macrosporium, 321, 337, 381 Madura foot, 136, 150 Madurella grisea, 155 f., 159 Madurella mycetomi, 153, 155, 159 Maduromycosis, 17, 136, 150, 159 Malassezia, 317, 394 Malassezia furfur, 8, 172, 233, 252-253, 255257. 296. 341 Meningitis: coccidioidal, 33 f., 42 f.; blastomycosis, 88; cryptococcic, 113 f., 116, 118, 120, 125 Methylrosaniline chloride (gentian violet), 175-176 Microaleuriospores: H. capsulatum, 73 Microscopic examination, 400 Microsporum, 214, 222, 241, 286, 321, 369, 371 Microsporum audouinii, 217, 219, 2g5, 369370, 371; culture methods, 394, 397 Microsporum canis (lanosum, felinum), 217-218, 219, 370; culturing, 397

425 Microsporum cookei, 333, 371-372 Microsporum fulvum, 334 Microsporum gypseum, 218 f., 300, 332, 334, 370 f. Microsporum nanum, 332, 370 f. Microsporum vanbreuseghemii, 333, 370 f. Mildews, 294 Monilia, 319, 345-346 Monilial endocarditis, 171 Moniliales, 311 Monilial granuloma, 170 f., 176 Moniliasis. See Candidiasis Monosporium, 320, 336 Monosporium apiospermum, 153, 155, i5g, 335- 355~356 Mortierella, igo, 193 Mucor, 190, ig3, 315, 326-327 Mucorales, 288 Mucormycosis. See Phycomycosis Mucous membranes: lesions of, in mycoscs, 53, 117, 207; histoplasmosis, 69 ff.; S. American blastomycosis, 101, 103, 105 Mushrooms, 291 Mutation, 298-299 Mycelium, 282—283, 399 Mycetoma, 130, 136, 143, 150-159 Mycobacterium tuberculosis, 158, 238 Myocarditis, 146, 159, 200 Myriangiales, 310 Myxomycophyta, 309 Myxotrichum, 316, 334-335 Nails, 215, 235, 244; tinea of, 227-22g; treating tinea, 240, 245-246; evulsion, 239, 246; studying, 393. See also Onycholysis; Onychomycosis; Paronychia Nannizzia, 316, 331 Nannizzia cajetana, 332-333, 372 Nannizzia fulva, 334 Nannizzia grubyia, 333, 370 Nannizzia gypsea, 333-334 Nannizzia incurvata, 332, 370 Nannizzia obtusa, 332, 370 Neoplasm: factor in phycomycosis, 190, 194; in aspergillosis, 198 Nigrospora, 321, 374 Nocardia, 10, 151, 154, 311, 320, 360-361; isolation from sputum, 402 Nocardia asteroides, 9, 131, 143-149, 361; and mycetoma, 152, 154, 158; eye infection, 273 Nocardia brasiliensis, 9, 17, 151, 361; and mycetoma, 153 f., 157 ff. Nocardia caviae, 152, 154 Nocardia madurae, 159 Nocardia pelletieri. See Streptomyces pelletieri Nocardia somaliensis, 159

426 Nocardiosis, 143-149 North American blastomycosis, 84-99; c u " taneous, 9, 11, 87-9«; immunology, 14, 17, 94-98; therapy, 22, 98-99; pulmonary, 88, 91; disseminated, 88-89, 9 1 ! compensable cases, 278 Nutrition: in deep mycosis therapy, 20; deficient, as factor in mycoses, 41, 151, 166 £., 181, 190, 194, 216 Nutrition of fungi, 293-296 Nystatin, 194, 203, 274

Index

Phycomycetes, 189, 191, 287 f., 309 f. Phycomycosis (mucormycosis), 14, 17, 41, 189-194, 273 Piedra, 264-267 Piedraia, 317 Piedraia hortai, 266, 337-338 Pimaricin, 44 Pityriasis versicolor tropica. See Tinea versicolor Pityrosporum, 253, 318, 340 Pityrosporum orbiculare, 255-256, 341 Pityrosporum ovale, 296, 340 f. Occupational hazard: fungi as, 275-278 Plenoiythia, 317, 338-339 Oedecephalum, 319, 349 Pleomorphism, 214, 299-300; avoiding, in Onycholysis, 168-170, 174, 176, 198, 227, cultures, 398 Pleospora, 317, 337 270; industrially caused, 276 Pneumoconiosis, 198 Onychomycosis, 198, 227-228 Oogonium, 287-288 Polyps, nasal: in rhinosporidiosis, 205 ff. Oomycetes, 287 Potassium depletion: in amphotericin B Oospores, 288 therapy, 22 Oral candidiasis, 167 Potassium iodide therapy, 60-61, 98, 186, Oral thrush, 170 194. ¡>03 Orbit, 134, 191, 200, 273 Potassium permanganate: tinea pedum and Otomycosis, 268 manuum, 243 Precipitin reaction: with coccidioidin, 16, Paecilomyces, 319, 352 39; in histoplasmosis, 18, 74, 77; sporoPapularia, 321, 373-374 trichosis, 59 f.; S. American blastomycoParacoccidioides brasiliensis. See Blastosis, 106-107; actinomycosis, 139; mycemyces brasiliensis toma, 158 Paracoccidioidomycosis. See South Amer- Prediabetic diathesis, 174-175 ican blastomycosis Pregnancy: and coccidioidomycosis, 41 f.; Paraphyses, 290 and moniliasis, 167 f. Pansexuality, 299 Prosenchyma, 283 Parasitism in plants, 294-295; dimorphism, Pseudoepitheliomatous hyperplasia, 55, 91, 300-301 104, 171 Parathyroid disease: and moniliasis, 233 Pseudoparenchyma, 283 Paronychia, 168-169, 174, 176, 227, 270, Puccinia graminis, 294 276 Pullularia, 321 Penicillin: for actinomycosis, 20, 140; pro- Pullularia pullulans, 372, 378 motes sporotrichosis, 62; in nocardiosis, Pulmonary focus: dissemination from, in 149; pretreating sputum cultures, 401 deep mycoses, 11, 67, 85, 90 Pencillium, 156, 310, 316, 319, 351-352 Pulmonary involvement: in coccidioidomyPenicillium griseofulvum, 239 cosis, 27 ff., 41; in histoplasmosis, 65-66, Perianal moniliasis, 168 68 ff., 77 f.; in blastomycosis, 85, 87 f., Perifollicular granulomas, 226 ff. 91. 95-96, 97, 99; in S. American blastoPerithecium, 290 mycosis, 103 f.; in cryptococcosis, 114Perleche, 167, 173 115, 120, 122; in nocardiosis, 145, 147; in Peronosporaceae, 294 moniliasis, 170-171 Phialophora, 183 f., 321, 374, 376 Pycnidium, 286 f. Phialophora (Cladosporium, formerly HOT- Pyrenomycetes, 290 modendrum) pedrosoi, 184 Philaphora compactum, 184 Reproduction of fungi, 283-291 Phialophora dermatitidis, 184 Reticuloendothelial system: disease of, acPhialophora jeanselmei, 376-377 companying mycoses, 41; H. capsulatum Phialophora pedrosoi, 375 prefers, 64, 66, 71 ff., 75 Phialophora verrucosa, 180 f., 184, 285, Rhinosporidiosis, 205-209 Rhinosporidium seeberi, 205, 207 f., 295, 374-375 322 Phoma, 317, 338

Index Rhizoids, 193, 282 Rhizopus, 190, 193, 282, 288, 315, 324 Rhizopus arrhizus, 325 Rhizopus nigricans, 288, 324-325 Rhizopus oryzeae, 325—326 Rhodotorula, 318, 342 Ringworm. See Tinea barbae; Tinea capitis; Tinea cruris; Tinea pedum and manuum Rusts, 294, 310 Sabouraud's agars, 396, 399, 400, 401, 404, 405 Saccharomyces, 970, 316, 329 Saprolegnia, 287 f. Saprophytism, 293-294; dimorphism, 300 Sarcoidosis: and deep mycoses, 20, 71, 113 Sartorya, 316 Schizomycophyta, 309, 312 Schizosaccharomyces, 289 Sclerotium, 183, 283 Scopulariopsis, 319, 353 Sepedonium, 286, 320, 359 Septation, 282 Serologic tests, 15, 20, 30, 59, 88, 92, 106 Silicosis: with cryptococcosis, 113; with aspergillosis, 198 Skin: intracutaneous inoculation of fungi, 8-11; pigmentation of, and coccidioidomycosis, 32, 41; as portal of entry for mycoses, 49, 51, 136, 151; histoplasmotic lesions, 6911.; in N. American blastomycosis, 84-90 passim, 96-98; in S. American blastomycosis, 103; graft, for chromoblastomycosis, 186. See also Dermatophytes» Skin tests, 17, 19 i.; for coccidioidomycosis, 28 ff., 35, 38-39. 4°. 41-42> 44; i n sporotrichosis, 57-59, 61; in histoplasmosis, 68, 74, 76, 78; for N. American blastomycosis, 88, 92, 95, 98; for cryptococcosis, 121-124; in actinomycosis, 139; for mycetoma, 158; for candidiasis, 175 Soil: cultural isolation of organisms from, 402-404 Somatic structures of fungi, 281-283 South American blastomycosis (Paracoccidioidomycosis), 101-108; immunological resistance to, 14, 17, 106-107 Sporangiophore, 285 Sporangiospores, 284-285, 289 Sporangium, 189, 193, 284 f., 289 Spores, 283-291 Sporodochium, 286 f. Sporothrix. See Sporotrichum schenckii Sporotrichids, 58 Sporotrichins, 57-59, 61

427 Sporotrichosis, 10 f., 49-62; immunology, 14, 17, 57-60; therapy, 20, 22, 60-62 Sporotrichum, 285 Sporotrichum schenckii, 8, 10, 22, 37, 4962 passim, 354-355; and eye infection, 273; compensable disease, 277; dimorphism, 303-305 Stachybotrys, 321, 377 Stemphylium, 321, 381 Sterigma, 57, 285, 291 Sterigmatocystis, 156 Stilbamidine, 11, 98 Streptomyces, 10, 143, 154, 312, 320, 361362 Streptomyces madurae, 154, 362 Streptomyces natalensis, 44 Streptomyces nodosus, 21 Streptomyces paraguayensis, 155 Streptomyces pelletieri, 154, 362 Streptomyces primprina, 176 Streptomyces somaliensis, 154 Streptomycin: promotes sporotrichosis, 62; in nocardiosis, 149; in mycetoma, 159; pretreating cultures with, 401 Stroma, 283, 286 Stysanus, 322, 383 Sulfonamides, n , 20, 77, 107, 132, 149, 159 Surgery: in systemic mycoses, 41 f., 77-78, 98-99, 125, 149, 159; in intermediate mycoses, 186, 194, 209 Syncephalastrum, 315 Syncephalastrum racemosum, 327-328 Taloramyces, 316 Thallospores, 284 Thallus, 287 Thromboangiitis obliterans, 227 Thrombocytopenic purpura, 159 Thrombosis: and amphotericin B, 43; with phycomycosis, 194 Thrush, 165, 167, 170, 214 Tinea barbae, 221-222; therapy, 242 Tinea capitis, 216-221; black-dot variety, 219-221, 229; diagnosing, 228-229; and epidermal effluvial current, 234-235; immunity to, 235; and griseofulvin, 240, 241-242 Tinea corporis, 222, 229, 233; therapy, 242 Tinea cruris, 224, 235; treatment of, 240, 242 Tinea flava. See Tinea versicolor Tinea imbricata (tokelau), 223-224 Tinea nigra, 259-263 Tinea of the nails, 227—229 Tinea pedum and manuum, 225—227, 229, 235; therapy, 240, 243-245 Tinea versicolor, 252-258 Tokelau. See Tinea imbricata

428 Torulins, 123 Torulopsis, 317, 339-340 Torulopsis glabra, 339 Torulosis. See Cryptococcosis Trichoderma, 319, 348-349 Trichophytid, 236 Trichophytin reactions, 235—238 Trichophyton, 214 t., 286, 320, 363 Trichophyton concentricum, 223-224, 242, 366 Trichophyton equinum, 369 Trichophyton ferrugineum, 220-221, 367368 Trichophyton gallinae, 368-369 Trichophyton megninii, 368 Trichophyton mentagrophytes, 221 f., 224 f., 227, 233, 238, 364-365 Trichophyton rosaceum, 397 Trichophyton rubrum, 175, 224, 226 ff., 243, 245, 365; immunology, 231-232, 246; treatment, 240, 242, 244; and compensable disease, 276; culture study, 394, 397 Trichophyton schoenleinii, 220, 233, 367 Trichophyton terrestre, 331, 369 Trichophyton tonsurans (sulfureum, crateriforme), 215, 219 f., 241, 365-366 Trichophyton verrucosum, 222, 368 Trichophyton violaceum, 220, 241, 366367 Trichosporon, 266, 316, 345 Trichosporon beigelii, 266, 345 Trichothecium, 320 Trichothecium roseum, 362-363 Tuberculosis: and resistance to mycoses, 20; associated with histoplasmosis, 75;

Index causes phycomycosis, 190; as cause of aspergillosis, 197 ff. Ultraviolet radiation: filtered, in diagnosis, 219, 255, 269; and variants, 299 Uredinales, 294, 310 Ustilaginales, 294, 310 Ustilago, 310, 385 Vaccine therapy, 44, 61, 194 Vaginal infection: Candida, 172, 174 Variation in fungi, 297-299 Verticillium, 319, 353-354 Vitamins: for deep mycoses, 20, 41, 62; deficiencies favor candidiasis, 174; deficiency as cause of phycomycosis, 194 Vulvovaginal moniliasis, 168 Wheal response: to coccidioidin, 40; to trichophytin, 235-238 White piedra, 264-266 Woolly degeneration, 299 X-5079C, 22, 194 X-radiation: in sporotrichosis, 61; in actinomycosis, 140; factor in phycomycosis, 190; and variation of fungi, 299 Yeast cells: in Ascomycetes, 289; forming of, 301 Yeast extract agar, 402, 406 Zoospores, 284-285 Zygomycetes, 287-288 Zygorhynchus, 288 Zygospores, 288 f. Zygotes, 288 f.