BLASTOMYCOSIS 549 



suggestive of protozoal characteristics and, while a mycelial 

 formation is stated to have been observed to originate from 

 them, we consider that their nature is not yet fully eluci- 

 dated. They have been observed in two disease manifestations 

 which we may now describe. The first of these is the blastomy- 

 cetic dermatitis, widely studied in America and especially in 

 Chicago. The disease may arise in any part of the skin and 

 frequently follows a slight wound. The development of a 

 sluggish papule, becoming pustular and ulcerative, is followed 

 by a slowly extending granular and papillomatous appearance, 

 with irregularly distributed pustule formation; and surrounded 

 by a reddened areola containing numerous miliary abscesses. 

 Areas of this kind, several inches in diameter, may slowly 

 develop. These may heal at one margin and extend widely at 

 another. The process may go on for years, and various, it may 

 be distant, parts of the skin may becomg successively affected. 

 In the great majority of cases no general disturbance occurs. 

 Microscopically, in the fully advanced stage, the picture is that 

 of an irregular epithelial proliferation and hyperkeratosis with 

 superficial papillomatous excrescences, and more deeply of a 

 similar irregular and free epithelial proliferation taking place in 

 a granulomatous condition of the cutis. Special features are 

 the development of minute pustules, partly intraepithelial, 

 partly in the corium, and the formation of giant cells, probably 

 of epithelial origin. In the pus, organisms presently to be 

 described are found. The characteristics of blastomycetic 

 dermatitis are its chronic nature and its restriction to the 

 skin. 



A closely allied condition is that described by Wernicke in 

 South America and by Kixford and Gilchrist in California. 

 In the first described cases attention was directed to the appear- 

 ance of suppurative conditions in the lungs. A skin lesion also 

 occurs, characterised by subcutaneous abscesses or gjanulomata 

 leading to ulceration with epithelial hyperplasia. This may 

 be the primary manifestation of the disease, but the internal 

 organs become affected wijh chronic suppurative processes or 

 granulomata, and death occurs. Cases belonging to the same 

 class are also recorded where subcutaneous nodules, consist- 

 ing of myxomatous connective tissue, have been observed 

 associated with the occurrence of suppurations in the internal 

 organs. The cases of generalised infection were at first 

 attributed to protozoa. The direct observation, under the 

 microscope, of the growth of a mycelium from the proto- 

 zoon-like body is the evidence adduced for the fungoid nature 



