546 PATHOGENIC FUNGI 



papillomatous appearance, with irregularly distributed pustule 

 formation, and surrounded by a reddened areola containing 

 numerous miliary abscesses. Areas of tbis 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 

 become 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 con- 

 dition of the cutis. Special features are the development of 

 minute pustules, partly intra-epithelial, 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 Eixford 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 granulomata 

 leading to ulceratibn with epithelial hyperplasia. This may 

 be the primary manifestation of the disease, but the internal 

 organs become affected with 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 

 of the organism and led to its being denominated oidium 

 coccidioides. 



The organisms isolated from these varying lesions are 

 evidently all closely allied, although probably not identical. 

 In blastomycetic dermatitis the organisms are present chiefly 

 in the abscesses in the corium and to a less extent in the more 

 superficial suppurations, and can be demonstrated by mounting 

 the pus in 30 per cent, caustic potash solution. They are 

 spherical in form, 8 to 10 yu, in diameter, and appear singly, in 

 pairs, or less frequently in larger groups (Fig. 172). There is 



