PARASITIC GROWTH PHASE 181 



ulomatous in nature, there being much new-formed connective tissue 

 and considerable infiltration with mononuclear leucocytes. Giant 

 cells may be formed, and the epithelial tissue, in response to irrita- 

 tion, undergoes considerable proliferation and may send long, finger- 

 like processes down into the inflammatory tissue, much as in epitheli- 

 oma. A very constant and characteristic feature of the microscopic 

 pathology is the occurrence of minute abscesses, i.e., spaces filled with 

 polymorphonuclear leucocytes, in the epithelium proper. In these 

 miliary abscesses the parasites are found extracellularly and within 

 giant cells. Baker ^ has recently analyzed the tissue reactions in 

 twenty-three cases. 



Diagnosis. The diagnosis of blastomycosis is made by the demon- 

 stration of the fungus in tissues or pus. This is necessary because of 

 the similarity of the lesions to those of other granulomatous proc- 

 esses. The size of the fungus makes it relatively easy to find in 

 tissue sections or when pus is mixed with a drop of 10 per cent 

 sodium hydroxide and examined unstained under a cover slip. 

 Martin described a complement-fixation test which appeared to be 

 specific. However, a negative test does not exclude the diagnosis 

 because complement-fixing antibodies are absent from the blood in 

 some cases. 



Treatment and Prognosis. In the treatment of cutaneous blasto- 

 mycosis sodium iodide intravenously and potassium iodide by mouth 

 have been fairly successful. Tincture of iodine is also applied locally. 

 Currettage of the lesions and x-ray therapy as well as radium have 

 also cured some cases. Occasionally no treatment is effective. 



In systemic blastomycosis iodides not only fail to arrest the dis- 

 ease but may cause a rapid spread of the lesions. Martin and Smith ^ 

 recommend partially desensitizing the patient by injecting subreact- 

 ing doses of a skin-testing material prepared from the fungus and 

 gradually increasing the dose until little or no reaction is elicited. 

 Iodides can then be safely administered and sometimes they cure 

 the infection. The prognosis in systemic blastomycosis, however, 

 remains extremely bad. 



Parasitic Growth Phase. Cells of the parasitic growth phase vary 

 from 3 to 24 microns in size, the usual range being 8 to 10 microns. 

 The fungus cell has a thick wall which is sometimes described by 

 the rather ambiguous term, double contoured, because its inner and 

 outer limits can be observed. The cell may bud in a manner re- 

 sembling that of the yeasts or it may elongate or become dumb-bell- 

 shaped and be divided by a crosswall at the point of constriction. 

 When a bud is formed it at first has a thinner wall than the parent 



