194 An Introduction to Medical Mycology 



(7) Allergic lesions.— Sporotrichids, comparable to trichophytids, have 

 been described by de Beurmann. 



(d) Histology.— D. L. Satenstein's description of a section removed 

 from the edge of an ulcerating lesion is fairly typical of the usual observa- 

 tions: 



The epidermis is irregularly acanthotic The greater part of the cutis is filled with a 

 dense cellular infiltrate. The blood vessels are markedly dilated, some approaching 

 the size of sinuses. Scattered throughout the cellular infiltrate are many very small 

 blood vessels. The cellular infiltrate is composed of a great many mast cells, some con- 

 nective tissue cells and a few plasma cells, and in the central portion there is a large 

 group of giant and epithelioid cells. There are also many polymorphonuclear cells 

 scattered throughout the entire zone. There is no degeneration and no abscess forma- 

 tion. The whole process is one of organizing granulomatous tissue with enormous 

 numbers of mast cells. No fungous elements are noted in routine sections, in those 

 stained by Gram's method or in those stained with polychrome methylene blue. 



The picture is not in itself diagnostic. One can determine that the process 

 is granulomatous, but syphilis, tuberculosis and other deep mycoses may be 

 difficult to differentiate. It should be remembered that S. schencki is seldom 

 observed in tissue, in contrast to the readily demonstrated presence of most 

 other pathogenic fungi. 



(e) Immune reactions.— An agglutination reaction may usually be dem- 

 onstrated (de Beurmann; Moore and Davis). Du Toit found that serum 

 of patients brought about agglutination in a titer of about 1:600. How- 

 ever, the spores were similarly agglutinated by the serum of normal con- 

 trols, thus nullifying the value of the test. The complement fixation test is 

 unreliable. According to Bloch, the intracutaneous test with an extract of 

 Sporotrichum is of value; de Beurmann expressed the opinion that a nega- 

 tive reaction rules out the diagnosis of sporotrichosis; there may occasion- 

 ally be a false positive reaction. Du Toit agrees that a positive skin reaction 

 occurs with regularity in patients with sporotrichosis. In the experimental 

 production of sporotrichosis in a volunteer, the response developed the fifth 

 day following inoculation. 



(f ) Differential diagnosis.— A positive laboratory diagnosis may usually 

 be made without difficulty from cultural studies. The micro-organism is 

 difficult to demonstrate in fresh preparations. 



The initial lesion, or sporotrichotic chancre, usually develops on the 

 fingers or hand. When lesions successively appear along the course of a 

 lymphatic chain, the clinical diagnosis may be highly suggestive. Before 

 secondary lesions have developed or if the initial lesion is in an atypical 

 location, the correct diagnosis may not even be considered. The character 

 of the lesions suggests a granuloma, and the differential diagnosis should 



