CHAPTEk VI 



Immunity and Cutaneous Sensitization 



1. THE TRICHOPHYTON TEST 



AT THE outset it should be mentioned that a most welcome method 

 1\, for the diagnosis of a fungous infection would be a test based on 

 specific acquired cutaneous sensitization to a fungus after infection. While 

 sensitization often occurs shortly after infection, it does not do so invariably, 

 and cutaneous tests based on the assumption that the phenomenon is con- 

 stant often cause confusion. Since sensitization may have been produced by 

 a previous infection, a test based on its demonstration cannot be regarded 

 as unqualifyingly diagnostic. An eruption which is caused by fungi or their 

 products and is due to cutaneous hypersensitivity is designated in this 

 book as dermatophytid. Further discussion of the subject will be found 

 on pages 58 and 116 to 119. 



Most of the work in this field has been done with trichophytin, made 

 from common dermatophytes. Oidiomycin, made from Monilia albicans, 

 has also been investigated, and coccidioidin and sporotrichin are said to 

 elicit specific reactions in patients infected with Coccidioides immitis and 

 Sporotrichum schencki, respectively. According to Martin and others, pa- 

 tients with blastomycosis may or may not react to an extract made from 

 Blastomyces dermatitidis. Negative reactions to the extract are always 

 found in normal individuals. 



Because of the controversial nature of the subject and because we 

 believe that knowledge of previous investigations of allergic and immuno- 

 logic phenomena relating to fungous disorders may assist in the develop- 

 ment of better methods of diagnosis and treatment, we have here reviewed 

 the literature somewhat more extensively than for some other subjects 

 treated in this work. 



(a) Review of the literature.— In 1902 Neisser and Plato made an 

 extract of fungi isolated from patients with ringworm and called the prod- 

 uct "trichophytin." They found that when this substance was administered 



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