30 An Introduction to Medical Mycology 



fungous infections. It is here shown that a patient with a severe infection 

 may yield a negative response to trichophytin. When the infecting organism 

 is T. purpureum or A. schoenleini, for example, there is little likelihood of 

 cutaneous sensitization and response to therapy is usually poor. Another 



TABLE 4.-Reaction to Trichophytin, after 48 Hours, of 254 Patients with 



Proved Fungous Infection 



Fungus 

 M. lanosum . . . . 

 M. audouini . . . 

 A. schoenleini . 

 T. purpureum . 

 T. gypseum . . . 

 T. violaceum . . 

 M . f ulvum .... 

 T. niveum 



E. cruris 



T. crateriforme . 



No. 



OF 



Cases 



No. of 

 Negative 

 Reactions 



O 



No. of 



Positive 



Reactions 



+ 



+ + 



+ + + 



Percentage 

 of Positive 

 Reactions 



39 



48 



10 



50 



88 



6 



4 



4 



3 



2 



4 

 18 



7 

 25 

 13 



3 



1 

 1 



5 

 15 



1 

 13 

 12 



15 



8 

 2 

 8 

 35 

 2 

 1 



1 



1 



14 



7 



2 

 23 

 1 

 2 

 3 



1 



76 

 31 

 20 

 24 

 71 

 50 

 75 

 75 

 33 

 100 



possibility is that in a case of recent infection the test may be undertaken 

 before sensitization has occurred. In experimental work, the time necessary 

 for sensitization may vary between one and two weeks. 



We have found that approximately 53 per cent of patients with infec- 

 tions due to T. purpureum who exhibited negative reactions according to 



TABLE 5.— Comparison of Immediate and Delayed Reactions to Trichophytin 

 for Three Species of Infecting Micro-Organisms 



examination of the test site after 48 hours showed a positive response when 

 the site was examined 10 minutes after the test. An additional 32 per cent 

 of patients reacted both after 10 minutes and after 48 hours (Table 5). 

 In some instances this immediate wheal reaction is associated with circu- 

 lating antibodies, as evidenced by passive transfer tests. In the other cases 

 we are unable to demonstrate circulating antibodies. It is interesting that 

 in the latter cases a second injection into the site of the first fails to elicit 



