32 An Introduction to Medical Mycology 



always elicited a response (usually strong) and sometimes caused a focal 

 reaction. In Table 6 are listed cases in which cultures of T. gypseum were 

 isolated from the feet by culture and in which there was a concomitant 

 eruption on the hands. Although some of these rashes were considered non- 

 mvcotic, it is interesting that in 87 per cent of the cases the test with 

 trichophytin showed a positive reaction. 



(f) Variations in reactivity to trichophytin according to clin- 

 ical type.— We find no difference in the reactivity of the skin to tricho- 

 phytin between cases of inflammatory infections without evidence of 

 trichophytid and cases of trichophytid. In all instances the patients react 

 to the test. Likewise, all patients with acute tinea pedis due to T. gypseum 



TABLE 7.— Reaction to Trichophytin Test of Patients with Eruption on Feet 

 for Whom Culture Yielded T. Gypseum 



have positive reactions. The reaction to trichophytin in patients with 

 infection of the feet due to T. gypseum is shown in Table 7. Only 60 per 

 cent of these patients showed hypersensitivity to trichophytin. In the 

 patients with infection due to T. gypseum but with a negative reaction to 

 trichophytin either the cutaneous manifestation was a slightly inflammatory 

 focus or the organism was isolated from an infected nail. We conclude, 

 therefore, that some factor or factors are responsible for a trichophytid 

 other than infection with a potentially sensitizing organism. Some of 

 the factors which may precipitate a trichophytid are (1) heat, (2) severe 

 trauma (to hands), (3) intense anxiety and (4) administration of penicil- 

 lin. That a patient exhibits a positive reaction to trichophytin does not 

 necessarily mean that a trichophytid will develop. 



(g) "False" positive reactions.— We have not been able to confirm the 

 statement of Tolmach and Traub that a false positive reaction may follow 

 if one test site receives more than one test dose of trichophytin. To 10 

 patients who were not reactive to trichophytin, from two to five injections 

 of trichophytin were administered at the same site at intervals of from 

 two days to two weeks without evidence in any case of the development of 



