Immunity <m<l Cutaneous Sensitization 23 



criminately but most showed a selectivity ol response. They Found thai 

 boiling had qo effect on the potency of trichophytin (thermostability). In 

 a group or unselected subjects, those who gave a negative reaction to 



tuberculin also tailed to react to trichophytin. In some of the cases in 

 which then 1 were negative reactions to trichophytin, however, positive 

 reactions to old tuberculin were produced. Otherwise no correlation be- 

 tween the 1 two allergens was noted. Intradermal injection of trichophytin 

 over the site of a subcutaneous injection elicited a stronger reaction than 

 intradermal injection alone. The presence of phenol in the amount usually 

 added as a preservative had no influence on the local reactions to any of 

 the antigens used. 



Robinson and Grauer pointed out that a given eruption is not necessarily 

 proved to be of fungous origin because the trichophytin reaction is positive. 

 They also observed a number of cases of mycotic infection in which the 

 reaction was negative. This finding was in agreement with the findings of 

 others. A possible source of error in the work of Robinson and Grauer was 

 that many of the fungi which they considered the cause of infection were 

 common laboratory contaminants and as such not usually considered of 

 pathogenic significance. 



Tomlinson obtained uniform reactions after the use of various kinds 

 and mixtures of trichophytin. Sulzberger, Lewis and Wise in a comparison 

 of three tvpes of commercial trichophytin found a fairly uniform response 

 to their use. There was, however, no correlation in number or degree be- 

 tween reactions to trichophytin and reactions to oidiomycin, showing that 

 Trichophyton and Monilia belong to different immunologic groups of 

 fungi, each capable of producing its independent specific hypersensitivity. 

 Peck stated that a positive reaction to trichophytin must be present before 

 a diagnosis of trichophytid may be determined. Traub disagreed with 

 Peck, stating that he had observed cases of typical dermatophytid in 

 which reactions to trichophytin were negative. Traub and Tolmach had 

 previously expressed their lack of confidence in trichophytin as a diagnostic 

 or therapeutic aid, doubting its specificity. They found no relation between 

 the severity of the infection and the cutaneous responses to injections of 

 trichophytin. In seven cases in which there were demonstrable fungi on 

 the feet and vesicular or squamous lesions on the hands, which they called 

 epidermophytid, negative responses to trichophytin were obtained. 



Knierer concluded from cutaneous tests of 115 persons that trichophytin 

 has some diagnostic value provided it is employed with due criticism. 

 He found the reaction to be positive in 10 to 35 per cent of persons free 

 from mycotic disorders and negative in 25 to 45 per cent of patients who 

 had a mycosis. 



