Immunity and Cutaneous Sensitization ;>l 



any immediate response, whereas in the first group (with circulating anti- 

 bodies) there is no difference between the responses to the first and those 

 to a subsequent injection in the same site at various intervals between 

 the two. 



Our studies on this important subject of immediate wheal reactions have 

 not been completed, but it seems that some so-called negative reactions 

 may be attributed to a laek of observance of the immediate response. We 

 have so far noted the wheal reaction not only in cases of infection due to 

 T. purpureum but also in a few instances when only E. inguinale and T. 

 gypseum have been found on culture. We have also observed an immediate 

 wheal reaction to oidiomycin. In the cases in which there are no circulating 

 antibodies, the sensitized tissue appears to be situated in the upper cutis 

 with increased permeability of the capillaries of the skin. 



(e) Does a patient with a trichophytid always react to trichophy- 

 tin?— It is theoretically possible that the vaccine (trichophytin) may lack 

 some of the components of the living fungus which are capable of eliciting 

 reactions. However, in practice such an occurrence must be rare. If the 

 patient's skin is sensitized so that a trichophytid reaction is produced, it is 

 hardly likely that it will fail to react to the extract. We subscribe to the 

 principle that a positive reaction to trichophytin is requisite to a diagnosis 

 of dennatophytid. Some observers have reported negative reactions to 

 trichophytin in cases of typical dermatophytid. They state that they have 

 demonstrated anticutins to trichophytin to explain the anergic phase. In 



TABLE 6.— Reaction to Trichophytin Test of Patients with Eruption on Hands 

 and Feet for Whom Culture from Feet Yielded T. Gypseum 



Table 1 are listed the cases of trichophytid in which we are reasonably 

 certain that no other diagnosis could explain the rash. Our diagnosis was 

 based on an evident inflammatory focus preceding the eruption and was 

 proved by culture and by the subsequent development of vesicles which 

 were sterile for the growth of fungi. Irritation of the original focus some- 

 times caused an exacerbation of symptoms; the test dose of trichophytin 



