The Superficial Mycoses 119 



investigation point to dermatophytid, possible sensitization from external 

 contacts should be considered, and patch testing with suspected sub- 

 stances is always in order. 



The same type ot vesicular dermatophytid which appears on the hands 

 may also be found on the feet, particularly on the soles. Here, as on the 

 hands, examination for fungi may yield negative findings. 



The condition known as keratolysis exfoliativa was studied by MacKee 

 and Lewis, who considered that it is often a form of dermatophytid. They 

 found that it frequently occurred in patients who had an active mycosis of 

 the feet and that vesicular dermatophytids were commonly present. In 

 keratolysis exfoliativa the lesions consist of superficial scaly macules, which 

 may coalesce and are localized to the palms and/or soles. The lesions 

 at first are unruptured empty vesicles. The scale is as thin as cigaret paper. 

 When it is broken, collarets are formed at the edges. Only a few lesions may 

 develop, or most of the skin on the palms and soles may be affected. The 

 almost constant presence of the mosaic fungus is considered significant. 



Another type of dermatophytid occurring on the legs has been described 

 as erysipelas-like. It appears to be proved that in some of the reported cases 

 secondary allergic lesions arose from a focus on the interdigital webs of 

 the feet. In other cases, little proof was offered that the lesions were not 

 in reality of streptococcic origin. In several instances of eruptions of this 

 character, with localized erythema and swelling and sometimes with fever 

 and prostration, fungi were demonstrated in scrapings from the feet. The 

 trichophytin test, however, did not elicit a positive reaction in every case, 

 even when a site near the lesion was tested. Furthermore, in a number of 

 instances bacteriologic studies revealed the presence of streptococci. Fur- 

 ther study appears to be necessary to prove beyond doubt that in all or in 

 most of these cases the condition is entirely due to the dissemination of 

 fungi from the focus on the feet. 



•"Moreover, it must not be forgotten that many lesions at points remote 

 from the initial infection are due to external dissemination of fungi. These 

 lesions are not dermatophytids and certainly should not be classed as such. 



(g) Histology.— The findings vary according to the infecting micro- 

 organism. 



(I) Acute injection— The changes in acute dermatophytosis are similar 

 to those observed in acute eczematous eruptions. The stratum corneum 

 shows some parakeratosis. Small vesicles are to be seen below this layer. 

 The intensity of the process determines the degree and extent of vascular 

 dilatation, of edema and of round cell infiltration in the upper cutis. In 

 other words, there is a superficial exudative inflammatory process with 

 some epidermal (eczematous) changes. 



