84 An Introduction to Medical Mycology 



(2) Eczematous type.— There are two forms, primary and secondary. In 

 the first, the initial response to infection ( usually T. gypsemn ) is a vesicle, 

 and vesicles continue to form, rupture and become crusted. The infection 

 spreads peripherally; the lesion may remain ill-defined or become circulate, 

 with active vesiculation along the periphery. There is no tendency to cen- 

 tral clearing. Lesions are commonly solitary and rarely numerous. In- 

 cluded here is favus herpeticus, a rare manifestation of favus. The markedly 

 inflammatory and rapidly spreading eruption due to Trichophyton alba 

 may also be mentioned as an uncommon form. The secondary form of 

 eczematous patch is caused by sensitization to applied medicaments or by 

 treatment producing primary irritation, which transforms a circulate lesion 

 into a vesicular, oozing patch. 



(.3) Scaly type.— A small area of ill-defined branny scaling with slight 

 redness at the base may be the only manifestation of A. schoenleini or 

 of one of the endothrix Trichophyta, such as T. violaceum. Trichophyton 

 purpureum also causes such a lesion, but usually more typical areas are 

 present in addition. Microscopic and cultural studies are necessary for 

 differential diagnosis. 



(4) Crusted type.— Favus of the glabrous skin may manifest itself by 

 the formation of scutula similar to the cup-shaped crusted lesions com- 

 monly noted with the scaly type. Crusts may be formed by the drying of an 

 exuding surface, particularly if the lesions are eczematous, but there is 

 much more inflammatory reaction than is associated with favus. 



(5) Solid plaque type.— Trichophyton purpureum is the cause of lesions 

 which are not unlike certain lesions of psoriasis, being dull red and scaly 

 on the surface, with slight thickening. Bleeding points are usually not 

 present when the scales are removed. The intensity of the color may vary in 

 different portions of a single patch. The shape of the lesions is not neces- 

 sarily regular. The size of the patches varies from that of a pinhead to that 

 of a half-dollar or larger. There is no tendency to central clearing. Lesions 

 have been noted on various portions of the trunk, on the extremities and, 

 in a single instance, on the face. 



(6) Bizarre and configurate type— -In this type, T. purpureum is the 

 cause of an eruption which may involve large surfaces of skin of the trunk. 

 The infection begins at one or more points and migrates in a thin line over 

 an ever-widening area. The affected skin is dull red and shows slight infiltra- 

 tion and scaling on the surface. Behind the advancing border the skin is 

 lighter than normal. This suggests partial achromia. Persistent itching is 

 a constant feature, and excoriations are usually seen. 



(7) Tinea imbricata-like type— Kittrcdge described a widespread scab 



