80 An Introduction to Medical Mycology 



infection ( dermatophytosis, tinea cruris) or secondary allergic eruptions 

 ( dermatophy tid ) . In many instances concomitant lesions will be found 

 in the scalp, the nails, the bearded area, the inguinal region or the feet. 

 A patient with an infection of the glabrous skin should be carefully exam- 

 ined for other foci. 



(a) Etiology.— One of a number of different organisms may be found. 

 The commonest is M. lanosum. The infection may be caught from a kitten 

 or other pet, a playmate or another member of the household. Finding the 

 source of infection here is usually comparatively simple. In other instances 

 infection may be due to A. sehoenleini, the condition almost always being 

 secondary to an infection of the scalp; to T. gypseum, in which case the 

 infection may have been caught from an animal, from a focus on the pa- 

 tient's feet or from another person, or to T. purpureum, the lesion in this 

 instance almost always being part of a syndrome involving the nails and 

 feet. During two years (1943 to 1945) we observed 18 cases of tinea of the 

 nonhairy skin due to M. audouini, indicating that tinea glabrosa due to 

 this fungus is more common than was formerly thought. There are a few T 

 other organisms which may at times produce eruptions on the smooth 

 skin, but they are relatively unimportant. While these manifestations may 

 appear at any age, children are particularly prone to exhibit circinate lesions 

 due to M. lanosum. Adults, on the other hand, show a preponderance of 

 infections due to the other organisms. Women occasionally become in- 

 fected from their children or from new pets (kittens). One of the most 

 obstinate cases of tinea glabrosa in our experience was that of a woman 

 on whom developed over 100 circinate lesions and in whom the thera- 

 peutic response to various types of treatment was poor. 



(b) Clinical types.— (i ) Tinea circinata (M. lanosum and M. audouini). 

 —The classic form of ringworm is evidenced by an erythematous ringed 

 lesion gradually increasing to a diameter not over 6 in. (15 cm.). There 

 are usually minute vesicles along the border; the surface is scab - , and the 

 center appears unaffected. Sometimes two or more concentric rings may 

 appear in a single lesion. If the condition is untreated, new lesions develop 

 on skin adjacent to or remote from the original focus. The lesions are com- 

 monly seen on the faces or necks of children with tinea capitis; while the 

 infection is commonly due to M. lanosum, we have recently seen more 

 cases than usual of tinea circinata due to M. audouini. The backs of the 

 hands and other exposed parts arc the usual sites of the first lesions in pa- 

 tients who catch the infection from an outside source. Ringed lesions are 

 sometimes caused by T. purpureum. The subjective symptoms are usual!) 

 mild, although the infection is itchy and subsequent scratching may con- 

 tribute to its spread. 



