Precipitating antibodies in dermatophytosis demonstrated by crossed immunoelectrophoresis

A total of 289 serum specimens from 262 patients with dermatophytosis were studied, using crossed immunoelectrophoresis with an intermediate gel. Rabbit antidermatophyte antisera were used as reference, and the antigens were water soluble extracts of Trichophyton (T) rubrum, T. mentagrophytes, Microsporum (M.) canis or Epidermophyton (E.) floccosum. Each serum was tested against the dermatophyte antigen corresponding to the infectious agent of the patient in question. Antidermatophyte antibodies could be demonstrated in 25 (9.5%) of the patients, and these were particularly frequent in patients with highly inflammatory lesions and those with chronic dermatophytosis caused by T. rubrum. Antibodies were detected in all four patients with kerion Celsi. Nine patients, five with acute dermatophytosis and four with chronic disease, who had precipitating antibodies at the initial examination were studied several times during the course of the disease. While the antibodies disappeared in all the patients with acute disease, they persisted in those with chronic dermatophytosis. The human antibodies showed marked cross reactivity with T. rubrum, T. mentagrophytes, M. canis and E. floccosum.