Chronic dermatophytosis caused by Trichophyton rubrum.

We believe that patients are genetically predisposed to Trichophyton rubrum infections in a dominant autosomal pattern and that persons with distal subungual onychomycosis caused by T. rubrum invariably have preexisting T. rubrum tinea pedis of the soles. This relationship has many potentially important clinical implications with respect to diagnosis, treatment, and the prevention of reinfection.