Relapsing severe Trichophyton rubrum infections in an immunocompromised host: evidence of onychomycosis as a source of reinfection based on lectin typing.

A 64-year-old patient developed recurrent (about 3-6 times a year) generalized skin lesions due to Trichophyton rubrum during long-term steroid treatment of lung fibrosis. Additionally, he suffered for years from onychomycosis of all toes. In the past, short-term internal treatment with griseofulvin and ketoconazole resulted in fast clearing of skin symptoms. Since 1991 relapses have been treated with itraconazole orally. In 1992 material was collected from diseased nails and toe and other skin lesions during three severe attacks of fungal infections and in addition once from toenails during a period without skin manifestations. Trichophyton rubrum was isolated from each sample. Lectin typing of the isolates using five lectins of plant origin resulted in identical lectin patterns for all isolates, thus localizing the toenails as the source of reinfection. The results indicate that lectin typing may play an important role in clinical and epidemiological analysis of dermatophytes.