Failure of treatment in chronic dermatophyte infections.

A proportion of dermatophyte infections fail to respond to normally adequate courses of griseofulvin and topical antifungal therapy. The organism Trichophyton rubrum was isolated from 96% of 50 patients studied, but no instances of in vitro resistance were seen. Of these patients, 57% had an underlying condition, commonly hay fever/asthma, atopic eczema, collagen disease or ichthyosis. Defective delayed type hypersensitivity responses and leucocyte migration inhibition to the specific antigen, trichophytin, were demonstrated. Immediate type hypersensitivity was seen in 58% and this was partially suppressible with chlorpheniramine and cimetidine. The relationship between these abnormalities and failure of treatment is discussed.