Dermatophytid--a misdiagnosed entity?

A mycological and immunological survey was performed in 26 patients with clinical signs of dermatophytid. Only 10 patients fulfilled the main criteria of dermatophytid reactions, i.e. positive delayed skin test to trichophytin and dermatophyte isolated by culture. Trichophyton mentagrophytes--especially the zoophilic variant--was found in 9 patients of 10. In the majority of cases, inflammatory tinea pedis caused the dermatophytid reaction which appeared as vesicles localized to the palms. Relying on clinical appearance only implies an obvious risk of erroneously including pyoderma and various eczemas, e.g. pompholyx and contact dermatitis, as dermatophytids. Mycological culture and skin test with a reliable trichophytin antigen preparation ought to be applied in order to avoid misdiagnosis.