[Modern mycologic diagnosis. Problems in the daily practice].

Mycological diagnosis is an integral part of dermatology. Modern aspect include not only the identification of causative agents but also sensitivity testing against topical and systemic antimycotic agents and more detailed molecular biological diagnosis using fingerprinting and PCR. In routine practice, the essential question is if a fungal infection is present or not. A positive culture identification should precede use of systemic antimycotic agents especially when dealing with advanced onychomycosis, tinea capitis and chronic candidosis. Determination of resistance is important when dealing with recurrent infections with special candidal species. PCR is most useful in diagnosing otherwise difficult to identify causative agents and in analyzing the chain of infection.