[Diagnosing and treating of onychomycosis].

Onychomycosis is a frequent disorder, which accounts for approximately 50% of nail changes. Many patients are treated for onychomycosis without a mycological verification being done. The patients may be in risk of being treated for a non-existent fungal infection with lack of effect and potential adverse events. This review highlights the importance of choosing the correct sampling and diagnostic methods, as genus and/or species identification is essential when choosing the optimal treatment strategies.