Non-dermatophyte fungi in onychomycosis-Epidemiology and consequences for clinical practice.

Onychomycoses are difficult-to-treat fungal infections with a high recurrence rate that relates to the anatomic and pathophysiological conditions in the nail organ and the required extended duration of treatment. Clinical-epidemiological studies demonstrated that non-dermatophyte molds and yeasts are the primary causative agents in 20%-30% of onychomycoses. Mixed infections with dermatophytes are observed as well. Therefore, the causative agents should be determined by fungal culture and the antifungal treatment regimen should reliably cover non-dermatophytes, if appropriate. Systemic-topical combination therapy involving a broad-spectrum, locally applied antifungal may increase the mycological and clinical cure rates compared to monotherapy with systemic drugs.