Onychomycosis: rationalization of topical treatment.

BACKGROUND Fungal infection of the nail affects millions of people worldwide and has an estimated prevalence of more than 10% of the general population. OBJECTIVES To determinate the prevalence of fungal infection in toenails, in order to decide the treatment policy for onychomycosis. METHODS We evaluated 331 patients with suspected clinical toenail onychomycosis affecting at least two toenails. Mycological examination of the affected nails was performed; both the KOH test and fungal culture were used. RESULTS Of 331 patients with suspected clinical toenail onychomycosis, 78.2% of the patients had at least three infected nails. The first toenail was the most affected. Trichophyton rubrum was by far the most common dermatophyte cultured from all samples. CONCLUSIONS Most of the patients had at least three affected toenails. Topical treatment is not effective or practical, and systemic treatment should therefore be considered.