[Treatment of onychomycosis]

A positive mycological examination is required before discussion of treatment of onychomycosis. Onychomycosis is most commonly due to dermatophytes in association with tinea pedis and/or tinea manuum. It is a catched infection. Candida onychomycosis is a rare opportunistic infection and onychomycosis due to non-dermatophytic moulds is very rare as a "chance mishap". The treatment of dermatophyte onychomycosis takes each infected part of the nail into account. Topical antifungal agents should be reserved for mild to moderate onychomycosis. Systemic antifungal agents are required to severe onychomycosis. In all cases, removal of infected nail parts is useful to facilitate the penetration of antifungal drugs and eradication of reinfection sites may be done to prevent recurrences and relapses. In primary, Candida onychomycosis treatment with topical antifungal drugs may be effective but in case of treatment failure, a systemic therapy is required. Suppression predisposing factors is useful. The treatment of non-dermatophytic moulds onychomycosis is still a challenge. Except Neoscytalidium spp., which mimic a dermatophytosis, non-dermatophytic moulds may be isolated from dystrophic nails and it is always difficult to specify their role as a primary pathogen or as a colonizer of nails. The available topical and systemic antifungal drugs are not effective against these non-dermatophytic moulds except itraconazole for onychomycosis due to Aspergillus spp. New therapy such as light and laser therapy are in evaluation.