[Management of onychomycosis].

Onychomycosis accounts for half of all nail pathologies. Never prescribe a local or a systemic antifungal without confirmation of the diagnosis. The quality of the sampling is the cornerstone of mycological analysis. If the results of the mycology are negative, do not hesitate to harvest a new specimen if the clinical features are highly suggestive. Otherwise, think to another cause. Identify the clinical presentations at high risk of failure to classical treatments (thick hyperkeratosis, onycholysis, lateral disease, yellow spikes, moulds). Always eradicate as much as possible of the infected keratin (mechanically, chemically or surgically). A mycologic cure means a return to a complete normal nail with a negative culture. Prevent recurrences.