New fungal nail infections.

URPOSE OF REVIEW: The number of people affected by onychomycosis continues to increase. The prevalence of different pathogens in different areas depends on several factors, such as climate, geography and migration. We reviewed the recent literature to identify new agents responsible for onychomycosis. RECENT FINDINGS: Recent studies performed in different countries are not only reporting molds and yeasts as contaminants, but are increasingly reporting them as pathogens. Infection by novel agents is also being reported, although the individual cases do not necessarily indicate that these are emerging agents. SUMMARY: Clinicians should bear in mind the increased number of case series reporting the role of molds and yeasts in onychomycosis, and should not treat the disease without first examining the mycology results. The question remains as to whether these agents are truly new fungi responsible for onychomycosis, or whether improvement of diagnostic techniques and increasing reference to such species in the literature has resulted in better identification of such agents.