Epidemiology and clinical classification of onychomycosis.

Objectives  To review recent data – what is new in the epidemiology of onychomycoses? To identify the most relevant diagnostic criteria for effective therapy. Methods  The preliminary results of the European Onychomycosis Observatory (EUROO) study were analysed. In this international study, physicians completed questionnaires concerning patient profile and the disease. Results  One of the most interesting novel findings was that sampling requests were often not made [only 3.4% of general physicians (GPs) and 39.6% of dermatologists]. This means that no information about causative agent(s) was available, hindering appropriate treatment choice. Furthermore, contrary to previous findings, 70.7% of participants did not practice sports. Lastly, these preliminary findings showed that treatment strategy depends largely on the type of treating physician, with GPs preferring monotherapy and dermatologists preferring combination therapy. Conclusions  A consensus was reached that treatment strategy should depend on the severity of nail involvement and the causative fungus. It is thus important to promote the importance of sampling. To simplify the choice of an appropriate treatment, onychomycosis may be divided into just two clinical groups: onychomycosis with and without nail matrix area involvement. However, the distinct clinical findings (number and type of affected nails, multimorbidity, drug interaction, etc.) in each individual case must be taken into account to ensure an appropriate treatment decision.