Diagnosis, clinical implications, and complications of onychomycosis.

The diagnosis of onychomycosis is suggested by the clinical presentation as well as the family history and patient age. The definitive diagnosis of onychomycosis is based on (1) establishing the presence or absence of fungal elements using laboratory methods and/or (2) identifying the fungus using fungal culture or, in the future, by polymerase chain reaction as new developments emerge in this technology, making more widespread application of this technique possible.