Superficial fungal infection of the skin. Where and how it appears help determine therapy.

Superficial fungal infections of the skin are a common presentation in clinical practice. Any skin surface, the mucous membranes, nail plates, and nail beds can be affected. Tinea pedis is the most common fungal infection and may affect up to 70% of the adult population worldwide. Ubiquitous candidal organisms are found in the oral flora of many healthy persons and result in infection in the presence of certain host factors or immunodeficiency disorders. Onychomycosis has had an increasing incidence worldwide, and it now accounts for almost half of all nail disorders. These and many other infections can have varying presentations as well as features that resemble nonfungal disorders. Therefore, it is important that primary care physicians are familiar with the many cutaneous fungal infections and their differential diagnosis to ensure that appropriate therapy is selected.