FUNGAL INFECTIONS (ONYCHOMYCOSIS)
When a nail infection develops, the most common cause is a fungus. More frequent on the toenails than on the fingernails, fungal nail infections affect about 12% of all Americans. Onychomycosis tends to run in families because of an inherited tendency, but not everyone is susceptible. It is rare in children unless one or both parents are infected.
The two most common types of fungi affecting the skin are dermatophytes and yeast (Candida). While both types infect nails, dermatophytes tend to be more common in toenails. Yeast infections are seen more frequently in fingernails and other areas of the skin. While some fungal nail infections may respond to topical antifungal creams, lotions, gels, and lacquers, most infections of the nail plate require oral medicines such as itraconazole, terbinafine, and fluconazole.