Onychomycosis, also known as tinea unguium, is a fungal infection of the nail. Symptoms may include white or yellow nail discoloration, thickening of the nail, and separation of the nail from the nail bed. Toenails or fingernails may be affected, but it is more common for toenails. Complications may include cellulitis of the lower leg. A number of different types of fungus can cause onychomycosis, including dermatophytes and Fusarium. Risk factors include athlete's foot, other nail diseases, exposure to someone with the condition, peripheral vascular disease, and poor immune function. The diagnosis is generally suspected based on the appearance and confirmed by laboratory testing.
|Other names||Dermatophytic onychomycosis tinea unguium|
|A toenail affected by onychomycosis|
|Symptoms||White or yellow nail discoloration, thickening of the nail|
|Complications||Lower leg cellulitis|
|Usual onset||Older males|
|Risk factors||Athlete's foot, other nail diseases, exposure to someone with the condition, peripheral vascular disease, poor immune function|
|Diagnostic method||Based on appearance, confirmed by laboratory testing|
|Differential diagnosis||Psoriasis, chronic dermatitis, chronic paronychia, nail trauma|
|Treatment||None, anti-fungal medication, trimming the nails|
|Frequency||~10% of adults|
Onychomycosis does not necessarily require treatment. The antifungal medication terbinafine taken by mouth appears to be the most effective but is associated with liver problems. Trimming the affected nails when on treatment also appears useful.
There is a ciclopirox-containing nail polish, but there is no evidence that it works. The condition returns in up to half of cases following treatment. Not using old shoes after treatment may decrease the risk of recurrence.
Onychomycosis occurs in about 10 percent of the adult population, with older people more frequently affected. Males are affected more often than females. Onychomycosis represents about half of nail disease. It was first determined to be the result of a fungal infection in 1853 by Georg Meissner.