Fungal nail infection

Alternative names:

infection - fungal (nails); nails - fungal infection; onychomycosis

Definition:

An infection of the nails by a fungus.

Causes, incidence, and risk factors:

The body normally hosts a variety of microorganisms, including bacteria and fungi. Some of these are useful to the body. Others may multiply rapidly and form infections. Fungal infections are caused by microscopic plants (fungi) that can live on the skin. They can live on the dead tissues of the hair, nails, and outer skin layers. Fungal infections include mold-like fungi (dermatophytes, causing tinea infections) and yeast-like fungi (such as Candida). Tinea infections include athlete's foot, jock itch, ringworm, and tinea capitis. Candida (yeast infections) include diaper rash, oral thrush, cutaneous candidiasis, and some cases of genital rashes.

Fungal nail infections are most often seen in adults. They usually follow fungal infection of the feet or hands. Fungal nail infections may be difficult to treat and may recur often. Toenails are affected more often than fingernails.

Individuals who frequent public swimming pools, gyms, or shower rooms and people who perspire a great deal commonly have tinea infections, because the fungi that cause them thrive in warm, moist areas. Susceptibility to fungal infection is increased by occlusive footwear, prolonged moist skin, and minor skin or nail injuries.

Fungal infections are contagious and can be spread from direct contact or contact with towels or shower and pool surfaces.