Athlete's foot, tinea pedis
Athlete's foot, tinea pedis

Tinea pedis

Definition:
Tinea pedis is an infection of the feet with mold-like fungi called dermatophytes.

Alternative Names:
Athlete's foot; Fungal infection - feet; Tinea of the foot; Infection - fungal - feet; Ringworm - foot

Causes, incidence, and risk factors:
The body normally hosts a variety of microorganisms, including bacteria, mold-like fungi (dermatophytes), and yeast-like fungi (such as Candida). Some of these are useful to the body. Others may, under proper conditions, multiply rapidly and cause infections.

Athlete's foot is an extremely common skin disorder. It occurs most frequently during and after adolescence and is fairly rare before. Athlete's foot is the most common and most persistent of the fungal (tinea) infections. It may occur in association with other fungal skin infections such as ringworm or jock itch. The dermatophytes that cause athlete's foot and similar infections, called tinea infections, live on the dead tissues of the hair, nails, and outer skin layers.

The fungi that cause tinea thrive in warm, moist areas. Susceptibility to tinea infection is increased by poor hygiene, occlusive (closed-up, such as tennis shoes) footwear, prolonged moist skin, and minor skin or nail injuries.

Tinea infections are contagious, and can be passed through direct contact, or contact with items such as shoes, stockings, and shower or pool surfaces. They also can be transmitted from contact with pets that carry the fungus. Athlete's foot may be brief or long-term and may recur after treatment.
Symptoms:
  • Itching, burning, stinging of the skin in the affected area
  • Rash on the feet (or hands)
Signs and tests:
The diagnosis is based primarily on the appearance of the skin.
  • Skin culture (fungi from flecks of skin are allowed to grow on special material)
  • Skin lesion biopsy (examination may show dermatophyte)
  • Skin lesion KOH exam.(skin scrapings in KOH show dermatophyte)
Treatment:
Athlete's foot usually responds to self-care:
Keep the skin clean and dry. Wash thoroughly with soap and water and dry the area carefully and completely. Blow-drying the feet with a hair dryer removes excess water from the outer layers of skin and is more effective than drying with a towel. Wear clean socks and change socks and shoes as often as necessary to keep the feet dry. Topical over-the-counter antifungal powders or creams, such as those that contain miconazole or clotrimazole, may be used to control the infection.

Severe or chronic infection may require further treatment by the health care provider. Oral antifungal medications may be given. Other topical antifungal medications, such as ketoconazole or terbinafine, may be needed. Antibiotics may be needed to treat secondary bacterial infections.

Wet dressings or medicated soaks are used to clean raw, wet or weeping lesions. Dry, scaly lesions may respond to topical creams or lotions.
Expectations (prognosis):
Athlete's foot infections range from mild to severe. They may persist or recur, but they generally respond to treatment. Long-term medication and preventive measures may be needed.
Complications:
Calling your health care provider:
Call for an appointment with your health care provider if athlete's foot symptoms do not respond to self-care measures.
Prevention:
Good personal hygiene helps prevent and treat athlete's foot. Antifungal or drying powders may be used as a preventive measure if a person is susceptible to athlete's foot, or if exposed frequently to areas where athlete's foot fungus is suspected (public showers, etc.).

Wearing sandals at a public shower or pool may help prevent athlete's foot, but these measures have not been shown to be of definite benefit. Drying the feet thoroughly after bathing or swimming has been shown to be the best means to prevent the disorder.

Wool socks allow moisture to be drawn away from the feet. Change the socks as frequently as needed to keep feet dry and, at a minimum, on a daily basis. Shoes should be well ventilated and preferably of natural material such as leather. It may be helpful to alternate shoes daily, so each pair can dry completely between wearings.

Review Date: 8/6/2001
Reviewed By: Michael Lehrer, M.D., Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network.
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