Definition of Athlete's foot:

Athlete's foot is an infection of the feet caused by fungus. The medical term is tinea pedis. Athlete's foot may last for a short or long time and may come back after treatment.

Causes, incidence, and risk factors:

Athlete's foot occurs when a certain fungus grows on your skin in your feet. In addition to the toes, it may also occur on the heels, palms, and between the fingers.

Athlete's foot is the most common type of tinea fungal infections. The fungus thrives in warm, moist areas. Your risk for getting athlete's foot increases if you:

• Wear closed shoes, especially if they are plastic-lined
• Keep your feet wet for prolonged periods of time
• Sweat a lot
• Develop a minor skin or nail injury

Athlete's foot is contagious, and can be passed through direct contact, or contact with items such as shoes, stockings, and shower or pool surfaces.

Symptoms:

The most common symptom is cracked, flaking, peeling skin between the toes or side of the foot. Other symptoms can include:

• Red and itchy skin
• Burning or stinging pain
• Blisters that ooze or get crusty

If the fungus spreads to your nails, they can become discolored, thick, and even crumble.

Athlete's foot may occur at the same time as other fungal skin infections such as ringworm or jock itch.

See also: Fungal nail infection

Signs and tests:

Your health care provider can diagnose Athlete's foot simply by looking at your skin. If tests are needed, they may include:

• Skin culture
• Skin lesion biopsy
• Skin lesion KOH exam

Treatment:

Over-the-counter antifungal powders or creams can help control the infection. These generally contain miconazole, clotrimazole, or tolnaftate. Keep using the medicine for 1 - 2 weeks after the infection has cleared to prevent the infection from returning.

In addition:

• Keep your feet clean and dry, especially between your toes.
• Wash your feet thoroughly with soap and water and dry the area very carefully and completely. Try to do this at least twice a day.
• Wear clean, cotton socks and change your socks and shoes as often as necessary to keep your feet dry.

Athlete's foot almost always responds well to self-care, although it may come back.

If athlete's foot does not get better in 2-4 weeks with self-care, or frequently returns, see your health care provider. The health care provider may prescribe stronger antifungal medications, such as ketoconazole or terbinafine. Antibiotics may be necessary to treat bacterial infections that occur from scratching.

Expectations (prognosis):

Athlete's foot infections range from mild to severe and may last a short or long time. They may persist or recur, but they generally respond well to treatment. Long-term medication and preventive measures may be needed.

Complications:

• The condition returns
• Bacterial skin infections such as cellulitis
• Lymphangitis, lymphadenitis

Calling your health care provider:

Call your doctor right away if:

• Your foot is swollen and warm to the touch, especially if there are red streaks. These are signs of a possible bacterial infection. Other signs include pus, drainage, and fever.
• You have diabetes or a weakened immune system and develop athlete's foot.

Also call your doctor if athlete's foot symptoms do not go away within 2- 4 weeks of self-care treatments.

Prevention:

To prevent athlete's foot, follow these measures:

• Dry your feet thoroughly after bathing or swimming.
• Wear sandals or flip-flops at a public shower or pool.
• Change your socks often to keep your feet dry. This should be done at least once a day.
• Use antifungal or drying powders to prevent athlete's foot if you are susceptible to getting it, or you frequent areas where athlete's foot fungus is common (like public showers).
• Wear shoes that are well ventilated and, preferably, made of natural material such as leather. It may help to alternate shoes each day, so they can dry completely between wearings. Avoid plastic-lined shoes.