Athlete's foot (tinea pedis) is a common fungal infection that develops in the moist areas between the toes or on the soles of the feet. It causes itching, stinging and burning, and, if left untreated, can cause the skin to peel and crack, which, in turn, can lead to bacterial infection. Athlete's foot can also affect the toenails, palms and fingers. It is caused by a variety of fungi that belong to the group "dermatophyte," which also causes ringworm, diaper rash and jock itch (dhobi itch).
Athlete's foot fungus thrives in a warm, moist environment. Fairly contagious, it is often spread in public areas such as swimming pools and locker rooms. It can spread from the feet to the hands or other body parts through physical contact, or from contact with contaminated objects such as rugs, linens, clothes or towels.
Risk Factors for Athlete's Foot
Susceptibility to athlete's foot increases with age, and men are more likely to contract it than women. Others at increased risk for athlete's foot include those who:
- Wear tight shoes
- Sweat a great deal
- Walk barefoot in moist public areas
- Share towels or other personal items
- Have weakened immune systems
- Have minor skin or nail injuries
Having had athlete's foot in the past increases the chance of its reoccurring.
Symptoms of Athlete's Foot
Typically, the first symptom of athlete's foot is itching between the toes. Other symptoms, including red, itchy, stinging or burning skin, and oozing or crusty blisters, may develop in a short period of time. The skin may flake, crack or peel. If the fungal infection spreads to the nails, the nails may become discolored, and thicken or, possibly, decompose.
Diagnosis of Athlete's Foot
Usually, athlete's foot is diagnosed by simple physical examination. In cases in which laboratory confirmation is necessary, a skin culture is taken, or a test called a "KOH exam" is administered. During a KOH exam, a scraping of skin cells is deposited in potassium hydroxide (KOH), which destroys all but the fungal cells, making microscopic detection of the fungus much simpler.
Treatment of Athlete's Foot
Most athlete's foot cases, particularly those treated early, respond well (usually within 1 to 2 weeks) to over-the-counter remedies that include creams, lotions and sprays. During the treatment period, keeping feet clean and dry, especially between the toes, and avoiding contact with contaminated surfaces is essential.
In some cases, when athlete's foot does not respond to treatment with over-the-counter medications, prescription medication may be necessary. Usually taken orally, this medication can have serious side effects, so is prescribed only when necessary.
In order to avoid a recurrence of athlete's foot, patients are advised to air out their feet as much as possible; to wear clean, dry socks; to avoid wearing shoes made of plastic; to dust their feet frequently with antifungal powders; and to avoid areas that may be contaminated with athlete's foot fungus. If the patient has contracted a bacterial infection as a result of athlete's foot, topical or oral antibiotics may be prescribed.