Athlete's Foot (Tinea Pedis)

Who's At Risk?

Anyone of any age may develop athlete’s foot, though it is most commonly seen in teen males, and it is rarely seen in children. People with diabetes or immunosuppressive disorders are prone to more infections in general, including athlete’s foot.

Signs & Symptoms

The most common locations for athlete’s foot include:

• Spaces (webs) between the toes, especially between the 4th and 5th toes and between the 3rd and 4th toes
• Soles of the feet
• Tops of the feet

Athlete’s foot may affect one or both feet. It can vary in appearance, depending on which part of the foot (or feet) is involved and which dermatophyte has caused the infection:

• On the top of the foot, athlete’s foot appears as a red scaly patch or patches, ranging in size from 1 to 5 cm. The border of the affected skin may be raised, with bumps, blisters, or scabs. Often, the central portion of the lesion is clear, leading to a ring-like shape and the descriptive (but inaccurate) name “ringworm.”
• Between the toes (the interdigital spaces), athlete’s foot may appear as inflamed, scaly, and soggy tissue. Splitting of the skin (fissures) may be present between or under the toes. This form of athlete’s foot tends to be quite itchy.
• On the sole of the foot (the plantar surface), athlete’s foot may appear as pink-to-red skin with scales ranging in size from a small area affected to widespread (diffuse).
• Another type of infection, called bullous tinea pedis, appears as painful and itchy blisters on the arch (instep) and/or the ball of the foot.
• The most severe form of the infection, called ulcerative tinea pedis, appears as painful blisters, pus-filled bumps (pustules), and shallow ulcers. These lesions are especially common between the toes but may involve the entire sole. Because of the numerous breaks in the skin, lesions commonly become infected with bacteria. Ulcerative tinea pedis occurs most frequently in people with diabetes and in others with weak immune systems.

Self-Care Guidelines

If you suspect that you have athlete’s foot, you might try one of the following over-the-counter antifungal creams or lotions:

• Terbinafine
• Clotrimazole
• Miconazole

Apply the antifungal cream between the toes and to the soles of both feet for at least 2 weeks after the areas are completely clear of lesions.

In addition, try to keep your feet dry, creating conditions where the dermatophyte cannot live and grow:

• Wash your feet daily and dry them carefully, even using a hair dryer (on low setting) if necessary.
• Use a separate towel for your feet, and do not share this towel with anyone else.
• Wear socks made of cotton or wool, and change them once or twice a day, or even more often if they become damp.
• Avoid shoes made of synthetic materials such as rubber or vinyl.
• Wear sandals as often as possible.
• Apply antifungal powder to your feet and inside your shoes every day.
• Wear protective footwear in locker rooms and public or community pools and showers.

Treatments

To confirm the diagnosis of athlete’s foot, your physician might scrape some surface skin material (scales) onto a glass slide and examine it under a microscope. This procedure, called a KOH (potassium hydroxide) preparation, allows the doctor to look for tell-tale signs of fungal infection.

Once the diagnosis of athlete’s foot has been confirmed, your physician will probably start treatment with an antifungal medication. Most infections can be treated with topical creams and lotions, including:

• Over-the-counter preparations such as terbinafine, clotrimazole, or miconazole
• Prescription-strength creams such as econazole, oxiconazole, ciclopirox, ketoconazole, sulconazole, naftifine, or butenafine

Other topical medications your physician may consider include:

• Compounds containing urea, lactic acid, or salicylic acid, to help dissolve the scale and allow the antifungal cream to penetrate better into the skin
• Solutions containing aluminum chloride, which reduces sweating of the foot
• Antibiotic creams to prevent or treat bacterial infections, if present

Rarely, more extensive infections or those not improving with topical antifungal medications may require 3–4 weeks of treatment with oral antifungal pills, including:

• Terbinafine
• Itraconazole
• Griseofulvin
• Fluconazole
• Ketoconazole

The infection should go away within 4–6 weeks after using effective treatment.

Visit Urgency

If the lesions do not improve after 2 weeks of applying over-the-counter antifungal creams or if they are exceptionally itchy or painful, see your doctor for an evaluation. If you have fluid- or pus-filled lesions and/or open sores on your feet, see a doctor as soon as possible.

Trusted Links

• Clinical Information and Differential Diagnosis of Tinea Pedis (Athlete's Foot, Ringworm of Foot or Feet)

References

Bolognia, Jean L., ed. Dermatology, pp.1174-1185. New York: Mosby, 2003.

Freedberg, Irwin M., ed. Fitzpatrick’s Dermatology in General Medicine. 6^th ed. pp.1251, 2000-2001, 2337, 2340-2041, 2446-2447. New York: McGraw-Hill, 2003.