Images of Tinea Pedis (Athlete's Foot, Ringworm of Foot or Feet)
Tinea pedis is the medical term for athlete's foot, a very common fungal infection of the skin of the foot. Tinea infections, in general, are often called ringworm, though there is no worm involved in the infection; the name comes from the fungus that infects the skin, causing ring-shaped lesions to grow. Athlete's foot is harmless but very bothersome; it is usually quite itchy, and the affected skin may also burn and peel. The space between the toes is commonly affected and becomes red and often peels and itches; when the bottom of the foot is affected it may be less itchy but may form a tough, leathery skin.
Athlete's foot is named because it is acquired from contact with dark, moist places common to athletes, such as sneakers and locker room floors. Athlete's foot is contagious. The best way to avoid getting athlete's foot is to keep the feet dry at all times and to avoid the surfaces that the fungus lives on. The fungus can also be acquired from contaminated soil or animals.
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 and 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
- 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.
If you suspect that you have athlete's foot, you might try one of the following over-the-counter antifungal creams or lotions:
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.
When to Seek Medical Care
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.
Treatments Your Physician May Prescribe
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
- 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
Bolognia, Jean L., ed. Dermatology, pp.1174-1185. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.1251, 2000-2001, 2337, 2340-2041, 2446-2447. New York: McGraw-Hill, 2003.