Athlete’s foot is an infection of the foot caused by fungi called dermatophytes which invade the "dead" outer layers of the skin. It is also called tinea pedis.
Athlete's foot, or tinea pedis, is a common, generally harmless foot infection caused by fungi that thrive in warm, moist, and dark environments. The condition was fairly uncommon before human beings started wearing shoes.
This fungus requires a warm and moist environment. Wearing poorly ventilated shoes and socks that harbor perspiration provide an ideal breeding ground for the germs that quickly multiply to cause athlete's foot. Contact with surfaces (shower, swimming pool and locker-room floors) that harbor the organism also contributes to development of this problem. It may also be transmitted by wearing the shoes of someone who has athlete’s foot.
Typical symptoms include scaling and peeling in the toe webs (the area between the toes) generally without any accompanying pain, odor, or itching. The infection may also involve the soles of the feet where athlete's foot may present as redness, blistering, and scaling along the sides and soles of the feet, taking on what is termed a moccasin pattern.
Over time, this condition can lead to a secondary bacterial infection. It’s possible for the fungus to set off a reaction that results in tissue breakdown — soggy skin and eroded areas between the toes. In advanced cases, the toe webs become whitened, softened, and soggy; they may itch severely, and there may be a foul odor. As the condition worsens, painful cracking in the toe webs and some oozing may develop.
Athletes foot can sometimes be associated with onychomycosis, a fungal infection of the toenails. However, the usual case of athlete's foot is a more superficial infection than the more stubborn and deep seated nail infection.
Sometimes after an episode of athlete's foot, if particles enter the bloodstream, there may be an allergic reaction causing blisters on the fingers, toes or hands.
If you have diabetes or an illness that makes it harder for your body to fight off infections, athlete’s foot can become a very serious infection in itself or facilitate secondary infections with other serious organisms. You should see a doctor immediately if your feet develop severe redness or swelling, areas of pus, and/or severe pain.
It is important to rule out other causes of similar symptoms. For example, hot, tight shoes may make the feet sweaty in warm weather; the moisture and friction may cause softening and peeling of the skin on the soles.
Dyes, adhesive cements, and other substances inside the shoes may cause irritation, as may powders and nail polishes. Eczema, psoriasis, and scabies are other possible causes of similar symptoms.
The doctor may do a KOH (potassium hydroxide) preparation, which involves gently scraping the scaly skin onto a microscope slide, adding KOH, and looking under the microscope for signs of fungus.
Treatment for athlete's foot is usually simple, uncomplicated, and usually carried out at home. Topical antifungal preparations should be effective in treating dry and scaly areas. These include topical clotrimazole (Lotrimin) and miconazole (available over the counter) and terbinafine (Lamisil) cream.
Sometimes, prescription oral antifungal medication may be required if the condition is severe. Medications may include griseofulvin, itraconazole (Sporanox), or terbinafine.
Side effects from these oral medications include gastrointestinal upset, rash and abnormal liver function tests. Also, in May 2001, the Food and Drug Administration (FDA) issued warnings that oral Sporanox and oral Lamisil had been linked to rare cases of liver failure and death, and that oral Sporanox may weaken heart contractions and should be avoided by people with a history of heart failure.
To relieve symptoms at home if the toe webs are macerated (soggy), doctors often recommend soaking the feet for twenty minutes, two times a day in a solution of aluminum subacetate, or 30 percent aqueous aluminum chloride. Broad spectrum antifungal creams and solutions may also be useful.
Athlete's foot is stubborn and will return when the conditions are right, no matter what common sense precautions one may take. To delay or help prevent its onset, a number of procedures should be followed:
- Always dry the feet, paying particular attention to the toe webs.
- After drying, apply antifungal lotion and follow this with an antifungal foot powder. Zeasorb AF is good because it contains no cornstarch, a substance that can encourage fungal growth.
- Wear socks made of absorbent fibers, and change them frequently (at least daily).
- Wear waterproof sandals in public showers and pools.
- When the feet are going to perspire excessively for extended periods of time, wear socks made of high turbo acrylic fiber. This will wipe the moisture away from the feet and carry it to the sock's outer layer to evaporate.
- When the weather is hot and humid, go barefoot whenever possible.
- Avoid tight, poorly ventilated shoes. Sandals or perforated shoes are best.
- Be sure to air your shoes at night and, if possible, do not wear the same street shoes or athletic footwear every day.