Athlete's foot is the most common of the fungal infections called tinea infections. It is a very common condition of itchy, peeling skin on the feet. Because the fungi grow well in warm, damp areas, they flourish in and around swimming pools, showers, gym floors, and locker rooms. The medical term tinea pedis got its common name (athlete's foot) because the infection was common among athletes.
Athlete's foot is commonly found with other fungal skin infections, such as jock itch (tinea cruris) and ringworm (dermatophytosis). Anyone can get athlete's foot. In fact, it is so common that most people will have at least one episode in their lives. It is found equally within all races of people. Men are more likely to get the condition than are women. It is more likely to be a problem as one grows older, beginning at puberty. Few children under the age of 12 years get athlete's foot. Symptoms that look like athlete's foot in young children most probably are caused by some other skin condition.
In addition, one is more likely to contract athlete's foot if one sweats profusely, especially on the feet; wears closed shoes, especially with plastic linings; has a minor skin or nail injury; has feet that are wet for long periods of time, such as when swimming or wading in water; comes into frequent contact with other people's shoes or socks; or is frequently around wet surfaces such as swimming pools.
Athlete's foot is caused by a fungal infection that most often affects the fourth and fifth toe webs (spacing between the fourth and fifth toes). Trichophyton rubrum, T. mentagrophytes, and Epidermophyton floccosum, the fungi that cause athlete's foot, are unusual in that these micro-organisms live exclusively on dead body tissue (hair, the outer layer of skin, and nails). The fungus grows best in moist, damp, dark places with poor ventilation. The problem does not occur among people who usually go barefoot, unless they walk on damp, moist floors where the fungi reside.
Many people carry the fungus on their skin. However, it will only flourish to the point of causing athlete's foot if conditions are right. It is a contagious condition. Why some people develop the condition and others do not is not well understood by the medical community.
Sweaty feet, tight shoes, synthetic socks that do not absorb moisture well, a warm climate, and not drying the feet well after swimming or bathing all contribute to fungus overgrowth.
If it is not treated, athlete's foot can spread to the soles of the feet and toenails. Stubborn toenail infections may appear at the same time, with crumbling, scaling, and thickened nails, and nail loss. The infection can spread further if patients scratch and then touch themselves elsewhere (especially in the groin, where it is called jock itch, or under the arms). It is also possible to spread the infection to other parts of the body via contaminated bed sheets or clothing.
For the following serious problems—the foot is swollen, warm when touched, discharges pus, or reddish in color—seek the medical help of a doctor. If one is diabetic, do not wait—go to the doctor immediately.
Not all foot rashes are athlete's foot. That is why a physician should diagnose the condition before any remedies are used. Using nonprescription products on a rash that is not athlete's foot could make the rash worse.
A dermatologist, podiatrist, or other medical professional can diagnose the condition by physical examination and by examining a preparation of skin scrapings under a microscope. This test, called a skin lesion KOH preparation, treats a sample of tissue scraped from the infected area with heat and potassium (K) hydroxide (OH). This treatment dissolves certain substances in the tissue sample, making it possible to see the fungi under the microscope. A skin culture (where fungi taken from the skin are grown in the laboratory) or skin lesion biopsy (where fungi taken from the skin are analyzed under a microscope) may also be used.
Athlete's foot can be treated, but it can be tenacious and difficult to clear up completely. Make sure to wash the feet thoroughly with soap and water at least twice daily, with special attention to those areas between the toes. Dry them completely. Wear clean, cotton socks and change the socks and shoes as frequently as necessary to make sure the feet stay dry. Do not wear the same shoes two days in a row so they have a chance to dry out completely.
The foot problem may be resistant to medication and should not be ignored. Simple cases usually respond well to topical over-the-counter antifungal creams, sprays, or medicated powders—such as clotrimazole (Atopalm, Clotrimazole Antifungal and others), miconazole nitrate (Miconazole), sulconazole nitrate (Exelderm), or tolnaftate (Absorbine Jr. Antifungal, Aftate, Tinactin, and others). If the infection is resistant to topical treatment, the doctor may prescribe an oral antifungal drug, such as itraconazole (Sporanox), fluconazole (Diflucan), or terbinafine (Lamisil). These systemic drugs can have significant side effects, however, so they are only used for severe cases of athlete's foot that have been resistant to other types of treatments. Additionally, if the athlete's foot has led to a secondary bacterial infection, an oral antibiotic may be necessary. Feet can also be soaked in a solution of aluminum acetate (such as Burow's solution or Domeboro solution).
A footbath containing cinnamon has been shown to slow down the growth of certain molds and fungi, and is said to be very effective in clearing up athlete's foot. To make the bath:
Other herbal remedies used externally to treat athlete's foot include a foot soak or powder containing goldenseal (Hydrastis canadensis), tea tree oil (Melaleuca), or calendula (Calendula officinalis) cream to help heal cracked skin.
Athlete's foot usually responds well to treatment, but it is important to take all medication as directed by a dermatologist or other medical professional, even if the skin appears to be free of fungus to prevent reoccurence. The toenail infections that may accompany athlete's foot, however, are typically very difficult to treat effectively. Secondary bacterial skin infections, such as cellulitis, can also occur. Generally, infections caused by athlete's foot range from being mild to severe and can be acute or chronic.
For the most part, medications will solve the problem if they are taken consistently and regularly for as long as the doctor recommends. The physician may also prescribe preventive measures so it does not return. If the condition should re-appear, stronger prescription oral antifungal medications may be prescribed, such as ketoconazole (Feoris, Nizoral), terbinafine (Lamisil, Terbinex), itraconazole (Sporanox), and fluconazole (Diflucan). Secondary bacterial infections may necessitate antibiotic treatment.
Good personal hygiene and a few simple precautions can help prevent athlete's foot. To prevent the spread of athlete's foot:
See also Blisters ; Exercise ; Swimming .
Anderson, Steven J., and Sally S. Harris, eds. Care of the Young Athlete. Elk Grove Village: American Academy of Pediatrics, 2010.
Bytomski, Jeffrey R., and Claude T. Moorman III, eds. Oxford American Handbook of Sports Medicine. Oxford: Oxford University Press, 2010.
Moorman III, Claude T., and Donald T. Kirkendall, eds. Praeger Handbook of Sports Medicine and Athlete Health. Santa Barbara: Praeger, 2011.
Werd, Matthew B., and E. Leslie Knight, eds. Athletic Footwear and Orthoses in Sports Medicine. New York: Springer, 2010.
Williams, Hywel C., et al. Evidence-based Dermatology, 3rd ed. Oxford: Blackwell/BMJ Books, 2014.
“Athlete's Foot.” Medline Plus. April 4, 2016. http://www.nlm.nih.gov/medlineplus/athletesfoot.html (accessed January 25, 2017).
“Athlete's Foot.” PubMed Health. June 10, 2009. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001878 (accessed June 27, 2011).
Cole, Gary. “Athlete's Foot.” MedicineNet.com . April 29, 2016. http://www.medicinenet.com/athletes_foot/article.htm (accessed January 25, 2017).
Gupta, Rupal Christine. “Athlete's Foot.” KidsHealth. July 2014. http://kidshealth.org/en/kids/athletes-foot.html (accessed January 25, 2017).
American Academy of Dermatology, PO Box 4014, Schaumburg, IL, 60168, (847) 240-1280, (888) 462-3376, Fax: (847) 240-1859, http://www.aad.org .
American Podiatric Medical Association, 9312 Old Georgetown Rd., Bethesda, MD, 20814-1621, (301) 581-9200, http://www.apma.org .
National Institute of Allergy and Infectious Diseases, 5601 Fishers Ln., MSC 9806, Bethesda, MD, 20892, (301) 496-5717, (866) 284-4107, Fax: (301) 402-3573, http://www.niaid.nih.gov .
Carol A. Turkington
Revised by William A. Atkins, BB, BS, MBA