Tinea pedis is the most common dermatophytosis because foot sweating results in accumulation of moisture in the warm areas between the toes that allows fungi to grow. The infection may spread from person to person in communal showers and bathrooms or in other moist areas where infected people walk barefoot. People who wear tight shoes are also at risk. The infection is usually caused by Trichophyton.
(See also Overview of Fungal Skin Infections.)
The fungus can cause mild scaling with or without redness and itching. The scaling may involve a small area (particularly between the toes) or the entire sole of the foot. Sometimes scaling is severe, with breakdown and painful cracking (fissuring) of the skin. Fluid-filled blisters can also form. Over time, the skin on the soles may thicken. Because the fungus may cause the skin to crack, tinea pedis can lead to bacterial infections, especially in older people and in people with inadequate blood flow to the feet.
The diagnosis of tinea pedis is usually obvious to doctors based on symptoms and the appearance of the affected area.
If the diagnosis is not obvious, doctors do a skin scraping and examine it under a microscope.
The safest treatment of tinea pedis is using antifungal drugs that are applied directly to the affected area (topical). However, tinea pedis commonly recurs, and people often have to use antifungal drugs for a long time. Antifungal drugs taken by mouth (oral), such as itraconazole and terbinafine, are effective but may have side effects. To possibly reduce recurrences, topical and oral antifungal drugs may be used at the same time.
Reducing moisture on the feet and in footwear helps prevent recurrences. Wearing open-toe shoes or shoes that “breathe” and frequently changing socks are important, especially during warm weather. Spaces between toes should be thoroughly towel-dried after bathing. To help keep the feet dry, people may apply antifungal powders (such as miconazole), gentian violet, or aluminum chloride solution or soak their feet in Burow solution (aluminum subacetate). (See also table Some Antifungal Drugs Applied to the Skin (Topical Drugs).)