What causes athlete's foot?

Several types of fungi called dermatophytes are to blame for athlete's foot. These fungi grow on and infect the skin, causing the skin to produce extra cells. As the skin becomes thicker, it begins to develop the scaly appearance associated with athlete's foot. Development can begin through direct contact with the fungi, whether through another person or an object or surface that has been in contact with an infected person.

Athlete's foot (tinea pedis) is a fungal infection of the skin of the foot. Most athlete's foot is caused by one of two types of fungus.

• Trichophyton mentagrophytes often causes toe web or vesicular (blisterlike) infections. The infection appears suddenly, is severe and is easily treated.
• Trichophyton rubrum often causes moccasin-type infections. This condition lasts for a long time (chronic) and is difficult to treat.

You get athlete’s foot when you come in contact with the fungus and it begins to grow on your skin. Fungi commonly grow on or in the top layer of human skin and may or may not cause infections. Fungi grow best in warm, moist areas, such as the area between the toes.

Athlete's foot is easily spread (contagious). You can get it by touching the affected area of a person who has it. More commonly, you pick up the fungi from damp, contaminated surfaces, such as the floors in public showers or locker rooms.

Although athlete's foot is contagious, some people are more likely to get it (susceptible) than others. Susceptibility may increase with age. Experts don't know why some people are more likely to get it. After you have had athlete's foot, you are more likely to get it again.

If you come in contact with the fungi that cause athlete's foot, you can spread the fungi to others, whether you get the infection or not.

You don't have to be an athlete to develop athlete's foot, or tinea pedis, one of the most common types of fungal infection, affecting one in five adults. The condition, which affects men more often than women, is known as athlete's foot because walking around barefoot in a locker room is a good way to become infected. But you can also come in contact with the fungus in store dressing rooms, swimming pool changing areas, or any place that combines dampness and a lot of foot traffic. You can also be infected by improperly cleaned instruments used in a pedicure either at a commercial salon or at home. Whatever the source, fungi thrive in dark, damp environments -- for example, a sweaty foot in a shoe.