Causes - Athlete's Foot

A group of mold-like fungi called dermatophytes causes athlete's foot. These organisms sprout tendril-like microscopic extensions that infect the superficial layer of the skin. In response to this fungal growth, the basal layer of the skin produces more skin cells than usual. As these cells push to the surface, the skin becomes thick and scaly. Most often, the more the fungi spread, the more scales your skin produces, causing the ring of advancing infection to form.

The organisms that cause athlete's foot thrive in damp, close environments created by thick, tight shoes that squeeze the toes together and create warm, moist areas between them. Damp socks and shoes and warm, humid conditions also favor the organisms' growth. Plastic shoes in particular provide a welcoming environment for fungal growth and infection.

Athlete's foot is contagious and can be spread in the following ways:

Human to human. Athlete's foot often spreads by direct, skin-to-skin contact with an infected person. Not everyone who carries the fungus develops signs and symptoms of athlete's foot.

Object to human. The fungus is carried on fragments of skin or other particles that contaminate floors, mats, rugs, bed linens, clothes, shoes and other surfaces. Although transmission can occur within a household, the infection is more commonly passed along in public areas â€” locker rooms, saunas, swimming pools, communal baths and showers.

Animal to human. Household pets can pass along fungal infections to humans.