Tinea pedis (tin EE uh PEE duss) is a very common fungal infection on the skin of the feet. It is usually called athlete’s foot. The fungus grows best in dark, moist places. This same fungus can cause infection in the groin (called tinea cruris or jock itch).
On the feet, the rash often appears between the toes or on the instep of the foot. It can look like clear bumps, small blisters, or as peeling, cracking, or scaling skin. Often this is very itchy and sometimes causes a burning feeling.
Fungal infections can also occur in the toenails (called onychomychosis). This usually appears with scaling, crumbling, thickening and color changes such as yellowing of the nails. This is also a very common infection, but these kinds of nail changes can be caused by other things such as psoriasis, aging, or injury.
Athlete’s foot and toenail infections are spread easily from person to person (it is contagious). It may be spread by sharing socks or shoes, by close contact, or walking barefoot on the same floor as someone who has the fungus.
Sweaty feet (or feet that are not dried thoroughly after being wet) and tight shoes and socks make it easy for the fungus to grow, increasing risk for an infection (Picture 1).
Diagnosis and Treatment
Often a doctor can diagnose fungal infections of the feet and nails through an exam. Sometimes a scraping may be taken from the blisters or scales and looked at under a microscope.
A piece of the skin or nail may also be sent to the lab for testing. Simple cases of tinea pedis are treated with topical (on the skin) creams. For more severe cases and for infection of the toenails, oral (taken by mouth) medicine is usually prescribed.
Toenail infections are particularly difficult to treat. It can take months of treatment to see improvement. Occasionally, both topical and oral treatment is needed. Toenails grow very slowly. It takes a long time to see a completely healthy nail grow through.
What to Do at Home to Help Prevent Infection
Wear cotton or synthetic running socks, which absorb sweat.
Change your socks if they become damp or sweaty.
Wash your feet daily.
Dust an antifungal powder on your feet and in your shoes.
Avoid sharing shoes, socks, washcloths and towels.
Avoid tight footwear.
Dry your feet thoroughly after sweating, swimming or bathing.
HH-I-383 10/15 Copyright 2015, Nationwide Children's Hospital