Jock itch, a type of ringworm — which is not actually a worm, but a fungus — is a fungal infection that commonly affects athletes and other people prone to sweating.
Jock itch (medically called tinea cruris) typically affects the skin around the genitals, groin, inner thighs, and buttocks, areas with high amounts of sweating and chafing. The warm, moist environment in these spots makes them susceptible to the growth and development of the fungus, which appears as an itchy, scaly red rash, usually in a circular shape, which may become painful. It’s an especially hospitable place for the fungus to grow among people who spend a lot of time sweating: athletes, as you might guess from the name, as well as those who simply get a lot of physical activity or who are overweight.
Although it’s uncomfortable and unsightly, jock itch generally isn’t serious and in most cases can be easily treated at home. The first, and most important, step for both treatment and prevention is to keep the area as dry and clean as possible: don’t spend more time than is necessary in your sweaty clothes — shower immediately following your workout, then change into clean, dry clothing. Avoid re-wearing clothes and choose clean ones in light, breathable fabrics such as cotton instead of spandex or other synthetics. Wash your clothing (including socks and underwear) as well as your towels regularly, and wear shower shoes when using a public shower or sauna.
Your doctor will likely recommend an over-the-counter antifungal ointment or powder to start with. After thoroughly washing and drying the infected area, apply the cream liberally, making sure to spread it past the borders of the rash; keep using it as long as the directions state, which may be longer than it takes for the rash to clear up. Ingredients to look for include terbinafine, miconazole, and clotrimazole.
Some people may suffer from jock itch and athlete’s foot (another type of fungal infection) at the same time; in these cases, they should keep socks on while changing underwear or pants, in order to avoid infecting or re-infecting the groin with the infection on the feet.
If your rash doesn’t respond to these treatments within two weeks, see your doctor — they may prescribe a stronger topical treatment or antifungal pills.