Jock itch (tinea cruris) is a fungal infection that affects the skin of your genitals, inner thighs and buttocks. Jock itch causes an itchy, red, often ring-shaped rash in these warm, moist areas of your body.
Jock itch gets its name because it is common in people who sweat a lot, as do athletes. It also is more likely to occur in people who are overweight.
Although often uncomfortable and bothersome, jock itch usually isn't serious. Keeping your groin area clean and dry and applying topical antifungal medications usually are sufficient to treat jock itch.
Jock itch usually begins with a reddened area of skin that spreads out from the crease in the groin in a half-moon shape onto the upper thigh. The border of the rash may consist of a line of small, raised blisters. The rash often itches or burns, and the skin may be flaky or scaly.
When to see a doctor
See your doctor if you have a rash on your skin that doesn't improve within two weeks or if you treat it with over-the-counter medications and it returns within a few weeks. You may need prescription medication.
Jock itch is caused by a type of fungus that can be spread from person to person or from shared use of contaminated towels or clothing. Jock itch is often caused by the same fungus that results in athlete's foot. It's common for the infection to spread from the feet to the groin, as the fungus can travel on your hands or on a towel.
The organisms that cause jock itch thrive in damp, close environments. You're at greater risk of jock itch if you:
- Are a man
- Are a teen or young adult
- Wear tight underwear
- Are overweight
- Sweat heavily
- Have a weakened immune system
- Have diabetes
Reduce your risk of jock itch by taking these steps:
- Stay dry. Keep your groin area dry. Dry your genital area and inner thighs thoroughly with a clean towel after showering or exercising. Use powder around your groin area to prevent excess moisture.
- Wear clean clothes. Change your underwear at least once a day or more often if you sweat a lot. Wash workout clothes after each use.
- Find the correct fit. Make sure your clothes fit correctly, especially underwear, athletic supporters and sports uniforms. Avoid tightfitting clothes, which can rub and chafe your skin and make you more susceptible to jock itch. Try wearing boxer shorts rather than briefs.
- Don't share personal items. Don't let others use your clothing, towels or other personal items. Refrain from borrowing these items from others as well.
- Treat athlete's foot. Control any athlete's foot infection to prevent its spread to the groin. If you spend time in moist public areas, such as a gym shower, wearing sandals will help prevent athlete's foot.