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
- Wear tight underwear
- Are overweight
- Sweat heavily
- Have a weakened immune system
- Have other skin conditions
The organisms that cause jock itch thrive in damp, close environments. Warm, humid settings that promote heavy sweating — thus washing away fungus-killing oils, making the skin more permeable and more prone to infection — favor its spread.
You're at greater risk of jock itch if you:
- Are a man, although women can also get the condition
- Wear tight underwear or athletic supporters that aren't washed after each use
- Are obese
- Sweat heavily
- Have an impaired immune system
- Have atopic dermatitis, a chronic, inherited skin disease characterized by itchy, inflamed skin
In many cases, your doctor can diagnose jock itch simply by looking at the rash. If the diagnosis isn't clear-cut, your doctor may take skin scrapings or samples from the infected area and view them under a microscope. To rule out other conditions, your doctor might send a sample of the rash to a lab. This test is known as a culture.
For a mild case of jock itch, your doctor may suggest first using an over-the-counter antifungal ointment, lotion, powder or spray. The rash may clear up quickly with these treatments, but continue applying the medication twice a day for at least 10 days.
If you also have athlete's foot, treat it at the same time you are treating your jock itch. This will reduce the risk of recurrence. If jock itch is severe or doesn't respond to over-the-counter medicine, you may need prescription-strength creams or ointments — or even antifungal pills.
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.
- Be cool. Don't wear thick clothing for long periods of time in warm, humid weather.
- 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.