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.
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 as directed for one to two weeks.
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.
Preparing for an appointment
Your family doctor or a skin specialist (dermatologist) can diagnose jock itch. Because appointments can be brief and there's often a lot of ground to cover, it can help to be well-prepared. Here are some tips to help you get ready for your appointment and what to expect from your doctor.
What you can do
Your time with your doctor may be limited, so preparing a list of questions can help you make the most of your appointment. List your questions from most important to least important in case time runs out. For jock itch, some basic questions to ask your doctor include:
- What's the most likely cause of my symptoms?
- Are tests needed to confirm the diagnosis?
- What treatments are available?
- Is this condition temporary or long lasting?
- Is there a generic alternative to the medicine you're prescribing?
- What can I do to prevent the infection from spreading?
- What skin care routines do you recommend while the condition heals?
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
- When did you first notice your symptoms?
- What did the rash look like when it first started?
- Have you had this type of rash in the past?
- Is the rash painful or itchy?
- Have you used any medications on it already? If so, what?