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Jock itchBy Mayo Clinic staff
Original Article: http://www.mayoclinic.com/health/jock-itch/DS00490
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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 often occurs in people who are overweight, but anyone can get this condition.
Although often uncomfortable and bothersome, jock itch usually isn't serious, except possibly for people with weak immune systems. Keeping your groin area clean and dry and applying topical antifungal medications usually are sufficient to treat jock itch.
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The signs and symptoms of jock itch may include:
- Itching and redness in your groin, including your genitals, inner thighs and buttocks
- Possible itching in your anal area
- Burning sensation in affected areas
- Flaking, peeling or cracking skin in your groin
Jock itch can make wearing underwear or tight clothing uncomfortable. Walking or exercising may aggravate the rash and worsen your signs and symptoms.
When to see a doctor
See your doctor if you have a rash on your skin that doesn't improve within two weeks. You may need prescription medication. If excessive redness, swelling, drainage or fever occurs, see your doctor.
Jock itch is caused by fungi called dermatophytes. These microscopic organisms are normal inhabitants of your skin, and their growth stays in check as long as your skin is clean and dry. But on some areas of the body where skin is more likely to be moist and warm, such as the groin, the fungi grow and thrive, resulting in a fungal infection.
This infection is often caused by the same type of fungus that causes athlete's foot and, sometimes, ringworm of the scalp. In fact, the fungus that infects your groin area may be spread there from your own athlete's foot infection.
Jock itch can spread from person to person by shared use of contaminated towels or clothing or through direct contact during sexual intercourse with someone who has the infection.
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
Tests and diagnosis
Your doctor can determine if you have jock itch or another skin disorder, such as dermatitis or psoriasis.
Your doctor may take skin scrapings or samples from the infected area and view them under a microscope. This is called a potassium hydroxide (KOH) test. If a sample shows fungi, treatment may include an antifungal medication. If the test is negative, but your doctor still suspects that you have jock itch, a sample may be sent to a lab to determine whether it will grow fungi under the right conditions. This test is known as a culture. Your doctor may also order a culture if your condition doesn't respond to treatment.
Treatments and drugs
For a mild case of jock itch, your doctor may suggest first using an over-the-counter antifungal ointment, lotion, powder or spray. If you also have athlete's foot, treat it at the same time you are treating your jock itch to reduce the risk of recurrence.
People with weak immune systems, such as those with diabetes or HIV/AIDS, may find it more difficult to get rid of this infection.
Jock itch is treated with one of two types of antifungal medications, allylamines and azoles. The rash may clear up quickly with these treatments, but continue applying the medication twice a day for at least 10 days.
- Allylamines. These drugs, such as terbinafine (Lamisil AT), require shorter treatment time than do azoles.
- Azoles. These drugs, including miconazole and clotrimazole (Lotrimin AF), are less expensive than are allylamines.
If jock itch is severe or doesn't respond to over-the-counter medicine, you may need a prescription-strength topical or oral medication.
- Topical medications. These include econazole and oxiconazole (Oxistat).
Oral (systemic) medications. Your doctor may prescribe itraconazole (Sporanox), fluconazole (Diflucan) or terbinafine (Lamisil) Side effects from these medications include gastrointestinal upset, rash and abnormal liver function. Taking other medications, such as antacid therapies for ulcer disease or gastroesophageal reflux disease (GERD), may interfere with the absorption of these drugs. Oral medications for fungal infection may alter the effectiveness of warfarin, an anticoagulant drug that decreases the clotting ability of your blood.
Another oral medication, griseofulvin (Grifulvin V), is sometimes used to treat fungal skin infections. Although it's effective, it may take longer to clear up the infection. Potential side effects include headache, discomfort in the digestive tract, sensitivity to light, rashes or a drop in your white blood cell count. Griseofulvin may be used for people who are allergic to other antifungal medications, or for people who have other medical conditions that may be negatively affected by other medications, such as people with liver disease.
Reduce your risk of jock itch by taking these steps:
- Bathe daily. Shower or bathe daily and after exercising, participating in sports or sweating excessively. This helps keep the number of bacteria on your skin in check. Wash your hands often to avoid the spread of infection.
- 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. Also make sure shared exercise machines are cleaned between uses.
- Treat athlete's foot. Control any athlete's foot infection to prevent its spread to the groin.
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- Trevino J, et al. Tinea (dematophyte) infections. American Academy of Dermatology. http://www.aad.org/education/students/Tineainfect.htm. Accessed Sept. 27, 2010.
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