Jock itch is a fungal infection of the skin on the groin, upper inner thighs, or buttocks. It most commonly occurs in hot, humid conditions. Doctors often refer to jock itch as tinea cruris.

Jock itch is caused by common fungus organisms that grow best in warm, moist areas. Jock itch can affect women, but most commonly affects men, especially men who perspire heavily.

The fungus that causes jock itch most often results from:

• Wearing wet, damp, or unlaundered clothing (such as underwear or an athletic supporter)
• Sharing towels that are infected with jock itch fungus
• Infrequent showering, especially after exercising or perspiring heavily from work

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors for jock itch include:

• Hot, humid conditions
• Heavy perspiration
• Obesity
• Tight clothing
• Rewearing clothing, especially underwear or athletic supporters, before laundering
• Changing underwear infrequently
• Infrequent showering
• Sharing towels or clothing with other people
• Using public showers or locker rooms
• Immune system disorders

Jock itch causes a chafed, itchy, sometimes painful rash in the groin, upper inner thigh, or buttock. The rash is:

• Usually red, tan, or brown
• Usually defined clearly at the edges
• Often slightly scaly

Jock itch can usually be diagnosed based on the appearance and location of the rash. However, other skin problems may look similar to jock itch. If you are not certain of the diagnosis, contact your doctor.

The doctor will ask about your symptoms and medical history, and perform a physical exam. In some cases, your doctor may order a lab test of the infected skin area. Testing usually consists of a skin scraping that can be viewed under a microscope or cultured.

Over-the-counter antifungal creams can usually treat jock itch. Creams or lotions work better on jock itch than sprays. In severe or persistent cases, your doctor may prescribe stronger creams or oral medication. Use your prescription for the entire time that your doctor recommends. This will help prevent reoccurrence of the rash. If your rash does not resolve within a month of treatment, contact your doctor.

Antifungal creams for jock itch include:

• Miconazole
• Clotrimazole
• Econazole
• Oxiconazole (Oxistat)
• Ketoconazole
• Terbinafine (Lamisil)
• Tolnaftate
• Ciclopirox (Penlac)
• Haloprogin (Halotex)
• Naftifine (Naftin)
• Undecylenic acid

While all of these medications can effectively treat jock itch, terbinafine may lead to a more rapid cure than some of the others. It is also considerably more expensive than most of the medications in the above list. Tolnaftate and undecylenic acid may be less effective than some of the other medications listed, but as generics, they are generally among the least expensive treatments available. Creams are usually applied twice daily for 2-4 weeks. Follow the instructions given on the package or by your pharmacist or physician.

Do not use antifungal creams recommended specifically for athlete's foot . They may be too harsh for the groin. In some cases, over-the-counter antifungal creams may not work or effectively treat the rash. In these cases, your doctor can prescribe a stronger antifungal cream.

If your jock itch rash begins to ooze, call your doctor. This may be an indication that the rash may be secondarily infected with bacteria. If your doctor confirms that it is, you may be given an antibiotic.