The Facts

Tinea cruris, commonly referred to as jock itch, is a fungal infection in the groin area. It affects mostly adult men. It's caused by a type of fungus called dermatophytes. It grows in a circle on your skin and often looks like a ring. Due to irritation, the skin becomes red.

Some people think the infection looks like there is a worm under the skin. Because of this, this infection is often referred to as "ringworm," although no worm is actually involved. The fungi are commonly found on the skin surface and nails and are usually quite harmless. Under certain conditions, however, they can multiply dramatically, causing irritation and surface tissue damage.

You don't have to be athletic to get jock itch. Infections caused by these organisms go by the medical name tinea. Tinea pedis is athlete's foot; tinea capitis is ringworm of the scalp. Jock itch is tinea cruris, from the Latin word for leg. They are all caused by dermatophytes – only the infected area differs.

Classic jock itch affects the inner thighs, groin, and lower buttocks, not the genitalia themselves. If the scrotum is inflamed, it's probably due to a different yeast condition called candidiasis, and a physician should be consulted.


Dermatophytes like to grow on skin that's moist and warm and thrive in areas where skin comes into contact with other skin, such as the groin or between the toes. Overweight men are more likely to develop jock itch if they sweat a lot or have folds of touching skin. Tight clothing and hot, humid weather are other risk factors.

Men who play sports and use a male athletic guard are particularly prone to tinea infection. Sweaty equipment left in a locker makes an ideal environment for tinea to grow. The fungi can live on towels, floors, carpets, and toilet seats. Sharing towels, combs, and shoes can easily transmit fungal infections.

Since the same dermatophytes can cause different types of tinea, it is not uncommon for someone with athlete's foot to get jock itch by towelling his feet before his groin.

Symptoms and Complications

Tinea is often painful or itchy, but not in every case. There are visual clues to help identify a fungal infection. These include:

  • inflammation of the groin, anal area, and upper thigh – not including the genitals themselves
  • slightly raised patch
  • sharp borders
  • expanding or spreading, with clearing in the centre
  • dry or scaly blisters (occasionally oozing or crusting)
  • abnormally dark or light skin
  • skin redness or inflammation

Fungal infections often spread out in a circle, leaving normal-looking skin in the middle. At the leading edge of the infection the skin is raised, red, and scaly.

Making the Diagnosis

Any number of conditions (e.g., eczema, lice, candidiasis, scabies, and seborrhea) can make the groin area itch, but a doctor can determine what is causing the problem. A doctor may scrape a small piece of irritated skin and examine it under a microscope. Sometimes, a doctor may send a skin sample to a laboratory to determine what is causing the skin irritation.

When a man sees his doctor about jock itch, he may be asked what sort of exercise he does, or what clothes he wears, or if he has any pets. Tinea can easily recur after treatment if the source of infection is not removed, so it's important to know where it came from.

Treatment and Prevention

Tinea cruris is considered a mild condition and is usually treated with medications that often do not require a prescription. It should easily clear up after 2 to 4 weeks with an antifungal cream, ointment, powder, or lotion applied to the affected area 1 or 2 times a day. The medication should be applied beyond the border of the affected area to ensure that the entire area is treated.

Antifungal creams and powders such as clotrimazole* or miconazole, available without prescription at the pharmacy, are effective against most dermatophytes. It's important to continue use after the infection has disappeared for as long as the instructions recommend. If athletes foot is also present it is important to treat it at the same time as well, otherwise the groin infection will likely recur.

If the inflammation or infections are widespread and difficult to heal despite the use of over-the-counter antifungal medication, see a doctor. The doctor may prescribe a different antifungal cream or possibly an antifungal medication taken by mouth to treat the infection.

Follow these tips to help to relieve and prevent jock itch:

  • Wear loose-fitting cotton clothing and underwear.
  • Change underwear often, especially after sweating.
  • Shower as soon as possible after exercising.
  • Wash exercise clothes after each use.
  • Don't sit around in a wet bathing suit.
  • Don't use another person's towel or clothes, or share your own personal items.
  • After showering, put socks on first. If underpants are put on first, foot fungus can rub off into the underwear, and cause jock itch.
  • Use nonmedicated powders in areas more likely to become infected to keep them free of moisture.
  • Take your pet to the vet if it has a rash or is missing patches of hair. This could be a possible sign of a tinea infection.

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