Jock itch is a type of fungal infection that affects the groin area, inner thighs, and buttocks.
It's also known as tinea cruris or ringworm of the groin (tinea is the medical term for ringworm).
The infection causes scaly, itchy, red or pink spots in the groin area, typically around the creases of the upper thigh.
It may spread to the anus and cause itching and discomfort in that area, but it typically doesn't affect the scrotum or penis.
The rash is often ring-shaped — redder on the outside with normal, clear skin in the center — and may blister and ooze.
It can sometimes cause abnormally dark or light skin, which may remain after the infection clears up.
What Causes Jock Itch?
Like other forms of ringworm, jock itch is caused by fungi known as dermatophytes.
There are more than 40 species of fungi that can cause ringworm, according to the U.S. Centers for Disease Control and Prevention (CDC).
Most cases of jock itch are caused by the dermatophytes Epidermophyton floccosum, Trichophyton mentagrophytes, and T. rubrum, according to a 2008 article in the journal Mycoses.
The fungi thrive in moist, warm areas. Although jock itch can affect both men and women, it's more common in adult men and teenage boys because of the moisture that develops between the scrotum and inner thigh.
People who are obese are also at an increased risk for jock itch because of their moisture-trapping skinfolds.
Additionally, wearing wet or tight clothing for a long time can allow fungi to spread and cause jock itch.
Is Jock Itch Contagious?
Jock itch is contagious, or easily spread.
You can get jock itch through direct skin-to-skin contact with someone who has the infection. You can also get it by wearing the unwashed clothes, or using the unwashed towel, of someone who has jock itch.
It's possible to spread a different ringworm infection — particularly tinea unguium (ringworm of the fingernails or toenails) or tinea pedis (athlete's foot) — to your groin.
For instance, you can get jock itch if you have athlete's foot and your feet touch the crotch area or waistband of your underwear while you're getting dressed.
Jock Itch Treatment
Jock itch and other forms of ringworm are highly treatable using over-the-counter (OTC) antifungal creams, lotions, or powders applied to the skin for 2 to 4 weeks.
These treatments include:
- Zeasorb, Daktarin, or Lotrimin (miconazole)
- Naftin (naftifine)
- Canesten AF cream (clotrimazole)
- Nizoral, Xolegel, or Extina (ketoconazole)
- Oxistat (oxiconazole)
If your infection is widespread or difficult-to-treat — or if it causes inflammation — prescription-strength antifungal tablets are also available.
These prescription-strength treatments include Sporanox or Onmel (itraconazole) and Lamisil or Terbinex (terbinafine).
Jock itch is often less severe than athlete's foot and other ringworm infections, but it may last for a long time, according to the National Institutes of Health.
Jock Itch Prevention
The following precautions can help reduce your risk of getting jock itch:
- Keep your groin, buttocks, and inner thighs dry and clean — such as by using powder when it's warm out, and drying thoroughly with a clean towel after showering or getting wet
- Avoid tight-fitting clothing, especially underwear and athletic supporters (jock straps)
- Don't reuse athletic clothing — particularly athletic supporters — without washing it first
- Don't share towels, clothing, or other personal items with other people without washing them first
- Treat other ringworm infections promptly
Last Updated: 8/23/2016