Jock itch (tinea cruris)

jock itch

Jock itch (also known as tinea cruris or ringworm) is a common fungal infection of the groin, upper thighs or buttocks. It causes an itchy, red rash which appears as patches with a scaly red border.

Symptoms

Symptoms of jock itch include:

  • itchy skin in the groin area;
  • a rash that appears as clearly-defined red, scaly areas, often in a ring shape;
  • occasional blisters at the border of the rash;
  • flaky skin; and
  • skin discolouration.

The rash usually affects the area at the top of the thigh, the inner thighs, and sometimes the skin of the buttocks. The skin of the genitals is rarely affected.

Symptoms can be aggravated by:

  • exercise;
  • walking; and
  • wearing tight clothes or underwear.

Causes

Jock itch (tinea cruris) is caused by an infection with dermatophytes (skin-loving fungi). Tinea is common, and can affect other areas of the body, such as the feet – this is known as athlete’s foot (or tinea pedis). In fact, jock itch and athlete’s foot often occur together in the same person as the fungus can be spread from one area to the other.

Tinea also commonly affects the scalp and nails.

Is jock itch contagious?

You can catch tinea from another person, either via direct contact or from sharing items such as clothing or towels. It is also possible to catch tinea from pets such as dogs and cats.

Who gets jock itch?

Jock itch usually affects young men and teenage boys. Fungus thrives in warm, moist environments, so athletes and people who sweat a lot are at increased risk.

Other factors that can increase your susceptibility to developing fungal infections include:

  • having diabetes;
  • being overweight or obese (which can aggravate chafing and sweating in the groin area);
  • having other skin conditions (such as eczema);
  • having had previous fungal skin infections; and
  • having a weakened immune system (due to illness or medicines used to treat other conditions).

Test and diagnosis

Jock itch is a common condition that can often be diagnosed based on your symptoms and a physical examination.

However, because there are a number of causes of an itchy, red rash in the groin area, your doctor may recommend taking a skin scraping, or sample, to be sent to a laboratory to test for fungus.

Testing skin scrapings is usually recommended before starting oral medicines for tinea infection. Testing may also be recommended if your jock itch is not responding to treatment.

Jock itch treatment

Antifungal medicine that is applied directly (topical antifungal) to the groin rash is the usual treatment for jock itch.

Antifungals come in a variety of preparations, including:

  • cream;
  • gel;
  • solution;
  • powder; and
  • spray.

Topical antifungals are usually available from your pharmacist. The pharmacist will be able to advise you which product is best for you.

If you have jock itch and athlete’s foot, it’s important to treat both infected areas at the same time to prevent re-infection.

In some circumstances, such as tinea that is severe or not responding to topical treatment, oral antifungal medicine is needed to treat jock itch.

Examples of oral antifungals include:

  • terbinafine (brand names Lamisil, Tinasil);
  • fluconazole (brand names Diflucan, Dizole); and
  • griseofulvin (brand name Grisovin).

Side effects

Common side effects of oral antifungal medicines include:

  • nausea;
  • diarrhoea;
  • headache; and
  • indigestion.

Some oral antifungal medicines are not suitable for use in certain people. Your doctor will be able to advise you on the most appropriate treatment.

Self-help

The following self-help measures are also important when treating jock itch.

  • Wash and thoroughly dry the skin in your groin area daily.
  • Change your underwear daily (or more frequently if you sweat a lot).
  • Wear loose-fitting underwear and avoid clothing that irritates the area.

Prevention

There are several things you can do to prevent jock itch from recurring.

  • Wash your groin area daily and dry the skin thoroughly.
  • Wear loose-fitting underwear. Clothing that is too tight can cause rubbing and chafing, which puts you at higher risk of getting jock itch.
  • Wear cotton underwear and try to avoid synthetic clothing to reduce the chance of infection.
  • Frequently wash clothes, towels, bed linen and groin supports.
  • Change out of damp sports gear as soon as possible.
  • Avoid sharing items such as towels and clothing.
  • If you have athlete’s foot, make sure it is treated to prevent the spread of fungal infection to the groin area. When getting dressed, put your socks on before your underwear so that you don’t transfer the infection from your feet to your groin.

References

1. Infected skin: fungal infections (revised October 2015). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2015 Nov. http://online.tg.org.au/complete/ (accessed Feb 2016).
2. MayoClinic. Jock itch (updated 17 Aug 2013). http://www.mayoclinic.org/diseases-conditions/jock-itch/basics/definition/con-20021468 (accessed Feb 2016).
3. NHS Choices. Ringworm and other fungal infections (updated 5 Mar 2015). http://www.nhs.uk/Conditions/ringworm/Pages/Introduction.aspx (accessed Feb 2016).
4. DermNet NZ. Tinea cruris (updated 29 Dec 2013). http://www.dermnetnz.org/fungal/tinea-cruris.html (accessed Feb 2016).
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