Jock itch is a tinea infection of the groin area including the upper medial thighs, perineum, perianal region, and buttocks. It usually does not affect the scrotum or penis, nor does it often spread beyond the groin area. It is also called tinea cruris, the word cruris coming from the Latin word for leg.
The name jock itch comes from its association with the male athletic supporter (jockstrap), which not only can produce friction and moisture, two predisposing factors for a fungal infection but which often go unwashed for long periods and therefore can harbor fungal organisms. However, wearing a supporter is not necessary in order to be affected by jock itch, a predominantly male condition.
A frequent problem for male athletes, being unusual in females, tinea cruris is most commonly caused by Trichophyton rubrum,T. mentagrophytes, or Epidermophyton floccosum.
The infection causes very itchy, large, round, scaly plaques of a red to to yellowish-brown color. The plaques have a sharply defined border with pustules and papules at their edges. They tend to be bilateral but asymmetric. The infection usually starts closer to the genital area and spreads outwards towards the proximal inner thighs.
The primary causes are poor hygiene, inadequate ventilation of the groin area coupled with frequent sweating, friction, and being overweight. Those with large thighs that rub together can be at risk for jock itch, whether the large thighs are from being overweight or because the thighs are heavily muscled. Over-use of corticosteroids can also be a predisposing factor. Some people are more prone to jock itch than others and may be often reinfected.
Prevention of Jock Itch
- Proper hygiene
- Only wear an athletic supporter if absolutely necessary.
- Do not share towels or clothes with other athletes. If an athletic supporter must be used, wash it regularly.
- Always wear CLEAN athletic clothing. Do not keep used clothing in your gym locker and wear it more than once before washing.
- Avoid rough, textured, and synthetic fabrics. Loose cotton is best so that perspiration can better evaporate and the skin can “breathe.”
- Shower and change clothing as soon as possible after play, especially if there has been heavy perspiring. Don clean, dry, and loose clothing.
- Do not wear tight-fitting synthetic jockey shorts, especially those made of synthetic materials.
- For the overweight, heavily muscled, or those prone to jock itch, apply talcum powder to the groin area to help reduce wetness and chafing. Use a non-medicated powder, for preventative purposes. Medicated powders are for active infections. Do not use corn starch, as corn starch can encourage fungus growth. Talcum powder has been suggested to be an inhalation hazard and to be a risk for women (ovarian cancer) using it in the genital area, but evidence is not conclusive.
- When at home, or when possible, wear loose fitting, non-chaffing shorts to allow the groin area plenty of air
Treatment of Jock Itch (Tinea Curis)
Powders are generally used on affected areas to keep the skin dry. There are two common powders that should be avoided. Baby powder for jock itch should be avoided because these products are generally perfumed, which can irritate infected skin. Corn starch will absorb moisture, but the starch can be converted to sugars which will act as a growth medium for the fungus, making the infection worse.
Instead, to treat jock itch, follow all the preventative steps above, but use a non-perfumed talcum powder or a medicated powder such as Zeasorb-AF can be used instead of a non-medicated talcum.
Gently wash the area with soap and water, making sure to rinse off the soap thoroughly, as soap can further irritate the infection. Do not over-scrub. Dry the area thoroughly and keep it open to the air for as long as possible, whenever possible. Otherwise, apply a powder after bathing. Mild cases of jock itch may respond to this simple “wash, air out, and powder” treatment, but a topical antifungal such as clotrimazole (Lotrimin), available over-the-counter, is often required. Apply the cream in a thin coating twice daily and continue use for three to five days after the condition clears up, to prevent reinfection.
It is also a good idea to continue to apply a powder for several weeks after stopping the medication. As mentioned above, do not use a corn starch based powder.
If your jock itch does not respond to topical medication within three to five days, see a doctor. The doctor may need to take a small sample of the infected skin in order to pinpoint the fungus that is causing the infection so that the proper anti-fungal can be prescribed, although the appearance of the lesions should be enough for a diagnosis of tinea cruris. It is sometimes difficult to differentiate jock itch from dermal yeast infections. A systemic anti-fungal such as ketoconazole (Nizoral), or griseofulvin (Fulvicin-U/F, Grifulvi V) might be prescribed.