Fungal groin infection

What is tinea cruris?

Tinea cruris is a fungal skin infection of the groin. Some types of fungal germs (fungi) are commonly found on human skin.

They usually do no harm. However, if conditions are right they can 'invade' the skin, multiply and cause infection.

The conditions fungi like best are warm, moist and airless areas of skin, such as the groin, under the arms and under the breasts.

Tinea cruris is sometimes called jock itch because it is common in athletes. It can be difficult for athletes to treat jock itch because the groin tends to become warm and moist during their sports activities.

What does tinea cruris look like?

Fungal groin infection (tinea cruris)

By Robertgascoin (Own work), via Wikimedia Commons

Jock itch heat rash

Gerardolagunes, CC BY-SA 3.0, via Wikimedia Commons

Tinea cruris symptoms

Symptoms of tinea cruris include:

• The groin becomes itchy and a bit sore, mainly in the crease between the top of the leg and the genitals.

• In men the scrotum may also be itchy.

• Red, slightly scaly skin in the groin, usually with a definite edge or border. Both sides are commonly affected.

• The rash often spreads a short way down the inside of both thighs.

Sometimes the infection spreads to the skin on other parts of the body (or may have first started in another area, such as athlete's foot (tinea pedis)). Fungal infections do not usually go deeper than the skin into the body and are not usually serious.

Fungal groin infections are more common in men than women.

When to see a doctor about tinea cruris

You should see a GP if:

• The rash is painful or you develop a fever.

• The rash has not improved after a week of using a topical antifungal medicine as recommended by a pharmacist.

• The rash hasn't cleared up fully after three weeks of treatment.

• You have a weakened body defence (immune system), eg, if you are having chemotherapy, have diabetes, or have any other condition that weakens the immune system.

Tinea cruris diagnosis

The diagnosis can usually be made by the features of the rash. Occasionally, if there is doubt about the diagnosis, skin scrapings can be sent to the laboratory to identify features that would indicate a fungal infection. If there is any concern that the diagnosis may be more serious then you may be referred to a specialist (dermatologist) and may need a skin biopsy.

Tinea cruris treatment

Self-care

• Wear loose-fitting clothes made of cotton or material designed to keep moisture away from the skin.

• Good hygiene by washing affected skin areas daily.

• Dry thoroughly after washing, especially in the skin folds.

• Avoid scratching, which may spread the infection to other sites.

• Do not share towels, and wash them frequently, to reduce the risk of passing on the infection to someone else.

• Wash clothes and bed linen frequently to get rid of any fungal spores.

If a child is affected, it is not necessary to exclude them from school or nursery.

Topical antifungal creams

A topical antifungal cream can be used if there is mild, non-extensive disease. Options include terbinafine, clotrimazole, miconazole, or econazole cream.

Treatment with a topical antifungal cream may be repeated in the future if there is a good response to topical treatment and there are recurrent episodes of mild, non-extensive disease.

An antifungal powder can be used (eg, miconazole) but creams are recommended as being more effective.

Steroid cream

A mildly-potent topical corticosteroid can be used in addition to a topical antifungal cream if there is associated marked inflammation, eg, hydrocortisone 1% cream, applied once daily for a maximum of 7 days.

A topical corticosteroid preparation should not be used alone on skin lesions.

Oral antifungal treatment

For severe or extensive disease, adults can be prescribed oral antifungal treatment, such as terbinafine. Oral itraconazole or oral griseofulvin can be used if terbinafine cannot be used or causes any side effects.

A child with severe or extensive disease should be referred to a specialist (paediatric dermatologist).

You can read more about treatments for fungal infections in the separate leaflet called Antifungal Medicines.

Tinea cruris outcome

Tinea cruris usually clears up in 1 to 3 weeks with treatment, including antifungal creams.

However, for people who are particularly susceptible, such as athletes and those who sweat a lot, recurrences are common and the problem may become long term (chronic).

Preventing recurring tinea cruris

To prevent any recurring tinea cruris (fungal groin infection) you should continue with self-care as outlined under treatment above:

• Wash your groin daily; then dry thoroughly. Drying is perhaps the most important point. It is easy to put on underwear when your groin is not quite dry. The damp groin is then an ideal site for fungal germs (fungi) to multiply. (A hairdryer is useful if you have hairy groins.)

• Change underwear daily. Fungi may multiply in flakes of skin in unwashed underwear.

• Check for athlete's foot (tinea pedis) and treat it if you have it. Athlete's foot is a common fungal infection of the toes. In a typical case of athlete's foot, the skin between the toes is itchy and flaky - especially between the outer two toes. The fungi from athlete's foot may spread to the groin. The same creams are used to treat athlete's foot and tinea cruris.

• Do not share towels with people in communal changing rooms. Wash towels frequently.

• Keep your own towel when you have a fungal skin infection to reduce the chance of passing on the fungus to others.