Jock itch: symptoms, treatment, causes and how to stop it coming back

The NHS says to speak to a pharmacist first if you think you have ringworm. They can look at the rash and recommend the best antifungal medicine, which might be tablets, cream, gel or spray depending on where the rash is. You may need to use an antifungal medicine every day for up to 4 weeks, and it is important to use it for the right amount of time even if the rash has gone away.

For terbinafine, the NHS says the cream, gel or spray is put on the infected area once or twice a day for 1 to 2 weeks, it usually starts to work within a week, and you should talk to your doctor if symptoms do not get better within 2 weeks. If you take terbinafine tablets, the NHS says you will usually take them for 2 to 4 weeks if you have jock itch.

NICE Clinical Knowledge Summaries says that for mild, non-extensive disease, treatment is a topical antifungal cream such as terbinafine or an imidazole. A short-term, mildly potent steroid cream such as hydrocortisone may be added if there is marked inflammation, and an oral antifungal such as terbinafine is considered first for severe or extensive disease in adults. Do not use a steroid cream on its own, as NICE CKS notes that inappropriate use of topical corticosteroids can lead to treatment failure.

The NHS says the main symptom of ringworm is a rash. It may look red or darker than the surrounding skin, depending on your skin tone, and may be scaly, dry, swollen or itchy. The colour may be less noticeable on brown and black skin. It is usually ring-shaped, but it may look different in some places.

NICE Clinical Knowledge Summaries describes scaly, itchy skin with single or multiple red or pink, flat or slightly raised ring-shaped patches that enlarge outwards, with an active red, scaly advancing edge and a clear central area. In the groin it may involve the creases and the upper inner thighs, and the typical scaly edge may be lost in moist skin folds.

Jock itch is the common name for a fungal infection of the groin. NICE CKS says fungal infections of the body and groin are also called tinea corporis and tinea cruris, and are superficial skin infections predominantly caused by dermatophytes such as Trichophyton rubrum.

The NHS terbinafine page describes jock itch (sometimes called dhobie itch) as an infection in the groin area. It is a form of ringworm, which the NHS says is not caused by worms.

Jock itch is caused by fungi. NICE CKS says risk factors for developing infection include hot, humid environments, wearing tight-fitting clothing, obesity and hyperhidrosis (excess sweating).

It also says fungal groin infection is usually caused by spread from infection of the hands, feet or nails, which is why managing any fungal nail, foot or hand infection helps reduce the risk of reinfection.

It can be. The NHS says ringworm is caused by a type of fungi and can be passed on through close contact with an infected person or animal, infected objects such as bedsheets, combs or towels, and, less commonly, infected soil.

The NHS lists these steps to stop ringworm spreading: start treatment as soon as possible, wash towels and bedsheets regularly, keep your skin clean, do not share towels, combs or bedsheets with someone who has ringworm, and do not scratch the rash because this could spread it to other parts of your body.

The NHS says to see a GP if ringworm has not improved after using antifungal medicine recommended by a pharmacist, or if you have a weakened immune system, for example from chemotherapy, steroids or diabetes. A pharmacist will tell you if they think you should see a GP.

NICE CKS says that if signs persist after topical antifungal treatment, a GP should look for reasons treatment has failed, such as not following the self-care advice or treatment regimen, reinfection from close contacts, or an infection made worse by steroid cream, arrange skin sampling for fungal microscopy and culture, and consider oral antifungal treatment. Referral to a dermatologist is considered if the diagnosis is uncertain, treatment is unsuccessful or infections keep recurring.

The NHS and NICE CKS advice points to the following steps.

• Finish the full course of antifungal treatment, even if the rash looks better.

• Treat any fungal infection of the feet or nails as well, because groin infection usually spreads from these sites (NICE CKS).

• Wash towels and bedsheets regularly and do not share them.

• Keep your skin clean, and avoid tight-fitting clothing and hot, humid conditions where you can (NICE CKS risk factors).

• Do not scratch the rash.

Most people never need a GP: a pharmacist can see the rash and sell or recommend the right antifungal. If it does not improve, a GP can take a skin sample and prescribe tablets, with referral to a dermatologist if it keeps coming back.

Private dermatology can be useful for recurrent or resistant rashes, but the first steps are the same: a correct diagnosis, the right antifungal used for the full course and treatment of any infection at other sites.