Ringworm

Published by Bupa's Health Information Team, May 2011.

This factsheet is for people who have ringworm, or who would like more information about it.

Ringworm is a common fungal skin infection that causes red, itchy patches to appear on the skin. It is treated with medicines that kill fungus (fungicides).

About ringworm

Ringworm is the name given to a number of infections caused by a group of fungi called dermatophytes. Despite its name, the condition has nothing to do with worms. It gets its name from the ring-like rash caused by the infection. The fungi can infect skin, nails or hair. Ringworm is infectious and can spread between people. You may also catch ringworm from an infected animal, but this is less common.

Types of ringworm

There are several types of ringworm. The most common are listed below.

• Ringworm of the body (Tinea corporis). This affects exposed areas of your body, like your abdomen (tummy) or legs and arms. You may catch this infection from domestic animals.
• Ringworm of the groin (Tinea cruris). This is more common in men than women and is known as 'jock itch' because it often affects athletes. If you have groin ringworm you may also have a ringworm infection of the foot (athlete's foot).
• Ringworm of the foot (Tinea pedis). This is commonly known as athlete's foot.
• Ringworm of the nail (Tinea unguium). This affects toenails more often than finger nails.
• Ringworm of the scalp (Tinea capitis). This is far more common in children than adults, and particularly affects African-Caribbean children living in urban areas. You usually catch scalp ringworm from another person.

                                                       Ringworm of the body

                                                      Ringworm of the nail

Symptoms of ringworm

Most ringworm infections cause an itchy rash that is red or scaly but symptoms vary depending on which part of your body is infected.

• Body ringworm causes red patches that have scaly edges and grow from the centre. The middle of your rash may clear up over time, leaving a red ring or series of red rings. Some people get blisters.
• Groin ringworm causes a red or red-brown rash on your thighs, groin and surrounding area. Your rash will have an obvious edge, and doesn't usually affect the penis and scrotum in men. At the edge of your rash you may see pustules or papules (solid rounded bumps).
• Athlete's foot causes the skin between your toes to turn white and crack. See Related topics for further information.
• Nail ringworm may cause your nails to change colour, turning them yellow or white. Your nail may thicken, become flaky and crumble away easily. The skin surrounding the nail may also thicken or become scaly.
• Scalp ringworm causes scaly patches of skin on the scalp. Your scalp can become inflamed and your hair may fall out. Sometimes, scalp ringworm can be more severe, causing a painful, oozing swelling called a kerion. This can cause a fever or make the glands behind your ears and in your neck swell up. It may lead to scarring and permanent hair loss.

Some people infected by ringworm don't develop symptoms, and unknowingly become carriers of the infection, spreading it to others. This is particularly common with scalp ringworm and ringworm of the foot.

If you have any of these symptoms, see your GP.

Causes of ringworm

Ringworm is infectious so you may catch it from direct contact with another person. You can also catch ringworm from an infected animal, and in rare cases, from fungal spores in soil. Dermatophyte spores can survive for a long time in soil, or on combs, bed sheets and furniture before spreading to other people.

There are a number of things that can increase your risk of developing a fungal infection like ringworm. You're more at risk from fungal infections if you:

• are very old or young
• have had a fungal skin infection before
• have diabetes
• are obese
• have certain circulation problems
• use shared facilities, such as showers and gyms
• have a weakened immune system, for example if you have HIV/AIDS, or if you're taking medicines that suppress the immune system

Moist skin encourages the growth of fungi, so you are more likely to develop a fungal infection if you haven't dried your skin properly after washing or sweating. Infections can develop when skin is unable to 'breathe' and is covered by a material that doesn't allow sweat to evaporate.

Diagnosis of ringworm

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history. If your GP isn't sure what is causing your infection or wants to confirm that it is ringworm, he or she may take a sample of the affected area to be analysed in a laboratory. This can help determine if you have ringworm, and the right type of treatment for you.

For a scalp infection your GP will collect scales and hair from the affected area. If you have an infection on your body, he or she will scrape some skin off the edge of the infected area using a scalpel or glass slide. If you have a nail infection, your GP may ask you to cut off a section of your nail.

Your GP may also take a sample from you if your infection is severe, or if it is not getting better with treatment.

If your GP suspects a fungal infection, he or she may start your treatment before your test results are back.

Treatment of ringworm

Ringworm is treated in several different ways. Your treatment will depend on the part of your body affected and how severe your infection is. Usually your GP will be able to treat you, but if the infection is severe or keeps coming back, he or she may refer you to a dermatologist (a doctor who specialises in identifying and treating skin conditions). Your GP is more likely to refer you to a dermatologist if you have a weakened immune system, for example if you have HIV/AIDS, or if you are taking medicines that suppress the immune system.

If you have scalp ringworm and your GP suspects that you have a kerion, he or she will refer you to a dermatologist.

Self-help

There are a number of things you can do yourself to help get rid of your ringworm and stop it spreading to other people.

• Wash the affected area daily.
• Wear loose and breathable clothing.
• Wear well fitting shoes made of a breathable fabric.
• Try not to expose your hands or feet to warm, damp conditions for long periods of time.
• Keep your nails short.
• Don't scratch any areas of your body infected with ringworm, as this can spread the infection.
• Wash your towels, bed linen and clothes frequently.
• Don't share towels, combs, hats or hairbrushes.
• Disinfect any hats, scissors, combs and hairbrushes that may be contaminated with the fungus.

If you think your pet is a source of ringworm infection, take it to the vet for a check-up. If your pet is found to be infected, get it treated.

Medicines

Creams

Your GP will usually prescribe an antifungal cream to treat mild ringworm of the body. Examples of these include imidazole creams or terbinafine cream. The creams need to be used for one to four weeks to clear up the infection, and for up to two weeks longer to stop it from coming back. If you're pregnant or breastfeeding, terbinafine isn't recommended so your GP may prescribe you clotrimazole or miconazole.

You can also buy terbinafine cream and some imidazole creams at a pharmacy without a prescription from your GP. Always read the patient information leaflet that comes with your medicine and if you have any questions ask your pharmacist for advice.

If your infection is very inflamed, your GP may prescribe you a steroid cream to calm the irritation, as well as an antifungal cream. Often these two treatments are combined in the same cream, for example Daktacort.

Oral antifungal medicine

If your ringworm infection is severe or affecting large areas of your body, your GP may prescribe you oral antifungal medicines. Oral medicines are also used for treating scalp ringworm because creams can't kill the fungus in the hair shaft. Examples of medicines you may be prescribed are terbinafine or griseofulvin. Griseofulvin can have unwanted side-effects on the reproductive systems, so men and women of childbearing age should be aware of this if using the medicine. Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.

Antifungal shampoos

If you have scalp ringworm, your GP may also recommend that you use an antifungal shampoo as well as taking an antifungal medicine. Examples of antifungal shampoos include ketoconazole and selenium sulphide.

Medicated nail lacquer

Nail ringworm can be left untreated. But if the infected nails are causing you difficulty, for example walking is painful, or your GP thinks you could develop further infections, he or she will prescribe you a medicated nail lacquer, such as amorolfine, or oral antifungal drugs. You may need to use nail lacquers for up to one year.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.