What is ringworm?
Ringworm is the name given to a number of infections caused by a group of fungi called dermatophytes. The condition has nothing to do with worms but 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.
What types of ringworm are there?
There are several types of ringworm, the most common being;
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 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 can affect African-Caribbean children living in urban areas. You usually catch scalp ringworm from another person.
What are the 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 wouldn'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.
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.
What are the 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.
Factors that increase the risk of developing a fungal infection include;
- Being very old or young
- Having had a fungal skin infection before
- Having diabetes
- Being obese
- Having circulation problems
- Using shared facilities, such as showers and gyms
Having 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.
How is ringworm diagnosed?
Your doctor will ask about your symptoms and examine you. If they are unsure what is causing your infection or want to confirm that it is ringworm, they 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. If your doctor suspects a fungal infection, they may start your treatment before the test results are back.
How is ringworm treated?
Ringworm is treated in several different ways and will depend on the part of your body affected and how severe your infection is. Usually your doctor will be able to treat you, but if the infection is severe or keeps coming back, they may refer you to a dermatologist who specialises in identifying and treating skin conditions. Your doctor 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.
A doctor 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. You can also buy terbinafine cream and some imidazole creams at a pharmacy without a prescription. 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, you may be prescribed a steroid cream to calm the irritation, as well as an antifungal cream. Often these two treatments are combined in the same cream.
If your ringworm infection is severe or affecting large areas of your body, your doctor may recommend oral antifungal medicines. Oral medicines are also used for treating scalp ringworm because creams can't kill the fungus in the hair shaft. Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.
If you have scalp ringworm, your doctor may also recommend that you use an antifungal shampoo as well as taking an antifungal medicine.
Nail ringworm can often be left untreated but if the infected nails are causing you difficulty, for example walking is painful, or your doctor thinks you could develop further infections they may prescribe you a medicated nail lacquer which you may need to use for up to one year.
What can I do to help myself?
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.