Skin problems health centre

Ringworm: Symptoms, diagnosis and treatment

What is ringworm?

Worms don't cause ringworm. Rather, this superficial skin infection, also known as tinea, is caused by fungi called dermatophytes. Fungi are microscopic organisms that can live off the dead tissues of your skin, hair, and nails, much like a mushroom can grow on the bark of a tree.

Ringworm is characterised by a red ring of small blisters or a red ring of scaly skin that grows outward as the infection spreads. Though children are especially susceptible to catching ringworm, it can affect adults as well.

What causes ringworm?

Ringworm is caused by a fungus that grows on the skin. Once the fungus is established, it spreads out in rings. The centre of the ring may clear up, while a new ring of infection develops at the edge of the old ring.

Children are most likely to get ringworm. Ringworm of the scalp can spread from child to child when children share hats, combs, or brushes. Ringworm of the body can be spread on towels, clothing, or sports equipment. Personal hygiene is important in preventing the spread of ringworm. Dogs and cats can also be infected with ringworm, and they can pass it to people through direct contact.

What are the symptoms of ringworm?

Ringworm of the scalp:

• Dry, brittle hair or hair loss in patches
• Severe itching
• Red-ringed patch of small blisters or scaly skin

Ringworm of the body:

• Red-ringed patch of small blisters or scaly skin
• Severe itching is sometimes present

Consult your practice nurse or doctor if you have a red-ringed skin infection, severe itching of the skin or scalp, a scaly rash or hair loss.

How do I know if I have ringworm?

Your doctor will probably recognise the characteristic rash of ringworm. However, he or she may also:

• Look at the infection with a special ultraviolet light that can detect traces of fluorescent materials that occur in a ringworm infection.
• Scrape an area of affected skin and look at the sample under the microscope.
• Take a sample of skin scrapings for culture, to find out which fungus is causing the infection in order to select the most effective antifungal medicine.

What are the treatments for ringworm?

Your doctor may prescribe an antifungal medication. These drugs work to kill fungi and prevent the condition from coming back. You may use the antifungal agent on your skin as a medicated shampoo, powder, cream or lotion; or you be given a tablet so the medicine can spread throughout your body. You may be prescribed a combination of these treatments.

Many antifungal medications, such as miconazole or clotrimazole, are available over the counter at a lower dose and may be cheaper than a prescription. Ask your doctor whether you can use one of these or whether prescription-strength medicine is necessary.

How can I prevent ringworm?

Good personal hygiene helps prevent the spread of ringworm. Teach your child to practise good hygiene and generally not to share combs, brushes, or hats. Children also shouldn't share towels, clothes, or sports equipment that haven't been properly cleaned.

Ringworm can also be transmitted from an infected dog or cat, so avoid animals who look mangy or have bald spots in their coats. If you have an animal that you think may have ringworm, take it to the vet for treatment.