Ringworm

Ringworm of the scalp is the most common fungal infection in children ; it usually affects them from two years of age to ten. (Fewer than five percent of cases of ringworm of the scalp occur in adults.)

Why is it called "ringworm"?

Ringworm lesions found on the skin (tinea corporis) are scaly and ring-shaped with a central clearing and a raised border. Due to the appearance of the lesion, the fungal infection is commonly called ringworm. Many people, mistakenly, believe the infection is caused by an infestation of a worm. There is no worm burrowed under the skin.

How do people get it?

Most cases of ringworm involving the scalp are due to a fungus that is passed from person to person. Very few of today's fungal infections that involve the scalp are due to fungus from pets, as was the case a decade ago. The fungus can be passed from fallen hairs, dandruff and shared combs, towels or hats.

What does it look like?

The fungal infection can begin as dandruff, areas of baldness, and/or areas of redness on the scalp with associated swelling and pus bumps. In some cases, enlarged lymph nodes in the neck may be felt.

How is it diagnosed?

The diagnosis of fungal infection is suspected by the appearance of the scalp and can be verified by a special examination of dandruff and hairs under the microscope and by doing a fungal culture. The fungal culture usually grows the fungus in three to four weeks. If the clinical examination is suggestive of ringworm and the microscopic examination is positive, treatment may be started while awaiting the results of the fungal culture. Depending on the results of the fungal culture, the patient will then be instructed to continue the treatment, change the treatment or stop it.

How is it treated?

When the diagnosis of ringworm of the scalp is made, an oral (by mouth) anti-fungal medication should be used for six to eight weeks -- or longer if the infection is still present. If your doctor chooses to use some of the newer medications, treatment may need to last only four weeks. Currently, we recommend the use of a selenium sulfide 2.5% shampoo; this treatment decreases the ringworm's contagious period to approximately two weeks. (Note: We recommend that no oil should be applied to the hair after shampooing, because the oil slows the clearing of ringworm.)

In light of the fact that the condition is contagious for as long as two weeks after the shampoo treatment is begun, other children should be kept from contacting the hair, combs, towels or hats of the affected child. However, if the child's head is entirely covered, he or she can attend school or play with other children during that first two weeks.

We also recommend that all family members or close contacts should be examined for the possibility of ringworm infection on the body or scalp.


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Related glossary terms