Spot the rash of ringworm

Although it’s called ringworm, this rash isn’t caused by a worm.  In fact, it barely looks like a worm. Otherwise known as tinea corporis, the patch of ringworm is usually a flesh or light-pink colored, slightly scaly oval with raised, red edges.

Caused by a fungus, sometimes the patch is itchy. The same organism also causes athlete’s foot (tinea pedis), jock itch (tinea cruris),  and scalp infections (tinea capitis).

Ringworm falls into the mostly-harmless-but-annoying category of skin rashes (cover it up and no one will notice). Your child’s doctor will diagnose the rash by examining your child’s skin. To treat the rash, apply antifungal medication until the rash is gone for at least 48 hours (about two to three weeks duration). Clotrimazole (for example, brand name Lotrimin) is over-the-counter and is applied twice daily. You will find it in the anti-athlete’s foot section.

On the scalp, ringworm causes hair loss where the rash occurs.  Treatment is not so straight forward. Ringworm on the scalp requires a prescription oral antifungal medication for several weeks. The fungus on the scalp lives not only on the skin, but also in hair follicles. So, topical antifungals fail to reach the infection.

Ringworm spreads through direct contact. Wrestling teams are often plagued with this infection. Cats may carry ringworm. If your family cat has signs of feline ring worm such as patches of hair loss, take him to the vet for diagnosis.

If your child’s “ringworm” fails to improve after a week of applying antifungal medication, have your child’s doctor examine (or re-examine) the rash. Other diagnoses we keep in mind include eczema and granuloma annulare. If the rash continues to enlarge we consider Lyme disease.

Kids are allowed to attend school and daycare with ringworm once treatment is started. Wrestlers are advised to cover the rash for the first three days of treatment.

The sooner you start to treat ringworm, the more quickly it resolves. Just remember, “the early bird catches the…” oh, never mind.

Naline Lai, MD and Julie Kardos, MD
©2017 Two Peds in a Pod®, updated from 2012