Clinical Definition

Ringworm, known medically as tinea, refers to a highly contagious skin infection that is not caused by a worm but by several types of fungi. Tinea corporis is ringworm on the body, for example, and tinea capitis targets only the scalp. These fungi specially thrive on the skin between the toes and in the groin because the areas tend to be warm and damp. Fungi spreads from person to person, but not everyone who has a fungus also acquires the rash.

In Our Own Words

Contrary to popular opinion, ringworm isn’t caused by a worm but by a contagious skin infection cause by fungus. Known as dermatophytes, specific fungi cause infections of the skin, hair and nails and thrive in moist areas, especially where there are skin folds. Dermatophytes can live on your clothing, towels, bedding and other household items. Some dermatophytes can be transmitted to people from dogs and cats as well.

Children are more likely to be affected ringworm on the scalp, or tinea capitis, than adults. Elsewhere on the skin, ringworm grows and spreads out in a circle, presenting like a ring. This infection makes skin red and scaly so it may look like a worm under the skin, but it’s not.