Ringworm is a common fungal infection that can affect several areas of the body, including the scalp, feet, groin, other areas of skin, and also the nails. The specific type of fungus that causes ringworm (which is also known as tinea) grows in moist, warm environments.

Tinea lives on the outermost layer of the skin, hair and nails and feeds on the cells there. As the fungus multiplies on the skin, it spreads out in a circle, leaving a distinctive ring-like pattern. Despite its name, there is no worm present under the skin in patients with this infection.

Ringworm is contagious, and people can become infected with the causative fungus in many ways. Direct contact with an infected person or animal can transmit the fungus. Direct contact with contaminated, damp surfaces (e.g., public showers, locker room floors) and other contaminated items (e.g., combs, unwashed clothing) also can result in ringworm infection.

Ringworm is a skin disorder that can affect people of all ages. People with compromised immune systems are more vulnerable to ringworm infection. Other skin conditions (e.g., atopic dermatitis, psoriasis) sometimes can cause symptoms similar to those of ringworm. For this reason, a physician typically performs various tests to make a definitive diagnosis of ringworm.

Some ringworm infections may get better on their own without any treatment. Patients with minor symptoms also may be able to get rid of ringworm using simple self-care measures. In other cases, ringworm infections may require treatment with prescription medications such as antifungal creams or pills.

Several steps can be taken to prevent ringworm. People should avoid close contact with people or animals known to be infected with ringworm. People also are urged to keep their skin and feet clean and dry, to shampoo regularly, and to wear sandals or shoes at gyms, lockers and pools. It is best not to share clothing or personal care items such as towels, brushes and combs.