Contrary to its name, ringworm is not caused by worms but by a contagious fungal infection of the skin. It develops as a small, red, raised, round patch that gradually enlarges. The outer ring looks inflamed, while the inside appears to be healthy skin. The condition can develop anywhere on the skin’s dead top layer. Ringworm cannot occur in the mouth or any other area lined with mucous membranes.
Ringworm is most often acquired by direct contact with an infected person or household pet. It can also be caught from touching a contaminated floor, shower or bathtub, or an infected object, such as a brush. Rarely, ringworm can be picked up from infected soil. Dermatophytes--microorganisms found pretty much everywhere--are the mold-like fungi that lead to ringworm.
Ringworm’s distinct scaly, red and itchy ring-like rash generally makes self-diagnosis easy. Since the condition can spread, it’s common to notice more than one patch of ringworm on the body or red rings that overlap. A rash that doesn’t improve or disappear within two weeks--or that becomes excessively red, sore or pussy--may require a doctor visit and professional evaluation.
A nonprescription, topical, antifungal skin cream or ointment is the most common treatment. More severe cases may require a prescription cream or, in some cases, an antifungal drug that usually comes in tablet form. Covering the rash with clothing or an adhesive bandage can help prevent its spread.
Skin fungi grow best in moist, warm areas. To help prevent ringworm, keep your body dry. Wear loose-fitting underwear that won’t trap moisture, and change socks daily. Wear sandals or other protective footwear in moist areas, such as locker rooms, gyms and pools. Also, avoid sharing towels, combs and other personal items.
Other common skin conditions, including eczema and psoriasis, sometimes resemble ringworm, especially in its early stages when the ring is small. If you have questions or concerns--or if you experience a rash accompanied by fever--contact your doctor.