Ringworm is a skin infection caused by a fungus that can affect the scalp, skin, fingers, toenails or foot. In New York City, ringworm is not required to be reported so that the number of people infected each year is unknown.
Anyone can get ringworm. Children may be more susceptible to certain species of ringworm while adults may be more susceptible to other varieties.
Transmission of the fungus can occur by direct skin-to-skin contact with infected people or pets, or indirectly by contact with items such as barber clippers, hair from infected people, shower stalls, or floors.
Ringworm of the scalp usually begins as a small pimple, which becomes larger in size, leaving scaly patches of temporary baldness. Infected hairs become brittle and break off easily. Occasionally, yellowish crusty areas are seen. With ringworm of the nails, the infected nails become thicker, discolored and brittle, or they can become chalky and disintegrate. Ringworm of the body appears as flat, spreading ring-shaped areas. The edge is reddish and may be either dry and scaly or moist and crusted. As it spreads, the center area clears and appears normal. Ringworm of the foot appears as a scaling or cracking of the skin, especially between the toes.
The incubation period is unknown for most types of ringworm, however ringworm of the scalp is usually seen 10 to 14 days after contact and ringworm of the body is seen 4 to 10 days after initial contact.
Since so many species of fungus can cause ringworm, infection with one species will not make a person immune to repeat infections.
Your doctor may prescribe a fungicidal material to swallow as tablets, or powders that can be applied directly to the infected areas. Griseofulvin is commonly prescribed for treating fungus infections.
Towels, hats, and clothing from an infected individual should not be shared with others. Young children who are infected should have minimal close contact with other children until effectively treated.
Last Updated: April 2003