Last Reviewed: October 2011

What is ringworm?

Ringworm is a skin infection caused by a fungus that can affect the scalp, skin, fingers, toe nails or foot.

Who gets ringworm?

Anyone can get ringworm. Children may be more susceptible to certain types of ringworm than adults.

How are ringworm infections spread?

Transmission of these fungal agents 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.

What are the symptoms of ringworm infections?

Ringworm of the scalp usually begins as a small pimple which becomes larger in size and leaves scaly patches of temporary baldness. Infected hairs become brittle and break off easily. Occasionally, yellowish cuplike crusty areas are seen. With ringworm of the nails, the affected nails become thicker, discolored and brittle, or they 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.

How soon do symptoms appear?

The incubation period is unknown for most of these agents, 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.

Does infection with ringworm make a person immune?

Since so many species of fungus can cause ringworm, infection with one species will not make a person immune to future infections.

What is the treatment for ringworm infections?

Your doctor may prescribe a fungicidal material to swallow as tablets or powders that can be applied directly to the affected areas. Griseofulvin is commonly prescribed for treating fungus infections.

What can be done to prevent the spread of ringworm?

Towels, hats and clothing of the infected individual should not be shared with others. Young children who are infected should minimize close contact with other children until effectively treated. When multiple cases occur, seek advice from your local health department.