Ringworm (Dermatophytosis)

What is ringworm?

Ringworm is a contagious fungus infection that can affect the scalp, the body (particularly the groin), the feet, and the nails. Despite its name, it has nothing to do with worms. The name comes from the characteristic red ring that can appear on an infected persons skin. Ringworm is also called “dermatophytosis” and “tinea”.

Who gets ringworm?

Ringworm is a common skin disorder, especially among children, but it may affect people of all ages, as well as animals. Anyone who is exposed to an infected person, animal, or spores within the environment is at risk of becoming infected.

How is ringworm spread?

The fungus that causes ringworm can spread through direct skin-to-skin contact with infected people or animals.  Ringworm can also spread indirectly, such as by contact with objects or surfaces that an infected person or pet has touched (e.g., hats, combs, brushes, bed linens, towels, stuffed animals, telephones, gym mats, shower stalls, etc.). In rare cases, ringworm can be spread by contact with soil.

What are the symptoms of ringworm?

Ringworm usually starts as a small area of redness and scaling of the skin that spreads outwards, leaving scaly patches of temporary baldness. The area is sometimes itchy; infected hairs may be brittle and break off easily. Ringworm of the foot (“athletes foot”) appears as a scaling or cracking of the skin, especially between the toes. Ringworm of the nails causes the affected nails to become thick, discolored, and brittle. In domestic animals, ringworm can cause a variety of symptoms, but most cases show scaling and patches of hair loss. Some animals may be carriers, but show no signs or symptoms of infection.

How soon after exposure do signs or symptoms appear?

Depending on the specific fungus, signs or symptoms usually occur within one to two weeks of exposure.

Does a past ringworm infection make a person immune?

A previous fungal skin infection does not provide immunity; therefore, re-infection can occur.

How is ringworm diagnosed?

Some cases can be diagnosed by the appearance of the skin rash. Examining an affected area with an ultraviolet light (Wood’s lamp) may show some types of fungal skin infections.  Skin scrapings or hair from the affected area may be examined under a microscope; laboratory testing can confirm the diagnosis.

What is the treatment for ringworm?

Treatment of ringworm usually involves a topical anti-fungal medicine. Oral agents, such as griseofulvin, terbinafine, or itraconzaole may also be considered.

How can dermatophytosis be prevented?

Maintain good hygiene and do not share personal items. Keep common-use areas clean, especially in schools, daycare centers, gyms, and locker rooms. Disinfect sleeping mats and gym mats after each use.  Launder items that have had contact with an infected person in hot water. Affected animals should be seen by a veterinarian.

November 2006 Ringworm Fact Sheet