Ringworm



Ringworm, or tinea (TIH-nee-uh), is a fungal infection of the skin, scalp, or nails. It usually causes red, dry, flaky skin.

KEYWORDS

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Athlete's foot

Dermatophyte Jock itch

Microsporum

Tinea

Trichophyton

What Is Ringworm?

Despite its name, ringworm is not caused by a worm but by mold-like fungi known as dermatophytes (dur-MAH-toh-fites) that thrive in the top layer of the skin, in the scalp, and in nails. Several different but related types of fungi, including those in the Trichophyton and Microsporum species, cause ringworm infection on different parts of the body. All of these infections are known as tinea infections.

Fungal infections take their names from the part of the body where they occur, so tinea corporis is ringworm on the body; tinea unguium is ringworm of the nails; tinea capitis is ringworm of the scalp; tinea cruris is ringworm of the groin (commonly called jock itch); and tinea pedis is ringworm of the feet (also known as athlete's foot). The same fungi that infect humans can infect cats and dogs as well, and people can contract the disease from both people and pets.

Damaged skin is more vulnerable to infection, as is skin in warm, moist areas. When the fungus takes hold, it typically causes a ring-like rash of red, flaking skin. The border of the rash may be raised, as if a worm were under the skin. The rash's shape and this raised edge led people to call the infection ringworm. When the nails are infected, they usually become yellow, thickened, and brittle.

Is Ringworm Common?

Ringworm is widespread in many countries, including the United States. Tinea corporis and tinea capitis infections most often occur in children, although they are found in people of all ages. The other types of ringworm, especially jock itch and athlete's foot, are more common in adolescents and adults.

How Do People Contract Ringworm?

Ringworm is contagious and spreads through direct contact with an infected person or pet. People also can contract the fungus from soil or from surfaces and things that an infected person has touched, such as toys, a pillow, or the locker room floor. Once someone is infected, that person is contagious until the telltale rash starts to shrink. The fading of the ring indicates that the fungus is no longer present.

Latin Lesson

Capitis (KAH-pih-tis): from the Latin word for head

Corporis (KOR-poor-us): the Latin word for body

Cruris (KRU-ris): from the Latin word for leg

Pedis (PEE-dis): the Latin word for foot

Unguium (UN-gwee-um): from the Latin word for nail

How Do People Know They Have Ringworm?

As anyone who has had the infection knows, the symptoms of ringworm are annoying rather than serious. The most common signs are itching around the infected area, dry skin, and a red, ring-shaped rash. Over time the borders of the rash spread outward and the center clears, leaving a circle of red around normal skin. Sometimes the central patch in the rash is filled with pus * , and the borders may be dry and scaly or moist and crusty.

This child has the red, ring-shaped rash characteristic of ringworm. Ringworm is caused by mold-like fungi, not by a worm as the name would suggest. Custom Medical Stock Photo, Inc.
This child has the red, ring-shaped rash characteristic of ringworm. Ringworm is caused by mold-like fungi, not by a worm as the name would suggest.
Custom Medical Stock Photo, Inc.

Ringworm on the scalp can cause a temporary bald patch or areas of scaly, flaky skin, occasionally with a red, swollen spot. Infected nails become yellow, thickened, and brittle, and athlete's foot often appears as red, cracked, peeling skin between the toes.

How Do Doctors Diagnose Ringworm?

In many infected patients, doctors can identify tinea just by looking at the skin, scalp, or nails. To confirm the diagnosis, the doctor may take a scraping of the suspect area to be examined under a microscope for signs of the fungus. The scraping also can be cultured * to see if any fungi grow from it. Because some types of fungi glow under ultraviolet * (UV) light, the doctor may shine a UV lamp on the rash to see if any part of it lights up. This can help identify the fungus causing the infection.

How Is Ringworm Treated?

Doctors prescribe antifungal cream, ointment, or shampoo for most cases of infection. More advanced cases also may require oral (by mouth) medicine, including all cases of tinea capitis and tinea unguium.

Patients typically need to use the cream, ointment, or shampoo for at least 2 weeks. However, some patients may need to use medicine for several weeks or months, depending on the extent and location of the infection. Beyond that, it may take even more time for skin to heal completely or for healthy nails and hair to grow back.

Ringworm may be irritating, but it causes almost no complications. Without treatment, the infection can linger for many months, and infected nails may fall off. Sometimes areas that have been attacked by the fungus develop infection from bacteria because the damaged skin is more vulnerable.

Can Ringworm Be Prevented?

The best way to prevent ringworm is to practice good hygiene, like bathing and changing underclothes every day. Keeping the skin clean and dry will discourage the fungus from taking hold. Not sharing personal items such as brushes, towels, and clothing (especially gym shoes) will limit the spread of ringworm between people. In addition, washing an infected person's clothing and bedding frequently can help keep the infection from spreading to others. If a household pet develops ringworm, doctors advise the family to talk to a veterinarian and avoid direct contact with the animal, like cuddling and patting, until the rash heals.

* pus is a thick, creamy fluid, usually yellow or greenish in color, that forms at the site of an infection. Pus contains infection-fighting white cells and other substances.

* cultured (KUL-churd) means subjected to a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Typically, within days the organisms will grow and can be identified.

* ultraviolet light is a wavelength of light beyond visible light; on the spectrum of light, it falls between the violet end of visible light and X rays.

Athlete's foot can flourish when the skin on the feet, especially between the toes, stays moist. Removing shoes and socks to allow moisture from sweat to dry, carefully drying feet after showering, and changing socks daily can help ward off the fungus. Wearing slip-on sandals instead of going barefoot in public places such as locker rooms and gym showers can reduce the risk of picking up tinea from surfaces an infected person has touched.

See also
Fungal Infections
Skin and Soft Tissue Infections

Resources

Organization

U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894. The National Library of Medicine has a website packed with information on diseases such as ringworm, consumer resources, dictionaries and encyclopedias of medical terms, and directories of doctors and helpful organizations.
Telephone 888-346-3656
http://www.nlm.nih.gov

Website

KidsHealth.org . KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children's health. It contains articles on a variety of health topics, including ringworm.
http://www.KidsHealth.org

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