Ringworm of the Skin

Topic Overview

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This topic is about ringworm of the skin, groin, or hands. For information about other fungal infections, see the topics Athlete's Foot, Diaper Rash, Fungal Nail Infections, and Ringworm of the Scalp or Beard.

What is ringworm of the skin?

Ringworm of the skin is an infection caused by a fungus.

Jock itch is a form of ringworm that causes an itchy rash on the skin of your groin area. It is much more common in men than in women. Most people get it by accidentally spreading the fungus that causes athlete's foot to their own groin area.

What causes ringworm?

Ringworm is not caused by a worm. It is caused by a fungus. The kinds of fungi (plural of fungus) that cause ringworm live and spread on the top layer of the skin and on the hair. They grow best in warm, moist areas, such as locker rooms and swimming pools, and in skin folds.

Ringworm is contagious. It spreads when you have skin-to-skin contact with a person or animal that has it. It can also spread when you share things like towels, clothing, or sports gear.

You can also get ringworm by touching an infected dog or cat, although this form of ringworm is not common.

What are the symptoms?

Ringworm of the skin usually causes a very itchy rash. It often makes a pattern in the shape of a ring , but not always. Sometimes it is just a red, itchy rash.

Jock itch is a rash in the skin folds of the groin. It may also spread to the inner thighs or buttocks.

Ringworm of the hand looks like athlete's foot. The skin on the palm of the hand gets thick, dry, and scaly, while skin between the fingers may be moist and have open sores.

How is ringworm of the skin diagnosed?

If you have a ring-shaped rash, you very likely have ringworm. Your doctor will be able to tell for sure. He or she will probably look at a scraping from the rash under a microscope to check for the ringworm fungus.

How is it treated?

Most ringworm of the skin can be treated at home with creams you can buy without a prescription. Your rash may clear up soon after you start treatment, but it's important to keep using the cream for as long as the label or your doctor says. This will keep the infection from coming back. If the cream doesn't work, your doctor can prescribe pills that will kill the fungus.

If ringworm is not treated, your skin could blister, and the cracks could become infected with bacteria. If this happens, you will need antibiotics.

If your child is being treated for ringworm, you don't have to keep him or her out of school or day care.

Can you prevent ringworm?

To prevent ringworm:

• Don't share clothing, sports gear, towels, or sheets. If you think you have been exposed to ringworm, wash your clothes in hot water with special anti-fungus soap.
• Wear slippers or sandals in locker rooms and public bathing areas.
• Shower and shampoo well after any sport that includes skin-to-skin contact.
• Wear loose-fitting cotton clothing. Change your socks and underwear at least once a day.
• Keep your skin clean and dry. Always dry yourself completely after showers or baths.
• If you have athlete's foot, put your socks on before your underwear so that fungi do not spread from your feet to your groin.
• Take your pet to the vet if it has patches of missing hair, which could be a sign of a fungal infection.

Ringworm can come back. To prevent this, use talcum or other drying powder on the affected area every day.

If you or someone in your family has symptoms, it is important to treat ringworm right away to keep other family members from getting it.

Frequently Asked Questions

Cause

Ringworm infection is caused by a fungus. Fungi (plural of fungus) that cause ringworm live and multiply on the outer layer of skin. Ringworm is not caused by a worm or other parasite.

Fungi are present everywhere in our environment, including on the human body. They thrive in warm, moist areas, such as locker rooms and swimming pools, and in skin folds. You can get ringworm of the skin by sharing contaminated towels, clothing, and sports equipment, and by direct contact with an infected person. Ringworm is common among wrestlers, probably because of the skin-to-skin contact.¹

Ringworm of the skin (tinea corporis) is most commonly caused by the fungus Trichophyton rubrum, which spreads from one person to another. It can also be caused by Microsporum canis, which is spread by cats and dogs. This type is less common but causes more severe infection.

People often get ringworm of the groin ("jock itch") by accidentally spreading athlete's foot fungus to their own groin area. People with athlete's foot also commonly spread it to their hands (tinea manuum).

Some people are more likely to get (susceptible to) fungal infections than others. The tendency to get fungal skin infections or to have them return after treatment seems to run in families.

Symptoms

Most ringworm infections cause a rash that may be peeling, cracking, scaling, itching, and red. Sometimes the rash forms blisters, especially on the feet. See a picture of a typical ringworm skin rash .

Symptoms of ringworm of the body include a rash:

• On the chest, stomach, arms, legs, or back.
• With edges that are red and scaly or moist and crusted. The rash also may have small bumps that look like blisters. The center of the rash may be clear, giving it a ring-shaped appearance, or there may be a cluster of red bumps.
• That may form large, round patches.

Symptoms of ringworm of the face include a rash:

• On the face, the ears, or both.
• With a border that may not be very distinct.
• That may get worse after being in the sun.

Symptoms of ringworm of the groin (jock itch) include a rash:

• In the groin, skin folds, inner thighs, or buttocks. The rash usually does not occur on the scrotum or penis.
• With edges that are very distinct and may be scaly or have bumps that look like blisters.
• That may have a red-brown center.

Jock itch and athlete's foot frequently occur at the same time.

Symptoms of ringworm on the hand include a rash:

• On the palm that may be mistaken for eczema.
• On the palm that is thickened, dry, and scaly, similar to athlete's foot, while skin between the fingers may be moist and have open sores.
• On the back of the hand that is red and scaly, with edges that have bumps that look like blisters.

Fingernails can also be infected. For more information, see the topic Fungal Nail Infections.

Ringworm of the skin may be confused with other conditions with similar symptoms, such as eczema or psoriasis.

What Happens

Ringworm of the skin can start as a small patch of itchy, red, or scaling skin. The rash can spread and cover a large area.

Clothing that rubs the skin can irritate the rash. Sweat, heat, or moisture in the air (humidity) can make the itching and infection worse.

As the infection becomes worse, the ring-shaped pattern and red-brown color may become more visible. If not treated, the skin can become irritated and painful. Skin blisters and cracks can become infected with bacteria and require antibiotics.

Ringworm can also spread to other parts of the body, including the feet, nails, scalp, or beard.

After treatment, the rash will go away. But ringworm can return unless you follow steps to prevent it. The tendency to get fungal skin infections or to have them return after treatment seems to run in families.

What Increases Your Risk

Your risk of getting ringworm is higher if:

• You come in contact with a person who has a fungal infection or with a carrier-a person who has the fungi but does not have symptoms.
• You are susceptible to fungal infections or you have had a previous fungal infection.
• You have an impaired immune system due to a disease such as diabetes, AIDS, or cancer.
• You live in a warm, damp climate.
• You wear tight-fitting clothes or you let your skin stay damp for long periods, such as by staying in a wet bathing suit or sweaty workout clothes.
• You are a wrestler.

When To Call a Doctor

If you suspect you have ringworm of the skin, call your doctor if:

• You have patches of skin that are itchy, red, or scaly with bumps that look like blisters, and they have not improved after 2 weeks of treatment with a nonprescription antifungal product.
• Signs of bacterial infection develop. Signs may include:
  • Increased pain, swelling, redness, tenderness, or heat.
  • Red streaks extending from the area.
  • Discharge of pus.
  • Fever of 100 °F (37.8 °C) or higher with no other cause.
• The rash appears to be spreading even after treatment.

Watchful Waiting

Watchful waiting is a wait-and-see approach. If you get better on your own, you won't need treatment. If you get worse, you and your doctor will decide what to do next.

You can treat ringworm at home with medicines you can buy without a prescription. If symptoms do not improve after 2 weeks of treatment with this medicine, call your doctor.

Any persistent, severe, or recurring infection should be checked by your doctor.

Who To See

The following health professionals can diagnose and treat ringworm of the skin:

• Family medicine physician
• Pediatrician
• Dermatologist
• Nurse practitioner
• Physician assistant
• Internist

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

Doctors often can easily recognize ringworm by its ring-shaped rash . Your doctor will probably also look at a skin sample (KOH preparation) under a microscope to confirm that fungus is present.

Tests for ringworm of the skin include:

• A KOH (potassium hydroxide) preparation. This test can help your doctor find out whether a fungus is causing your rash. The doctor will take a sample of your skin by lightly scraping the infected area. The sample is placed on a slide with potassium hydroxide (KOH) solution and gently heated. If fungus cells are present, the doctor can then see them with a microscope.
• A fungal culture (skin culture). This test can identify the type of fungus that is causing your infection. Usually a culture is only done if the diagnosis is difficult or the skin condition is not responding to treatment. This test may take up to 4 weeks, because it takes time for the fungus to grow.

Treatment Overview

Most cases of ringworm of the skin, including jock itch and ringworm of the hand, can be treated with creams or ointments that you put on your skin to kill fungi. These are called topical antifungals. You can get many topical antifungals without a prescription. Brand names include Micatin, Tinactin, Monistat-Derm, Lotrimin, and Lamisil.

You may need to take antifungal pills (oral treatment) if the ringworm does not go away after you have tried different topical antifungals or if the infection is widespread. Oral treatments include azoles such as fluconazole (Diflucan), allylamines such as terbinafine (Lamisil), and griseofulvin (Fulvicin U/F, Grifulvin V).

Your rash may start to clear up soon after you begin treatment, but it is important to use the medicine exactly as the label or your doctor says. This will help keep the infection from coming back. Usually you need to continue treatment for 2 to 4 weeks.

If not treated, ringworm can spread and the skin can become irritated and painful. Skin blisters and cracks can become infected with bacteria. If this happens, you may need to take antibiotics.

What To Think About

You should treat a fungal infection right away. Severe and widespread infections can be hard to treat.

Prevention

To prevent ringworm of the skin:

• Keep your skin clean and dry. Change your socks and underwear at least once a day.
• Wear loose-fitting cotton clothing. Avoid tight underwear, pants, and panty hose.
• Always dry yourself completely after showers or baths. After drying your skin with a towel, allow your skin to air-dry before putting your clothes on. You can also use a hair dryer, set on a cool setting, to dry your skin.
• Do not share clothing, sports equipment, towels, or sheets. If you think you have been exposed to ringworm, wash your clothes in hot water with fungus-killing (fungicidal) soap.
• Wear slippers or sandals in locker rooms, showers, and public bathing areas.
• Shower and shampoo thoroughly after any sport that requires skin-to-skin contact.
• If you have athlete's foot, put your socks on before your underwear so that fungi do not spread from your feet to your groin.
• Take your pet to a veterinarian if it has patches of missing hair, which may be a sign of a fungal infection. Household pets can spread fungi that cause ringworm in people.

To prevent ringworm from returning after treatment, apply talcum or other drying powder to the affected area daily.

Home Treatment

In most cases, you can treat ringworm of the skin with antifungal creams or ointments. Many are available without a prescription. Use a nonprescription antifungal cream with miconazole or clotrimazole in it. Brand names include Micatin, Tinactin, Monistat, and Lotrimin. Terbinafine cream (Lamisil) is also available without a prescription.

• Wash the rash with soap and water, remove flaky skin, and dry thoroughly. For large areas of blistered sores, use compresses such as those made with Burow's solution (available without a prescription) to soothe and dry out the blisters.
• Apply antifungal cream beyond the edge or border of the rash.
• Follow the directions on the package. Don't stop using the medicine just because your symptoms go away. You will probably need to continue treatment for 2 to 4 weeks.
• If symptoms do not improve after 2 weeks, call your doctor.

To prevent ringworm from returning after treatment, apply talcum or other drying powder to the affected area daily.

If your rash does not clear after you have tried different topical antifungals, or if the infection is widespread, you may need prescription antifungal pills.

If you have both athlete's foot and ringworm of your groin or legs, you should treat both infections. This will prevent you from re-infecting your legs or groin with the athlete's foot fungus, when you put on your underwear.

To prevent the spread of infection:

• During treatment, children with ringworm should avoid activities where they may spread the infection to others, such as in gyms or swimming pools.²
• Wrestlers should wear a protective bandage over ringworm rashes when practicing. Typically, wrestlers are not allowed to compete until they have finished 1 week of topical treatment with an antifungal medicine, and they are not allowed to practice if bandaging is not possible. Regular skin inspections should be done before practices, and mats and other equipment should be thoroughly disinfected.¹

Medications

Most ringworm infections of the skin can be treated at home with nonprescription antifungal creams. The rash will usually improve within 2 weeks. But most antifungals need to be used for 2 to 4 weeks to eliminate the fungus.³

If the rash does not improve after you have used an antifungal cream and it is severe and widespread or returns frequently, you may need antifungal pills that your doctor prescribes. When treating ringworm, it is important to finish the full course of medicine prescribed, even if the symptoms have gone away, so that the infection does not return.

Medication Choices

The most common antifungals used to treat ringworm of the skin are:

• Allylamines, such as terbinafine (Lamisil). Allylamines come as creams, pills, and gels. Lamisil is available as a cream without a prescription.
• Azoles. Oral prescription forms include fluconazole (Diflucan) and itraconazole (Sporanox). Some of these medicines are available without a prescription. Brand names include Micatin, Monistat-Derm, and Lotrimin.
• Griseofulvin (Fulvicin U/F, Grifulvin V, Grisactin). Griseofulvin comes in pill form and requires a prescription.
• Other antifungals such as tolnaftate (Tinactin). Tinactin is available without a prescription and comes in lotion, cream, gel, and spray forms.

Clotrimazole/betamethasone (Lotrisone), a combination antifungal and corticosteroid, is sometimes used to treat ringworm that is burning, itchy, and inflamed. This prescription medicine should be used with caution and for no longer than 2 weeks, because complications can occur with long-term use of corticosteroids.

What To Think About

Griseofulvin is the oldest and least expensive of the oral medicines. The newer oral medicines-terbinafine, fluconazole, and itraconazole-require shorter treatment times, which may make it more likely that the person will complete the full course of treatment.

If you take antifungal pills, you will need frequent blood tests to check for liver problems.

If there is no improvement of the skin infection after 2 to 4 weeks of treatment, the rash may not be due to a fungal infection.

Surgery

There is no surgical treatment for ringworm of the skin.

Other Treatment

There is no other treatment for ringworm of the skin.

Other Places To Get Help

Organization

Related Information

• Athlete's Foot
• Fungal Nail Infections
• Ringworm of the Scalp or Beard

References

Citations

1. Adams BB (2002). Tinea corporis gladiatorum. Journal of American Academy of Dermatology, 47(2): 286-290.

2. American Public Health Association (2004). Dermatophytosis. In DL Heymann, ed., Control of Communicable Diseases Manual, 18th ed., pp. 152-159. Washington, DC: American Public Health Association.

3. Hirschmann JV (2006). Fungal, bacterial, and viral infections of the skin. In DC Dale, DD Federman, eds., ACP Medicine, section 2, chap. 7. New York: WebMD.

Other Works Consulted

• American Academy of Pediatrics (2006). Tinea corporis (ringworm of the body). In LK Pickering, ed., Red Book: 2006 Report of the Committee on Infectious Diseases, 27th ed., pp. 656-657. Elk Grove Village, IL: American Academy of Pediatrics.

• Landry GL, et al. (2004). Herpes and tinea in wrestling: Managing outbreaks, knowing when to disqualify. Physician and Sportsmedicine, 32(10): 34-44. Available online: http://www.physsportsmed.com/issues/2004/1004/landry.htm.

• Nelson MM, et al. (2003). Superficial fungal infections: Dermatophytosis, onychomycosis, tinea nigra, piedra. In IM Freedburg et al., eds., Fitzpatrick's Dermatology in General Medicine, 6th ed., vol. 2, pp. 1989-2005. New York: McGraw-Hill.

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