What Is Ringworm? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Ringworm (also called tinea or dermatophytosis) is a very common fungal infection of the skin and nails that has nothing to do with worms. (1) The condition is called ringworm because it tends to cause an itchy, red, circular or ring-shaped rash, according to the Centers for Disease Control and Prevention (CDC). It can occur just about anywhere on the body and has different names depending on which part of the body it affects. Types of ringworm include:

Tinea pedis (Athlete's foot) ringworm on the feet

Tinea cruris (Jock itch) ringworm on the groin, inner thighs, and buttocks

Tinea barbae Ringworm on the beard area

Tinea faciei Ringworm on the face

Tinea manuum Ringworm on the hands

Tinea capitis Ringworm on the scalp

Tinea unguium (Onychomycosis) ringworm on the fingernails and toenails

Tinea corporis Ringworm on other parts of the body, such as the arms or legs

The specific symptoms of ringworm depend on the location of the infection. They typically include: (2)

• Itchy skin
• Red, scaly, or cracked skin
• A ring-shaped rash
• Hair loss

Symptoms of ringworm can be different depending on the specific part of the body that’s affected:

• Tinea pedis, or athlete’s foot Skin may peel or become swollen, red, and itchy between the toes (particularly between the pinky toe and the one next to it). The soles and heels of the feet may also be affected. In severe cases, blistering of the feet can occur.
• Tinea cruris, or jock itch Itchy, scaly red spots usually appear on the inner thighs.
• Tinea barbae Scaly, itchy red spots may be visible on the cheeks, chin, and upper neck. The spots may become crusty or fill up with pus, and hair loss may occur.
• Tinea faciei Scaly, itchy plaques may be visible on the cheeks. Sometimes pustules and crusting are seen.
• Tinea manuum Palms may have dry skin with deep cracks, and ring-shaped patches may appear on the back of the hand. (3)
• Tinea capitis Typically looks like a scaly, red, circular bald spot on the scalp that is also itchy, and it can grow in size. Ringworm on the scalp is more common in children than adults. (2)
• Onychomycosis Nails become thick and abnormal in shape and color, and one or several nails may be affected. (3) Onychomycosis often occurs in people who have athlete’s foot for a prolonged period.
  

There are about 40 different species of fungi — in the Trichophyton, Microsporum, and Epidermophyton genera — that can cause ringworm. (1)

Ringworm is contagious even before symptoms appear, according to the Mayo Clinic. (4)

The condition is caused by mold-like fungi called dermatophytes, says the U.S. National Library of Medicine. (5) Like other types of fungi, dermatophytes thrive in warm, moist areas. You can catch ringworm by:

• Having direct, skin-to-skin contact with affected areas of an infected person's body
• Touching items that have the fungi on them, such as clothing, combs, pool surfaces, and shower floors
• Playing with pets. Cats and dogs, and especially kittens and puppies, are common carriers, according to the National Institutes of Health (NIH). (6) Touching other infected animals, such as cows, goats, pigs, and horses, can also lead to an infection. Sometimes an animal’s infection looks like an area where the fur is patchy or scaly, but the signs may not always be visible. Be sure to take your pet to the veterinarian if you think it might have an infection.

Risk Factors

You're more likely to develop ringworm if you: (5)

• Have wet skin for a long period of time (which can be due to sweating)
• Have nail or skin injuries
• Do not bathe or wash your hair regularly
• Have close contact with other people or animals
• Participate in contact sports such as wrestling
• Live or spend time in a hot, humid, tropical climate (7)
• Share towels, clothes, razors, and other items without disinfecting or washing them
• Are obese
• Have diabetes
• Wear clothing that is too tight and chafes your skin
• Don’t wash and dry your feet well before putting on shoes and socks after using a locker room or pool
• Have a weak immune system (4)

Your healthcare provider might be able to tell whether you have a ringworm infection just by looking at it. (8) They also might take skin scrapings from the affected area.

The American Academy of Family Physicians notes that diagnosing ringworm can be a little tricky, because it often resembles other conditions. (9) For example, tinea corporis might be confused with eczema, psoriasis, or seborrheic dermatitis; tinea capitis might be confused with alopecia areata; and ringworm of the toenails can look like dystrophic toenails (changes in texture and composition) caused by trauma to the nails. A ringworm diagnosis can be confirmed with a fungal culture.

Prognosis of Ringworm

Pretty much every case of ringworm can be successfully treated, whether it’s with over-the-counter or prescription medication. (10) Taking preventive measures can help you avoid spreading ringworm to other parts of your body or reinfecting yourself or others in the meantime.

Ringworm symptoms usually appear between 4 and 14 days after the skin comes into contact with dermatophytes. (2)

Antifungal medicine may clear up a ringworm infection quickly, eliminating symptoms in just a few days. (10)

When treated with nonprescription antifungal medication, ringworm on the skin like tinea pedis (athlete’s foot) and tinea cruris (jock itch) typically clear up within two to four weeks. (11) Tinea capitis (ringworm on the scalp) usually needs to be treated with prescription antifungal medication for one to three months.

Some types of ringworm can be treated with over-the-counter medications, but other forms require prescription antifungal medication. (11)

Medication Options

Treatment of ringworm depends on the location of the infection. Nonprescription antifungal creams, lotions, or powders that can treat tinea pedis (athlete’s foot) and tinea cruris (jock itch) include:

• Clotrimazole (Lotrimin, Mycelex)
• Miconazole (Aloe Vesta Antifungal, Azolen, Baza Antifungal, Carrington Antifungal, Critic-Aid Clear, Cruex Prescription Strength, DermaFungal, Desenex, Fungoid Tincture, Micatin, Micro-Guard, Mitrazol, Remedy Antifungal, Secura Antifungal)
• Terbinafine
• Ketoconazole (Xolegel)

Prescription antifungal medications that can treat ringworm on the scalp include:

• Griseofulvin (Grifulvin V, Gris-PEG)
• Terbinafine
• Itraconazole (Onmel, Sporanox)
• Fluconazole (Diflucan)

Alternative and Complementary Therapies

Tinea cruris (jock itch) can typically be treated with over-the-counter topical medications. (12) Dermatologists also advise wearing breathable, cotton underwear. To relieve the symptoms of jock itch, the AAD recommends applying a cool, wet washcloth to the area for 20 to 30 minutes two to six times a day. (13) It’s important to use a clean washcloth each time and to use it only on the itch, and to wash it in hot, soapy water before using it again.

There has been some research into the use of herbal remedies in treating ringworm, but it has been mostly limited to animals. A study in the Hong Kong Medical Journal found that a topical herbal formula of traditional Chinese medicines with antifungal properties was effective in treating athlete’s foot in guinea pigs, though not as effective as a topical antifungal medication. (14) And a study in Mycoses found that an herbal formula of essential oils, applied topically, appeared to limit fungal growth in sheep affected with ringworm. (15) The German organization Informed Health Online notes that applications of tea tree oil have been recommended for athlete’s foot, but that there’s not much scientific evidence to support these recommendations. (16)

Prevention of Ringworm

Ringworm can be challenging to prevent, but there are a number of simple steps you can take to reduce your risk, or to prevent the infection from spreading to other areas of your body or to other people. (4)

• Avoid sharing personal items such as clothing, towels, hairbrushes, and sports gear.
• Don’t wear heavy clothing for long periods of time if you’re in a warm, humid climate.
• Try to avoid excessive sweating.
• Wash your hands often and well.
• Shower right after playing sports and keep your uniform and gear clean.
• Avoid infected animals, and have your pets or animals checked for ringworm.
• Change your clothes, including your underwear and socks, every day, and wash them before wearing them again. (10)
• Shower after exercising.
• Wear waterproof shoes in locker rooms, public or shared showers, and pool areas.
• Disinfect or throw out clothes and items that may be infected with ringworm, or that you wore while you had ringworm.
• Wash towels and bedding that you use while you have ringworm in hot, soapy water.

A fungal infection rarely spreads below the surface of the skin, so it's very unlikely to cause serious illness. (4) But untreated ringworm can sometimes cause the fungus to grow in deeper levels of the skin. Known as Majocchi’s granuloma, this rash consists of raised bumps and pustules and can be difficult to treat.

People with weak immune systems, like those who have HIV/AIDS, may find it challenging to get rid of ringworm. (4)

An estimated 10 to 20 percent of the world’s population is affected by fungal skin infections, according to a report published by the Cochrane Database of Systematic Reviews. (17)

Some types of ringworm are more common in children than adults, according to Johns Hopkins Medicine. (18) The most common infections in younger kids are tinea corporis (body ringworm) and tinea capitis (scalp ringworm), while teens and adults more commonly develop tinea cruris (jock itch), tinea pedis (athlete’s foot), and tinea unguium (ringworm of the nails). (9) Tinea cruris is more common in males and very rare in females. (18) Athlete’s foot is also more common in males. Tinea capitis occurs mostly in children from ages 2 to 10, and is rarely found in adults. Tinea unguium (ringworm of the nails) occurs more often in adolescents and adults rather than young children.

Ringworm often resembles other conditions, including eczema (atopic dermatitis). Eczema is a condition that makes your skin red and itchy. (19) Like ringworm, it's common in children, but anyone can get eczema. Symptoms include itching, and red to brownish-gray patches on the skin.

HIV (human immunodeficiency virus) is a virus that attacks the immune system, making you more vulnerable to other infections and diseases (including ringworm). (20) It is spread by contact with certain bodily fluids of a person with HIV. Without treatment, HIV can lead to AIDS (acquired immunodeficiency syndrome).

RELATED: What Is Eczema (Atopic Dermatitis)? Symptoms, Causes, Diagnosis, Treatment, Prevention

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Centers for Disease Control and Prevention

The CDC is the nation's health protection agency. Their website offers information about the symptoms, diagnosis, treatment, and prevention of ringworm.

American Academy of Dermatology

The AAD is the largest dermatological association, with a membership of more than 20,500 physicians worldwide. Their website provides information about the symptoms, causes, and treatment of ringworm, along with self-care tips.

Mayo Clinic

Mayo Clinic is a nonprofit organization that performs clinical practice, education, and research. Their website offers information about symptoms, causes, diagnosis, and treatment of ringworm.