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. Jock itch may be caused by the spread of
athlete's foot fungus to the groin.
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. And 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 help 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, drying your feet last.
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.
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.
Ringworm
infection is caused by a
fungus. Fungi (plural of fungus) that cause ringworm
live and spread 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.
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:
On 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.
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.
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.
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.
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. You will probably 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.
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. Also, when
toweling off after a shower or bath, dry your feet last.
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.
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, 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.
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, people with ringworm of the
body or groin (jock itch) should avoid activities where they may spread the
infection to others, such as in 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
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 get rid of 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 you are 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.
Allylamines, such as terbinafine
(Lamisil). Allylamines come as creams, pills, and gels. Terbinafine also comes
as oral granules, which are little grains that can be sprinkled over food and
easily swallowed. 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.
People who are taking antifungal pills should have a doctor
monitor their blood counts and liver and kidney function during treatment to
watch for any harmful side effects.
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.
The American Academy of Dermatology provides information
about the care of skin, hair, and nails. You can find a dermatologist in your
area by calling 1-888-462-DERM (1-888-462-3376).
American Academy of Family
Physicians
P.O. Box 11210
Shawnee Mission, KS 66207-1210
Web Address:
www.familydoctor.org
The American Academy of Family Physicians produces a
variety of health-related educational materials. Its Web site offers a health
library and bulletin board, news, and comments sections.
KidsHealth for Parents, Children, and
Teens
10140 Centurion Parkway North
Jacksonville, FL 32256
Phone:
(904) 697-4100
Fax:
(904) 697-4125
Web Address:
www.kidshealth.org
This Web site is sponsored by the Nemours Foundation. It
has a wide range of information about children's health, from allergies and
diseases to normal growth and development (birth to adolescence). This Web site
offers separate areas for kids, teens, and parents, each providing
age-appropriate information that the child or parent can understand. You can
sign up to get weekly e-mails about your area of interest.
Adams BB (2002). Tinea corporis gladiatorum.
Journal of American Academy of Dermatology, 47(2):
286–290.
American Public Health Association (2008).
Dermatophytosis. In DL Heymann, ed., Control of Communicable Diseases Manual, 19th ed., pp. 172–179. Washington, DC: American Public
Health Association.
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.
Hall JC (2006). Dermatologic mycology. In JC Hall,
ed., Sauer’s Manual of Skin Diseases, 9th ed., pp.
244–266. Philadelphia: Lippincott Williams and Wilkins.
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.
Verma S, Heffernan MP (2008). Superficial fungal
infection: Dermatophytosis, onychomycosis, tinea nigra, piedra. In K Wolff et
al., eds., Fitzpatrick's Dermatology in General Medicine, 7th ed., vol 2, pp. 1807–1821. New York: McGraw
Hill.
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