What is pinworm infection?

Pinworms in children: Overview

Pinworms are a type of parasite. They live in the lower digestive system of humans. They survive on nutrients from the food we eat.

People are most likely to get pinworms if they swallow their eggs. This can happen if a person with pinworms scratches around the anus. Then the person gets eggs on his or her hands or under the fingernails. You can then get pinworms if you touch that person or if you touch something he or she touched.

Some people feel embarrassed about having "worms." But pinworm infections can happen to anyone and are common in children. They don't mean that your child isn't clean.

It's easy to treat a pinworm infection. If more than one person in your home gets pinworms, or if your child's infection keeps coming back, make sure to treat everyone in your home.


Pinworms are a type of parasite that lives in the digestive system of humans. Most people get infected by touching something that has pinworm eggs on it and then swallowing them. Pinworms can be annoying, but they rarely cause serious health problems.

Treatment can kill pinworms. It also helps keep you from getting infected again and from spreading the infection to other people.

What are the symptoms of pinworms?

Many people with pinworms don't have symptoms and don't know that they're infected. When symptoms occur, the most common ones are:

  • Itching around the anus.
  • Restless sleep, because itching is often worse at night.

Pinworms can be annoying. But they don't carry disease, and they rarely cause serious health problems. Sometimes people get a skin infection from scratching.

How are pinworms treated?

You can treat pinworms with over-the-counter or prescription medicine that kills the worms. Treatment can help keep you from getting infected again and from spreading the infection to other people.

You will probably need two doses, 2 weeks apart. That's because the medicine kills the worms but not the eggs. The second dose will kill any worms that hatch after the first treatment.

Pinworm medicine may not be safe for children younger than 2 and women who are pregnant or breastfeeding. So to reduce their risk of infection, a doctor may recommend that all other household members be treated with medicine.

How can you help prevent pinworms?

Pinworms spread easily and often come back. To reduce your chances of spreading the infection or getting infected again:

  • Wash your hands carefully and often. Teach your children to do the same, especially after they use the toilet and before they handle food.
  • Keep your fingernails short, and don't scratch the itch. Wearing gloves at night may help prevent scratching.
  • Bathe or shower every day.
  • Don't share or reuse towels or washcloths.
  • Change your underwear and bedding each morning.
  • Wash clothes, bedding, and towels regularly. Dry them in a hot dryer.

If anyone in your household gets pinworms again, the whole family may need to take medicine.

How are pinworms diagnosed?

To find out if you have pinworms, your doctor will ask about your past health and check the skin around your anus.

The doctor may ask you to do a transparent tape test at home. To do the test, you press a piece of clear, sticky tape on the skin around your anus in the morning before you get up. The doctor will put the tape under a microscope to look for pinworm eggs. You might need to repeat this test a few times.

How can you care for yourself when you have pinworms?

Take your medicine as prescribed. Wash your hands well and often. Cut your fingernails short, and keep them trimmed. This can keep eggs from sticking under your nails. Wash clothes, towels, and bedding often. Use hot water and a hot dryer. Don't scratch. Bathe or shower every day, especially cleaning well around the anus.

What are pinworms?

Pinworms are a type of parasite that lives in the digestive system of humans. They are common throughout the world.

Adult pinworms are about 0.5 in. (12.7 mm) long and look like little white threads. Pinworm eggs are so tiny, you'd need a microscope to see them.

What causes pinworms?

Most people get infected by accidentally swallowing pinworm eggs. Anyone can get pinworms, but they are most common in school-aged children. They are usually spread like this:

  • A child swallows pinworm eggs, and they travel to the child's intestines. In about a month, the eggs hatch into worms. At night the female worms crawl out the rectum and lay eggs around the child's anus.
  • When the worms lay eggs, it can cause itching. If the child scratches, the eggs can cling to the child's fingers and get stuck under the fingernails.
  • The eggs then stick to things the child touches, such as clothing, dishes, toys, and furniture. The eggs can live 2 to 3 weeks outside the body.
  • When you touch something the child has touched, the eggs get on your hands. Then if you touch food or your mouth, you can swallow the eggs. This starts the cycle over again.

Pinworms spread easily in homes, day care centers, schools, and other places where groups of people spend time together. So if one person in your family has pinworms, others probably do too.

It's possible to get pinworms by inhaling airborne eggs, but this is rare. It's also rare to get pinworms from a swimming pool.

Pinworms are spread from person to person. Pets don't get pinworms and can't spread them to humans.

Pinworms: When to call

Call your doctor now or seek immediate medical care if:

  • You develop other symptoms, including:
    • A fever or belly pain.
    • Redness, tenderness, or swelling in the genital area.
    • Itching in the genital area or vagina.
    • Pain when you urinate.
    • A frequent or urgent need to urinate.
    • Lack of control of urination.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • Your doctor gave you medicine, and the pinworms have not cleared up as expected (usually within 4 to 6 weeks).
  • You are having side effects from medicine for pinworms.

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The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.