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Pinworm Infection

Medically reviewed by Last updated on Oct 1, 2023.

What is a pinworm infection?

Pinworms are small, thin, white worms that infect the intestines. At night, these worms enter your child's anus and lay tiny eggs around it. Pinworm infections are most common in children 5 to 14 years old. A pinworm infection may also be called enterobiasis.

What causes a pinworm infection?

Your child may get pinworm eggs from other children or adults who are infected. He or she may get the eggs by touching bedding, clothes, or toilet seats that have eggs on them. Your child may breathe in dust that holds the eggs. The eggs may get into the air by coming loose from bedding and clothing. Your child may scratch his or her anus and then swallow the eggs. This happens if your child puts his or her fingers in his or her mouth. The eggs will grow into pinworms in your child's intestines. The pinworms may stay in your child's intestines for months.

What are the signs and symptoms of a pinworm infection?

Your child may not have any symptoms, or he or she may have any of the following:

  • Itching around the anus that is worse at night
  • Irritability and trouble sleeping
  • Decreased appetite, and losing weight without trying
  • Nausea, vomiting, or diarrhea
  • Abdominal pain
  • Bed wetting or pain during urination
  • Redness or bleeding around your child's anus
  • Urinary tract infection or vaginal infections in females

How is a pinworm infection diagnosed?

Your child's healthcare provider will ask about your child's symptoms. He or she may also examine the area around your child's anus. Your child may need any of the following:

  • A tape test can show if there are any pinworms or eggs around your child's anus. This test is usually done at night or right after your child wakes in the morning. A piece of clear adhesive tape will be patted around your child's anus. Your child's healthcare provider will then look for eggs on the tape using a microscope. This test may need to be done for 3 or more days.
  • Saline swabs are used to wipe around your child's anus. The swab will be sent to a lab to test for pinworm eggs.
  • Skin scrapings taken from under your child's fingernails may also be tested for pinworm eggs.
  • A sample may be tested for pinworm eggs. A sample of your child's bowel movement, urine, or vaginal fluid is viewed under a microscope.

How is a pinworm infection treated?

A pinworm infection is treated with medicine that kills the pinworms inside your child's intestines. This medicine stops the pinworms from laying eggs. Other family members may also be given this medicine even if they do not have symptoms. Medicated creams may also be given to treat redness, pain, and swelling of your child's anus.

How can the spread of a pinworm infection be prevented?

  • Change and wash your child's clothes, underpants, and bed sheets daily. Do not shake the clothes or bedding before washing, because this may spread the eggs.
  • Give your child a bath after he or she wakes up every morning. Use a clean towel or washcloth every time. Wash your child's anus with soap and water.
  • Keep your child's nails short and clean.
  • Wash your hands after you change your child's diapers or help him or her in the bathroom. Have your child wash his or her hands before he or she holds or eats food.
  • Tell others to wash their hands before and after they take care of your child.

When should I seek immediate care?

  • Your child is not gaining weight and feels weak.
  • Your child has blood in his or her bowel movements.
  • Your child has severe abdominal pain.

When should I contact my child's healthcare provider?

  • Your child has a decreased appetite.
  • Your child has a fever.
  • Your child has diarrhea.
  • Your child has trouble sleeping.
  • Your child's anus becomes red and painful.
  • You have questions or concerns about your child's condition or care.

Care Agreement

You have the right to help plan your child's care. Learn about your child's health condition and how it may be treated. Discuss treatment options with your child's healthcare providers to decide what care you want for your child. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Further information

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