Pinworm infestations

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Learn about the symptoms, treatment and prevention of pinworm infestations. Pinworms are infectious and can be spread through ingestion.

Key points

  • Pinworms are white, thin, wiggly worms that measure about one-quarter of an inch in length and cause itching, irritation and discomfort.
  • If your child has pinworms, their doctor can prescribe special medication to treat the problem.
  • To prevent pinworms, wash your child's hands and fingernails thoroughly, vacuum or wet mop your child's room once per week, wash your child's clothing and bedding in warm water.

Pinworms are white, thin, wiggly worms that measure about one-quarter of an inch in length. If your child has pinworms, you will be able to see the little worms in the area around the anus, known as the perianal area. They are easiest to see at night or in the early morning. You might also see the pinworms on the surface of your child’s bowel movement, or at the entrance to your daughter’s vagina.

Although pinworms do not cause any serious health problems, they are a source of great discomfort, itching, and irritation in the perianal area. Pinworms are infectious, and can spread from child to child. A child can develop a pinworm infestation if they swallow pinworm eggs. The worm usually develops about three to four weeks after the egg has been swallowed.

Checking for pinworms

If your child is very itchy in their perianal area, they may have pinworms. However, an itchy anus could simply be caused by overly vigorous washing of the area with soap. You will need to check your child’s perianal area to make sure the pinworms are indeed present. Use a flashlight to search for a little, threadlike, wiggly worm. Try doing this a few hours after your child has gone to bed and again in the morning for a couple of nights.

If you do not see a pinworm, do the following so that your doctor can check for pinworm eggs:

  • Obtain a couple of glass slides from the doctor’s office.
  • In the morning, right after your child wakes up, stick a piece of clear Scotch tape to the skin on both sides of the anus.
  • Stick the piece of tape to a slide.
  • Repeat these steps the following day with a second slide.
  • Bring both slides to your doctor’s office so they can have it examined under a microscope.

Treating pinworms

If your child has pinworms, their doctor can prescribe special medication to treat the problem. Sometimes the entire family may need to be treated for pinworms, depending on if they have had very close contact with your child or if they are showing symptoms. The doctor will decide how high the risk is that other family members may develop pinworms.

Preventing pinworms

Your child can get pinworms no matter how clean you keep your house. However, you can try the following precautions to reduce the chances of getting a pinworm infection:

  • Wash your child’s hands and fingernails thoroughly before meals and after using the toilet.
  • Keep your child’s fingernails clipped short to keep the eggs from collecting under the nails. Discourage your child from sucking their thumb or biting their nails.
  • Vacuum or wet mop their room once per week because if there are eggs on the floor, they will remain contagious for one to two weeks.
  • Wash your child’s clothing and bedding in warm water to kill any remaining eggs.
Last updated: October 18th 2009