Pinworms: Treatment and Prevention

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Pinworms are small white worms about 1/2 inch long and as thin as a thread. They can sometimes be seen in and around the child's bottom (anus) and in bowel movements. These worms live in the intestine. The adult female worm crawls out of the infected person’s anus at night and lays her eggs in the surrounding skin. This causes itching and scratching. The worms can also move to the vagina of a female child and cause itching. 

Eggs can live for 2 to 3 weeks outside the body. They can be found in house dust, on toilet seats, bed linens and toys and in play areas in or outside the home. Although pinworms only grow in humans, the eggs can be carried in a pet’s fur. 

Pinworms are harmless but annoying. They spread easily to others.

How the Infection is Spread

When the child scratches, tiny eggs are picked up on the fingers. The eggs are left on any surface that is touched. They are then picked up again and swallowed when fingers, foods or anything that has eggs on it, are put in the mouth.   

How Pinworms Are Diagnosed

You have to see the eggs or worms to make the diagnosis.  The best way to do this is by doing a tape test.  In the morning, before your child goes to the bathroom or washes up, put the sticky side of a piece of clear tape around the anus.  Remove the tape and look for pinworms or their eggs.  You can also buy a tape test kit at the pharmacy.  If you do not find pinworms, do the tape test 2 more mornings in a row, to be sure.

How to Treat the Infectionwashing hands with soap

  • Your child’s doctor will prescribe a special medicine to treat pinworm infection.The dose is based on the person’s weight.Usually 2 doses of the medicine are ordered.The second dose starts 2 weeks after the first.
  • Read the label on the bottle of medicine to know how to give it.
  • Your child’s doctor will also treat other family members and close contacts with the same medicine, at the same time.

How to Prevent Reinfection or Spreading Pinworms to Otherscleaning the toilet

It is easy to be reinfected with pinworms or spread them to others.  During treatment and for 2 weeks after treatment is finished, do the following:

  • Hand washing is most important.Have your child and all family members wash their hands often.They should wash before meals or eating, after using the toilet and after scratching (Picture 1). This is a good habit to do at all times.
  • Keep your child's fingernails clean and cut as short as possible.
  • Teach your child to avoid touching his mouth or biting his fingernails.
  • Have your child shower or bathe every morning.
  • Do not let children bathe together or share items.
  • Clean the anus with soap and water after each bowel movement.Use clean washcloths or paper towels each time.
  • Scrub the toilet seat daily with disinfectant or soap and water (Picture 2).
  • Wipe down any toys that your child usually puts in his mouth or hard surfaces that he has touched with disinfectant or soap and water.
  • Change bed linens and put clean underwear and clothes on every day.Avoid shaking these things so that eggs are not put into the air.
  • Promptly wash used bed linen, all clothing, towels and washcloths in hot water with detergent.
  • Vacuum carpets and floors well.Wash the canister or change the vacuum cleaner’s bag after each use.Seal the bag before throwing it away.
  • Wash any raw vegetables or fruits thoroughly before eating.
  • Call your child's school or childcare center so that they can take extra steps to prevent the spread to others.Your child can return to school or childcare 24 hours after treatment.

When to Call Your Child’s Doctor

  • If you see pinworms
  • If anal itching lasts more than 1 week
  • If the skin around the anus becomes red or tender

Pinworms: Treatment and Prevention (PDF)

HH-I-56 10/78, Revised 3/19 Copyright 1978-2011, Nationwide Children’s Hospital