Pinworms Patient Information Fact Sheet

What are pinworms?
Pinworms are the most common parasitic worms found in temperate countries and usually affect children under 18 years old. The worms can be spread by children sucking objects or eating food that is contaminated by pinworm eggs. Pinworms are parasites that live in the intestines, but at night the females come out of the rectum to lay their eggs on the skin around the anus. These eggs can cause itching and sometimes inflammation as a result of the person scratching the area constantly. Eggs on the fingers or under the nails can then be transferred to the mouth of the sufferer or other persons, maintaining or spreading the infection. The eggs may also survive in dust for up to 2 weeks and may be passed on if the dust is inhaled. If a child has pinworms it is usual for the whole family to be treated as other members may also be infested even if they do not have any symptoms.

How are pinworms diagnosed?
The tiny worms, like threads of cotton, may be seen moving on feces. You may be asked to apply a piece of clear adhesive tape to the skin near the anus. Pinworm eggs will stick to it, and can be seen under the microscope.

How are pinworms treated?
Pinworms are usually treated with mebendazole. They can also be treated with pyrantel pamoate (Pin-X), available over-the-counter, and  albendazole (Albenza), which requires a prescription. Patients are often advised to repeat the dose after 14 days to help prevent re-infection.

Self-help measures

  • Ensure children always wash their hands after going to the bathroom and before meals
  • Shower daily to remove any eggs from the anal area, change underwear daily and bedding regularly
  • Keep fingernails short, ideally children should wear cotton gloves to bed
  • Keep your house as dust-free as possible
  • Treat the whole family on the same day to avoid reinfection

Further Information
Centers for Disease Control and Prevention: http://www.cdc.gov/parasites/pinworm/

Last Reviewed: May 2013