Pinworms (threadworms) are the most common worm infection in the US. They’re especially common in children aged 5 to 10 and spread easily within families. They’re harmless in most cases and easy to treat, but reinfection is common unless everyone follows a few hygiene steps.
Symptoms
- An itchy bottom, especially at night, when female worms lay eggs around the anus.
- Disturbed sleep, restlessness and irritability.
- In girls, itching around the vagina.
- Small white thread-like worms, about the length of a staple, may be seen around the bottom or in stools.
Many people have no symptoms at all.
How it spreads
Scratching transfers tiny eggs to fingers and under nails, and from there to the mouth, food, toys, bedding and surfaces. Eggs can survive for up to 2 to 3 weeks indoors.
The tape test
A doctor may ask you to press clear sticky tape against the skin around the anus first thing in the morning, before washing or using the toilet, on 3 mornings in a row. The tape is then checked for eggs.
Over-the-counter treatment
- Pyrantel pamoate (sold as Pin-X and Reese’s Pinworm Medicine) is available without a prescription for adults and children aged 2 and over.
- It’s taken as a single dose based on body weight. Follow the dosing chart on the pack.
- A second dose 2 weeks later is often recommended, because the first dose doesn’t kill eggs.
- Ask a doctor before using it in children under 2 or weighing under 25 lb, in pregnancy or while breastfeeding, or if you have liver disease.
Prescription options include mebendazole and albendazole.
Treat the whole household
Because eggs spread so easily, doctors usually advise treating everyone in the home at the same time, even those without symptoms.
Hygiene to stop reinfection
- Wash hands with soap after using the toilet, before eating and after changing nappies.
- Keep fingernails short and discourage nail biting and thumb sucking.
- Shower or bathe each morning to remove eggs laid overnight.
- Change underwear and pyjamas daily, and wash bedding and towels in hot water. Don’t shake them out first.
- Wipe down toilet seats, door handles and toys.
Keep up these steps for at least 2 weeks after treatment.
See a doctor if
Symptoms continue after two doses, you’re pregnant, a child under 2 is affected, or there’s stomach pain, weight loss or blood in the stools.
More in our Lice and Parasites guide: all our articles on this topic in one place.
This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Always read the label before using any medicine.
