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What are pinworms? — Pinworms are small worms that can live in people's intestines (figure 1). They are the most common cause of worm infections in the US. Pinworm infections usually affect school-age children.
People who have pinworms can have intense itching around their anus. That's because the female worms lay their eggs in the folds of skin around the anus.
People catch pinworms when they swallow pinworm eggs. This can happen when someone with a pinworm infection scratches their anus, touches things that other people might touch, and leaves eggs behind. Then, when someone touches the eggs and touches their mouth, they can swallow the eggs without knowing.
What are the symptoms of pinworms? — Many people with pinworms don't have any symptoms. When people do have symptoms, the most common symptom is itching around the anus. The itching happens most often at night and can cause trouble sleeping. Some people with a severe case of pinworms might also have belly pain, nausea, and vomiting.
Should I see a doctor or nurse? — Yes. If you have severe itching around the anus, especially at night, you should see your doctor or nurse.
Is there a test for pinworms? — Yes. After learning about your symptoms, your doctor or nurse will have you do a "scotch tape" test. This test involves taking a piece of scotch tape and pressing it on the skin around your anus. If you have pinworms, the eggs will stick to the tape. The doctor or nurse will look at the tape under a microscope to see if there are pinworm eggs on the tape. (You can't see the eggs by just looking at the tape.) It is best to apply the tape at night or first thing in the morning before you bathe.
How are pinworms treated? — Pinworms are treated with medicine. People being treated usually take a pill when they first find out they have pinworms. Then, they take another pill 2 weeks later.
If you have pinworms, your doctor or nurse will probably want all the people who live with you to take the medicine. This is because pinworms spread easily between people in the same home.
Even after you are treated, the pinworms might still come back.
Is there anything else I should do? — Yes. If you or anyone in your family has pinworms, you all should:
Keep your fingernails clipped short.
Wash your hands often with soap and water.
Take a shower or bath every day. (In the morning is best.)
Wash your clothes, towels, and bed linens often.
Try not to scratch around your anus or between your legs.
See your doctor or nurse if you start having itching around your anus again.
All topics are updated as new evidence becomes available and our peer review process is complete.
This topic retrieved from UpToDate on: Mar 30, 2020.
Topic 83446 Version 4.0
Release: 28.2.2 - C28.105
© 2020 UpToDate, Inc. and/or its affiliates. All rights reserved.

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