What are pinworms?

Q: I keep hearing about pinworms: How will we know if our kid gets them?

A: Many aspects of pinworms — how to find them and how they’re spread — are very unpleasant. Fortunately, pinworms usually aren’t a serious health issue. 

These creatures are small, thin worms that live in the intestinal tract. When an adult worm is ready to lay eggs, she migrates out to the skin around the anal opening and deposits the eggs. This usually happens at night. The presence of the adult worm and/or eggs can be very irritating to skin, so a child will scratch at the area, typically during sleep. If the child then puts a hand in his mouth, the infection will continue until the cycle is broken. 

Other family members can become infected if the child touches food products shared by the family. Sheets, blankets and bed clothing can also transmit the infection to other family members who handle infected items and don’t immediately wash their hands. Multiple family members can be infected, even though may not present any symptoms.

Diagnosis can be made in a number of ways. The typical way is when a parent looks at the perianal skin at night — typically using a flashlight — and sees thin, thread-like worms on the surface of the skin.

A more formal way is to do a pinworm paddle test. The small, adhesive-backed pinworm paddle is pressed to the perianal skin, where it will pick up the eggs if they’re present. The paddle is then placed on a glass slide and viewed under a microscope. If eggs are present, a clinician can see them with a microscope. This test is more likely to show the eggs if done at night or first thing in the morning.

Treatment is usually pretty simple, but actually getting rid of the infection from a household can be challenging. Medication will be recommended, often for all family members. It’s important to do everything you can to make sure sheets, blankets and any other pieces of bed clothing are well washed.

As always, if you have any questions about these topics, please talk with your child’s health-care professional.


Dr. Peter Dehnel is a board-certified pediatrician and medical director with Blue Cross Blue Shield of Minnesota. Send questions to drdehnel@mnparent.com. This column is intended to provide general information only and not medical advice. Contact your health care provider with questions about your child.