What every parent needs to know about pinworms

Pinworms are tiny white roundworms that enter the body through the mouth after you touch something that's contaminated with pinworm eggs, then touch your hands to your mouth. The worms make their way through the digestive system and lay their eggs in the rectum. This may seem like a scary scenario from one of the Alien movies, but it’s really quite common, particularly among school-aged children. 

According to the US Centers for Disease Control, around 50 percent of kids under 18 get them at some point. “It’s so easy to spread their eggs,” says Janice Heard, a Calgary-based paediatrician. “They’re in the sand, in our houses and on children.”

The thought of this is gross for sure, but it’s par for the course when you’ve got kids. Schools are a common place to find pinworm transmission. If you’re squeamish, steel yourself: Here’s all you need to know about pinworms and how to treat them.

The most common symptoms are itching and discomfort around the anus. Girls can experience vaginal discomfort and discharge too, as worms can get into the vagina as well. Disturbed sleep is also common, because pinworms tend to emerge in the dark. However: “Kids can be carrying them for a long time and not know,” says Heard. “Sometimes it’s seeing a worm after a bowel movement in a diapered child that alerts parents.” You may also spot the tiny worms crawling out of your kid’s bottom - they are about the size of a staple.

It may be startling to see the worms, but they only cause minor skin irritation. “Pinworms don’t cause harm to the body,” says Heard. “They don’t go into the liver or brain; they don’t cause disease.” Just like getting a cold or flu, pinworms don’t discriminate and can affect anyone – they have nothing to do with cleanliness. 

If you suspect your kid has pinworms, your doctor may ask you to test for them yourself by putting a piece of tape over your child’s anus. If eggs are present, they’ll stick to the tape. Take the tape in a sealed plastic bag to your paediatrician’s office, where it will be tested for the presence of pinworms, which can only be seen under a microscope. It’s a painless procedure, but don’t be surprised if your kid freaks out a bit. “It’s really fun to try to get your child to cooperate, because it’s weird to cover their anus with tape,” says Gowan. “Ellie said, ‘Ew, gross, Mom!’”

If the diagnosis is confirmed, it’s recommended that all family members who have symptoms be treated. Your doctor will either suggest an over-the-counter anti-parasitic medication or give you a prescription for one, plus may recommend a cream to reduce the itching. The first dose of medication is taken immediately and the second dose is taken two weeks later. Kids can still go to school while they’re being treated. 

In the two weeks between treatments, you’ll have to be diligent about hygiene. Each family member should bathe separately every morning. Wash bedding in hot water and detergent every three to seven days, and launder pajamas and hand towels every day. You’ll also want to clean toilet seats frequently, wash toys, wipe off surfaces in bedrooms and avoid shaking out linens and pajamas so you can keep the worms and eggs contained. Another hot tip from Heard: Flood your bedrooms with daylight. Pinworms hate the sun.

“There should be an improvement in symptoms after the first dose and a marked decrease in itching seven days after the second dose,” says Phil Emberly, director of practice, advancement and research for the Canadian Pharmacists Association. If symptoms persist or if your child has any abdominal pain that doesn’t go away, it’s best to report back to your doctor.

Kids easily pick up pinworms at school, daycare and other places where a lot of kids are present. When your child touches a toy or an object contaminated with pinworm eggs and then touches their face, these eggs can be accidentally ingested. Once swallowed, the eggs hatch and grow inside the intestines. Young children in oral stages of development are most at risk for developing pinworms in this way.

Children spread infections to other children through touch and ingestion of pinworm eggs, much like the previous example. Pinworms lay their eggs in the skin around the anus, which can make children itchy or irritated. Scratching and wiping this area can transmit the eggs to their fingers or under their fingernails. This makes it easy to spread the eggs to other children.

Kids who touch the pinworm eggs then inadvertently put their hands in their mouths or nose, which allow the eggs to hatch and grow inside the intestines.

It can be alarming when your child is diagnosed with a pinworm infection. Luckily, these infections rarely lead to serious complications or conditions, although some kids complain of a stomach ache or diarrhea if the worms have multiplied significantly.

Prompt anti-parasitic treatment usually ensures complete resolution of the pinworm infection. However, if left untreated, a few rare complications can occur. These include bacterial infections, UTIs, appendicitis and divertculitis.

This is a popular misconception. Pinworm infections are rarely spread through swimming pools, even though chlorination does not kill pinworm eggs. These eggs are microscopic, so even if some slough off while children are swimming, it is unlikely your child would swallow the eggs due to the large volume of water in the pool. It is much more likely for your child to become infected with pinworms at school, daycare or play dates.

Pinworms are the most common type of intestinal worm infection in the United States. These small organisms range from 1/4 to 1/2 an inch and are white in color. They live inside the large intestine or colon, but female pinworms emerge at night to lay eggs in the folds of skin surrounding the anus. The eggs can cause redness and itching, which is one of the first signs of a pinworm infection. While pinworms are considered parasites, they are relatively harmless and easy to treat.

It’s tough to avoid pinworms because they are so contagious, but fastidious handwashing can help keep them at bay. Cut kids’ nails short, especially in the camp and back-to-school seasons, when infections are apt to ramp up. Try to discourage thumb sucking and nail biting, as eggs tend to hide out under fingernails. But overall, don’t worry too much about pinworm infection, says Heard. “It’s likely most people have had them in their lives at some point, and this, too, shall pass.”

This story was originally published in 2018.