Pinworms

Pinworms

What are pinworms?

Pinworms are small, white, threadlike roundworms (about ½ inch in diameter) that live in the large intestine and come out to lay eggs around 9-10 PM at night. There are very few other worms that inhabit the human body that have these 3 characteristics: small, white and symptomatic at night.
Pinworm infections are annoying but not serious. They cause no serious complications.

What are the symptoms?

Intense itchiness around the anus or the vagina. This occurs when the worms exit the body to lay worms. Up to 10,000 eggs can be laid at any one time. The itchiness is caused by the local reaction of the body to the eggs.

How is pinworm contracted?

Pinworm eggs must be ingested and then they make their way through the GI tract over a 1-2 month period before exiting at the anus.
Pinworm is spread directly or indirectly by sharing toys, clothing, toilet seats or baths.
Pinworm eggs are microscopic and can float in the air for up to 2 weeks.

How long is a person contagious?

The adult pinworms die shortly after laying their eggs. The eggs are contagious for 2-3 weeks and the disease spreads when picked up by children who wipe their anus and then touch a food or surface that is touched by another person.

How is pinworm diagnosed?

For children in diapers, the diagnosis is easy because you can see the white worms mixed into the stool.
For toilet trained children, it is more complicated to make a diagnosis. The classic test is the scotch tape test where clean scotch tape is placed over the anus and removed in the morning, brought to the doctor and placed under a microscope. This is cumbersome and difficult to accomplish for almost any parent and we do not recommend this approach.
Most pediatric providers will treat based on severe itchiness only at night.

What is the treatment?

There are two effective treatments:
1. Vermox or mebendazole is given as a pill that is by prescription only. Our general rule is to treat just the patient and no other family members if there is just one case. If more than one child is symptomatic, we will usually treat everyone (except pregnant women). We usually treat a second time in 2 weeks. This is one dose for all over age 2 years. It is a tablet which has to be crushed and placed in food for children who cannot swallow.
2. Pyrantal Pamoate is an over the counter medication that is given based on body weight. The two brand names currently available are Pin-X and Reese’s Pinworm Medicine. These are also not approved for children under 2 years and should be repeated in 2 weeks.
Treatment is almost 100% effective. Most new cases are recurrences that come from children reinfecting themselves with eggs that are floating in their environment.

What should be done in addition to treatment?

Avoid scratching the buttocks or anus
Wear tight underwear both day and night and change them daily
Wash fingers especially before eating. Adults with pinworm should not be food preparers.
Cut nails short
Clean the bedroom floor by damp mopping, Swiffering or vacuuming. Avoid sweeping as that may spread the eggs.
Wash all pajamas in a hot cycle
Use a disinfectant for the toilet seat
Avoid bathing children together

What looks like pinworm?

Standard diaper rash can have the same redness but is usually not itchy
Eczema typically does not appear around the anus but also can be itchy and scaly
Strep peri-anal cellulitis is a “ring around the anus” that is usually painful and not itchy