Pinworm infection is the most common type of intestinal worm infection in the United States. Pinworms are thin and white, measuring about 1/4 inch to 1/2 inch (5 to 13 millimeters) in length.
While the infected person sleeps, female pinworms lay thousands of eggs in the folds of skin surrounding the anus. While most people infected with pinworms have no symptoms, some people experience anal itching and restless sleep.
Pinworm infection occurs most frequently in school-age children, and the microscopic eggs are easily spread from child to child — especially if children scratch their bottoms or neglect to wash their hands after using the bathroom or before eating.
Treatment involves oral drugs that kill the pinworms. For best results, the entire family should be treated at the same time.
An adult pinworm generally is 1/4 inch to 1/2 inch (5 to 13 millimeters) in length. The most common symptom of infection is anal itching, particularly at night, as worms migrate to the host's anal ...
Symptoms of pinworm infection may include:
Some people with pinworms have no symptoms.
When to see a doctor
You acquire a pinworm infection by accidentally swallowing pinworm eggs. The microscopic eggs can be carried to your mouth by contaminated food, drink or fingers. Once swallowed, the eggs hatch in the intestines and mature into adult worms within a few weeks.
Female worms crawl outside the anus to lay their eggs, which often results in anal itching. When a person scratches the itchy area, the eggs cling to fingers and are then transferred to other surfaces, such as toys or bedclothes. The eggs can also be transferred from contaminated fingers to food, liquids or other people.
Pinworm eggs can survive for two to three weeks on surfaces. You can become infected with pinworms if you consume contaminated food or drink, or if you touch a contaminated surface and then touch your mouth.
Risk factors for pinworm infection include:
Typical pinworm infections don't cause serious problems. In rare circumstances, heavy infestations may cause:
Preparing for your appointment
What you can do
You may also want use clear cellophane tape to take samples from the anal area as soon as the infected person wakes up — before any trips to the bathroom. Your doctor can look at the tape under a microscope to see if there are any pinworm eggs.
What to expect from your doctor
Treatments and drugs
Mild pinworm infection, or an infection with no symptoms, may never need treatment. If treatment is needed, your doctor may prescribe medication to all members of your household to prevent infection and reinfection. The most common anti-parasite medications for pinworms are:
You may have mild gastrointestinal side effects during the course of treatment, and you may need to take multiple doses to get rid of the pinworms completely.
Methods to help prevent the spread of pinworm eggs include:
Last Updated: 2010-02-23
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