Pinworm infection is the most common type of intestinal worm infection in the United States. Pinworms are thin and white, measuring about 1/4 to 1/2 inch (about 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. Most people infected with pinworms have no symptoms, but some people experience anal itching and restless sleep.
Pinworm infection occurs most often in school-age children, and the microscopic eggs are easily spread from child to child. Treatment involves oral drugs that kill the pinworms and thorough washing of bedclothes, bed linens and underwear. For best results, the entire family should be treated.
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
A pinworm infection occurs when you accidentally swallow pinworm eggs. The microscopic eggs can be carried to your mouth by contaminated food, drink or your fingers. Once swallowed, the eggs hatch in the intestines and mature into adult worms within a few weeks.
Female pinworms crawl to the anal area to lay their eggs, which often results in anal itching. When you scratch the itchy area, the eggs cling to your fingers and get under the fingernails. The eggs then get transferred to other surfaces, such as toys or bedclothes. The eggs can also be transferred from contaminated fingers to food, liquids, bed linens, clothes 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 then take the tape to your appointment so the doctor can look for pinworms or eggs under a microscope.
Preparing a list of questions can help you make the most of your time with your doctor. For pinworm infection, some basic questions to ask include:
What to expect from your doctor
What you can do in the meantime
Tests and diagnosis
Your doctor can confirm the presence of pinworms by identifying the worms or eggs.
To help your doctor make a diagnosis, you can perform the tape test. As soon as the person you suspect has pinworms wakes up and before he or she uses the toilet, washes or gets dressed, press the adhesive side of a piece of transparent tape to the skin around the anus. The eggs stick to the tape.
For best results, perform the tape test three days in a row, and then take the tapes to your doctor. Your doctor can look at the tape under a microscope to see if there are any pinworm eggs.
Treatments and drugs
Mild pinworm infection, or an infection with no symptoms, may not 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 prescription anti-parasite medications for pinworms are:
You may have mild gastrointestinal side effects during the course of treatment, and you often need to take at least two doses to get rid of the pinworms completely.
Methods to help prevent the spread of pinworm eggs or to prevent reinfection include:
Last Updated: 2012-06-09
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