Pinworm infection is a common parasitic infection caused by the small, white, thread-like pinworms (Enterobius vermicularis) that live in the large intestine of humans. The infection is most commonly found in children and can be easily spread from person to person.

Symptoms of pinworm infection may include anal itching, particularly at night, as the female pinworms lay their eggs around the anus. Other symptoms may include irritability, abdominal pain, and loss of appetite.

Diagnosis of pinworm infection is usually made by examining the area around the anus for pinworm eggs, which can be seen with the help of a flashlight. A doctor may also order a tape test, in which a piece of tape is applied to the skin around the anus and then examined under a microscope for the presence of pinworm eggs.

Treatment for pinworm infection usually involves a medication called mebendazole or albendazole, which is taken orally to kill the pinworms. In addition, good hygiene practices such as frequent hand washing and washing clothes, bedding, and towels in hot water can help prevent the spread of infection.

Prevention of pinworm infection involves practicing good hygiene, including frequent hand washing, regular bathing, and washing clothes and bedding in hot water. It is also important to avoid touching the mouth or nose after touching objects that may be contaminated with pinworm eggs and to avoid scratching the anal area. If you suspect you or your child has a pinworm infection, it is important to seek medical attention to receive appropriate treatment and prevent the spread of infection to others.

Accidentally swallowing or breathing in pinworm eggs causes a pinworm infection. The tiny (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 move 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 your fingernails. The eggs then get transferred to other surfaces, such as toys, bedding or toilet seats. The eggs can also be transferred from contaminated fingers to food, liquids, clothes or other people.

Pinworm eggs can survive for two to three weeks on surfaces.

Pinworm eggs can cling to surfaces, including toys, faucets, bedding and toilet seats, for two weeks. So besides regular cleaning of surfaces, methods to help prevent the spread of pinworm eggs or to prevent reinfection include:

• Wash in the morning. Because pinworms lay their eggs at night, washing the anal area in the morning can help reduce the number of pinworm eggs on your body. Showering may help avoid possible re-contamination in bath water.
• Change underwear and bedding daily. This helps remove eggs.
• Launder in hot water. Wash bedsheets, pajamas, underwear, washcloths and towels in hot water to help kill pinworm eggs. Dry on high heat.
• Don't scratch. Avoid scratching the anal area. Trim your child's fingernails so there's less space for eggs to collect. Suggest that your child avoid biting his or her nails.
• Wash your hands. To reduce your risk of getting or spreading an infection, wash your hands well after using the toilet or changing a diaper and before eating.

To treat pinworm infection, your doctor may recommend over-the-counter pyrantel pamoate or prescribe medication to all members of your household to prevent infection and reinfection.

The most common prescription anti-parasite medications for pinworms are:

• Mebendazole
• Albendazole (Albenza)

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.