Health Topics for Infectious Diseases

Department of Internal Medicine: Infectious Diseases

Department of Internal Medicine: Travel Medicine

Pinworms

Pinworms are small curved worms that live as parasites on horses, rabbits, and other mammals. Dogs and cats do not carry pinworms. One type infests the human intestines and rectum. These pinworms are also called "seatworms" or "threadworms." They most often occur in children between the ages of 5 and 14. A pinworm is white, very thin, and about one-quarter inch long. Pinworms are not dangerous but can be irritating and lead to skin infections due to scratching.

The female pinworm lives in the intestine and crawls to the opening of the rectum at night to lay her eggs. The sticky coating that attaches the eggs to the skin is irritating and causes itching. The young pinworms are transferred to the hands when the child scratches around the rectum. The most common symptoms are itching around the rectum and restless sleep. However, some people never have symptoms.

Pinworm eggs are very small and can be breathed in from the air or can be swallowed when a child puts dirty hands in their mouth. Pinworms may also be spread from objects such as toys or clothing. Pinworm eggs can live outside the body for up to 2 weeks in warm, moist conditions.

Pinworms can be treated with prescription or over-the-counter medication that are taken in 2 doses, 2 weeks apart. Because pinworm eggs are so small, they can be spread easily from person to person in the same household. If one person in the home has pinworms, others may be infected. If you suspect that your child or members of your household have pinworms, contact your healthcare provider to discuss treatment.

Your provider may ask you to use a home tape test for pinworms. Using a clear adhesive tape (such as scotch tape), apply the sticky side to both sides of the rectum. Do this in the morning, as soon as your child wakes up, before bathing or toileting. The pinworm eggs stick to the tape and can be identified under a microscope.

To reduce the chance of spreading pinworm infection, follow these suggestions:

• machine wash all clothing and bedding in warm water and dry in a heated dryer to kill any eggs
• vacuum or wet mop the entire bedroom and bathroom once a week to remove any eggs that may be scattered on the floor
• scrub hands and fingernails thoroughly before each meal and after each use of the toilet for at least 1 minute
• bathe or shower every day in the morning and
• do not fan the bedding of an infected person, which can release the eggs into the air

Contact your healthcare provider if symptoms worsen or do not improve.

Last Reviewed 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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