Information on Pinworms

  • Pinworms, small worms that infect the intestine, are the most common intestinal worm in the U.S.  They are most frequently seen in school-age children between 5 and 10 years old.  Pinworms spread easily from person to person by direct contact or from coming in contact with contaminated food or drink.  Pinworms enter the body through the mouth usually by touching something contaminated with pinworm eggs and then touching the mouth.  The eggs are swallowed and passed through the digestive system.  In the small intestine, they hatch and grow into baby worms.  They then move into the large intestine where they mature into adults.   After a few weeks, the female worms move toward the anal area where they come out at night and deposit eggs in the folds of skin around the anus.  The eggs irritate the skin and may cause intense itching, especially at night, which can interrupt sleep.  By scratching the area, the eggs are transferred to the skin under the fingernails and then transferred to others directly or by contaminating common items.  The whole process from ingestion of the eggs till the mature worms deposit eggs takes between 1 to 2 months.   

    Symptoms of pinworm infection:

    • Itching of the anal or vaginal area
    • Difficulty sleeping due to intense itching
    • Irritated or infected skin around the anus from scratching
    • Observation of adult worms in the toilet after going to the bathroom
    • Observation of worms on underwear or pajamas
    • Intermittent abdominal pain and nausea
    • Some people have no symptoms

    Pinworms can be detected in the anal area, especially at night when the worms lay their eggs.  If you suspect your child has pinworms, you can do a tape test as the eggs can be collected with cellophane tape.  In the morning, before bathing or using the toilet, place a piece of clear cellophane tape against the skin around the anus and remove it.  Take the tape to your physician.  By using a microscope, the doctor can detect the pinworm eggs and recommend treatment.


    • Pinworm infection is easily treated with an anti-parasite medication.
    • The medication will kill the worms, but it won’t kill the eggs.
    • A second treatment is often recommended after 2 weeks – this will kill any newly hatched worms.
    • The whole family should be treated since pinworms are easily passed to other family members.

    To control the eggs:

    • Shower in the morning to remove any eggs that are laid overnight. Showering is preferable to bathing as bath water may become contaminated with eggs.
    • Avoid scratching the anal area
    • Keep fingernails short and clean – makes it more difficult for eggs to collect under the fingernails
    • Wash hands with warm soapy water before meals and after using the toilet
    • To help kill pinworm eggs, wash all bed linens and pajamas twice a week in hot water.
    • Clean toilet seats every day


    • Wash hands with warm soapy water often, but especially after using the bathroom, before preparing food, and before eating.
    • Wash bed linens and underwear frequently.