Pinworms are common parasites that live in the intestine.
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A small white worm called Enterobius vermicularis causes pinworm infection. A separate species also causing infection (E. gregorii) has been reported in England.
Pinworms are visible to the naked eye. They are about the size of a staple, yellow-white in color, and look like a fine piece of thread, which moves actively.
Pinworms are spread by accidentally eating the eggs of the worm, which can be found on infected clothing, bedding, toys, or in the stool of an infected person.
Pinworms are most active at night, 2 to 3 hours after bedtime. The female worm comes out through the anus and deposits eggs in the perineal area. This area is between the anus and genitals.
Last reviewedJune 2014by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.