DefinitionPinworms are small worms that infect the intestines.Alternative NamesEnterobiasis; Oxyuriasis; Threadworm; Seatworm; Enterobius vermicularis; E vermicularis; Helminthic infectionCauses, incidence, and risk factorsPinworms are the most common worm infection in the United States. They are most common in school-age children.Pinworm eggs are spread directly from person to person. They can also be spread by touching bedding, food, or other items contaminated with the eggs.Typically, children are infected by unknowingly touching pinworm eggs and putting their fingers in their mouths. The eggs are swallowed, and eventually hatch in the small intestine. The worms mature in the colon.Female worms then move to the child's anal area, especially at night, and deposit more eggs. This may caus