Symptoms and Signs of Pinworm Infection

Medical Author:
Medically Reviewed on 9/7/2021

Doctor's Notes on Pinworm Infection

A pinworm is a helminth, subgroup nematode (Enterobius vermicularis), that causes enterobiasis (pinworm infection), a parasitic worm infestation also termed a seatworm or threadworm. The term oxyuriasis means infestation with or disease caused by pinworms. This disease usually occurs in a child and may produce the following signs and symptoms although some children may have no symptoms or signs:

  • Intense anal itching (due to movement of adult worms)
  • Prickly pain in anal area (due to adult female worms depositing eggs)
  • Rash in anal area
  • Visualization of pinworms in stools and/or anal area (thin whitish worms ranging from 2-3 mm long)
  • Restless sleep
  • Less frequent symptoms include abdominal discomfort, loss of appetite, irritability, and vaginal itching

The cause of pinworm infection is Enterobius vermicularis. The pinworms pass easily from child to child (or even to some adults) with contaminated fingers, food, drink, and from some contaminated surfaces.

Treatments of pinworm infections may include prescription or over-the-counter medications:

Note that the drugs only kill adult pinworms. Consequently, a second dose of medication needs to be given 2 weeks after the first dose to kill any new adult worms that hatched from eggs. In addition, if other family members are infected, it is recommended that all family members be treated at the same time.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.