The pinworm, or Enterobius vermicularis, is a small parasitic worm that lives inside the large intestine in humans. Measuring only 3-10 mm in length, it causes intense anal itching, especially at night.
Pinworms usually infest people attending overcrowded schools, living in large family groups or in unsanitary conditions, or those who eat undercooked food. Moreover, they are not necessarily a sign of poor personal hygiene. They are very often found in institutional settings such as dormitories, psychiatric hospitals and shelters. The pinworm symptoms are many.
The pinworm is the most common parasite among children in North America and it is estimated that one third of Canadian children have pinworms at some point in their lives. A few pinworm pictures can be found here .
