Pinworms are tiny white parasites that infest the intestines, mainly of children. They move to the anal area to lay their eggs, causing rectal itching, a sign that worms are present. Where a child scratches, eggs lodge under his fingernails and are passed on to others in the family by way of food, utensils, sheets, and towels.
If a child complains of itching or often scratches the anal area or if worms can be seen there or in bowel movements, call your doctor for advice and for a prescription. No over-the-counter remedy is effective.
To avoid reinfestation, snake sure that bed sheets, towels, and underwear are changed often and washed in very hot water. Have everyone in the household keep their fingernails clipped and wash their hands well before eating, before handling food, after going to the toilet, and after handling pets. Clean toilet seats daily.