A common infestation with a small worm, ENTEROBIUS VERMICULARIS (also called pinworm), that lives in the intestines. Threadworms mostly affect children.
Female adult threadworms are white and about 1cm long (large enough to see). They lay eggs in the skin around the anus, and their movements cause itching in the anal area, usually at night. Eggs are transferred from the fingers to the mouth to cause reinfestation or are carried on blankets or toys to other children. Swallowed eggs hatch in the intestine and the worms reach maturity after a period of two to six weeks.
Adult worms can occasionally be seen in the buttocks or faeces. The worms and their eggs can be collected by applying a piece of sticky tape to the anal region. Treatment is with an anthelmintic drug, which often clears up the problem. Doctors advise that all members of a family to be treated at the same time.