Boy sleeping in bed

The pinworm is a common intestinal parasite that lives in the digestive system of humans. Pinworms or, medically, enterobiasis is spread through human to human interaction. Most often, a person will contract pinworms by swallowing the parasites’ eggs. Adult pinworms are white in colour and very small, only 0.5 inches or 12.7 mm long. Their eggs are even smaller, too small for the naked eye, and only visible under a microscope. Pinworms are easily transferable – it has nothing to do with being unclean. The best defence against pinworms are to wash your hands regularly, keep your fingernails short, and to bathe and change your underwear, bedding and clothes regularly.


Pinworms are contracted through the ingestion of the parasites’ eggs. A mature pinworm will deposit its eggs near the anus region. Once deposited, they are easily transmitted and will stick to fingers, fingernails, hands, clothing, bed sheets – anywhere they can cause contamination. For up to three weeks, eggs can survive on a variety of surfaces. For this reason, pinworms spread very quickly and easily amongst areas where people live. For instance: family houses, day care centres and schools. Most commonly, eggs are ingested through swallowing. This can occur through fingernail biting, eating with contaminated fingers or even by breathing near bed fabric. They can also be contracted through anal insertion. The eggs will turn into pinworms in your small intestine and make their way through your digestive system. Once mature, it will lay eggs around the skin of the anus, causing itching. Once an outbreak of pinworms occur, it is difficult to control.


In some cases, there are no symptoms of a pinworm contamination. The worm will live out its life and leave the body through fecal waste. However, the most common symptom is itching or discomfort around the anus. Pinworms are relatively safe. They do not carry disease and don’t usually cause any serious health problems. However, they can cause a skin irritation and even infection around the anus through scratching. Symptoms won’t occur until 1-2 months after contraction. In some cases, irritation around the anus can become so severe that itching can lead to loss of sleep, appetite, and has be known to cause anxiety. Treatment can prevent symptoms from getting too severe.


There is over the counter medicine available to treat a pinworm contamination. There is also medicine available to treat the itching and irritating symptoms of pinworms. Consult your doctor about which medication is right for you. Medicine for pinworm contamination will only kill the mature worms and not the eggs, so two doses spread over a few weeks or a month may be needed. Because infection is so easily transferred, it is important to be regularly cleaning bed sheets and clothing, while washing hands regularly and keeping fingernails short. Treatment of all household members may be recommended if someone in the home is pregnant, breast-feeding or under 2 years old. Medication can be dangerous for these people and treatment of all household members will lower the chances of contamination.