When your mom or dad tells you to wash your hands before a meal, you probably don't think they're dirty, right? But did you know that tiny worm eggs could be stuck under your fingernails?

It's gross to think about, but anybody can get pinworms. To learn how to stay worm-free, read on!

What Are Pinworms?

Pinworms are a type of little worm that commonly infects the intestines, often in kids. Many of the kids in your school have probably had pinworms at one time, and the worms are nothing to be afraid of.

Pinworms are really small — about as long as a staple. Their eggs get inside the body through the mouth after you touch something which is contaminated with pinworm eggs, then touch your hands to your mouth.

After getting in your mouth, the eggs pass through the digestive system. The eggs hatch in the small intestine, and the baby worms grow and move on to the large intestine. There, the pinworms grab onto the wall of the intestine. After a few weeks, the female pinworms move to the end of the large intestine, and they come out of the body at night to lay their eggs around the anus.

The amount of time that passes from when someone swallows the eggs until the worms lay new eggs is about 1 to 2 months.

How Do I Get Pinworms?

Pinworm eggs can end up on anything that someone who has pinworms touches: on a counter in the kitchen, in a bed, or on a desk at school. The eggs also can be on clothes, towels, or eating utensils. The eggs can live for about 2 weeks, and when you accidentally touch them and then put your fingers in your mouth, you can swallow the eggs without even knowing it.

Pinworms can also spread from one person to another. The worms do not come from pets, only people. And people who have pinworms are not dirty — kids can get pinworms no matter how often they take a bath or play in the mud.

Kids in school get pinworms easily because they spend a lot of time with other kids, who may have pinworms. They might touch something with pinworm eggs on it when they're playing with other kids and eat the eggs without even knowing it. The eggs are so light that a few may even end up in the air, where they could be swallowed when you breathe in. This is not a common way of getting pinworms, though.

If you already have pinworms, you could swallow more eggs if you scratch around your bottom and put your fingers in your mouth. Or a few of the eggs around your anus could hatch while they're on your skin, and the baby worms might crawl back inside your body and grow into adults.

How Do I Know If I Have Pinworms?

If you have pinworms, you might see the worms in the toilet after you go to the bathroom. They look like tiny pieces of white thread. You also might see them on your underwear when you wake up in the morning. But the pinworm eggs are too tiny to be seen without a microscope.

The itching from the pinworms might wake you up in the middle of the night and make you squirm a lot. So if you're itchy and sore on your backside, tell your mom or dad. And if you see worms in your underwear or in the toilet, you should tell a parent right away. You should know, though, that some people with pinworms don't have any symptoms at all.

What Will the Doctor Do?

If your parent thinks you have pinworms, she or he will take you to the doctor so you can get medicine to get rid of the worms.

To be sure that you have pinworms, the doctor may have your parent help you do an easy test at home. Your parent will place a small piece of tape on the skin around your anus at night or when you first get up in the morning, then take it off and bring it to the doctor. It doesn't hurt at all, and the doctor will look at the tape under a microscope to see if there are any eggs on it. He or she might also take some samples from under your fingernails to see if there are any eggs.

If you have pinworms, don't worry. They don't cause any harm (just itching!), and it won't take long to get rid of them. Your doctor will give you some medicine that you will take 2 times over 2 weeks to be sure the worms are gone. The doctor can also give you a cream to help stop the itching.

Because it's easy to pass pinworms on to other people, the doctor may want the other people in your house to take medicine, too. Your mom or dad will probably want to wash everyone's sheets and pajamas to get rid of any eggs that might still be around.

How Do I Keep Pinworms Away?

The best way to keep from getting pinworms is to wash your hands with warm, soapy water before you eat, after you play outside, and after you use the toilet. Try to keep your fingernails short and clean, and don't scratch around your bottom or bite your nails.

Because pinworm eggs can hang around in clothes, be sure to change your underwear every day and always put on a clean pair. Ask someone to wash your pajamas every few days, too.

With these simple steps, you can keep the worms away!

Reviewed by: Yamini Durani, MD
Date reviewed: May 2011