Under the microscope: Threadworms

Threadworms: Under the microscope | Prevention, symptoms and causes of threadworms

Average rating:

Each week we look more closely at the most common health conditions.

This week, we're focusing on threadworms.

What are threadworms?

Threadworms are very small, white worms between 2-13mm long and they look a lot like white thread, which is why they're called threadworms. They are also known as pinworms. Their eggs cannot be seen by the naked eye.

How do you get threadworms?

Threadworms are passed on by:

Bad hygiene, i.e. not washing your hands after going to the toilet
Coming in to contact with soil, dog and cat faeces and skin and objects contaminated with the worm's eggs. Dirty fingers or objects are put in the mouth and the eggs grow into worms in the intestines.

Who is affected by threadworms?

Threadworm is common in children because they pass on infection easily through play. But even after medication the worms can survive on bedding, clothing and objects, so good hygiene is really important.

How do I know if I have threadworms?

The most common symptom is an itchy bum. The worms lay their eggs at night when you're in bed and your body is warm. You scratch your bottom, often when you're asleep so you might not realise you are doing it, then put your fingers around or in your mouth or on an object such as a toothbrush and so the infection is spread.
Sometimes you only know you have them when you see the worms in the loo after you have been to the toilet.

Can I check my child for threadworms?

Yes. While your child is asleep, part their bum cheeks and use a torch to look for worms. Sometimes you may see one or two coming out of the anus, don't panic! At least it has confirmed the problem and now you can sort it out.

How do I get rid of threadworms?

You can get tablets from the pharmacist or you can see your GP who can prescribe some medication. This will kill the worms in the gut. The whole family will have to take the medication to make sure everyone is clear and the infection is not spread.

Your GP might ask you to do a Sellotape test. This involves pressing a bit of sticky tape to the anus, folding it up and sending off to a pathology lab. The tape will be looked at under a microscope to see if there are any worm eggs on it.

Your doctor can also refer you for a blood test if he or she suspects that you might have worms.

How can I prevent threadworm infection spreading?

You have to look out for it. Worms can survive for up to two weeks on bedding, toys and other objects. Everyone in the household, whether infected or not, should take these precautions for at least two weeks:

Wear close fitting underwear at night and change every morning. This is so you don't touch your skin if you scratch while you sleep.
If your child is very fidgety they might also benefit from wearing cotton gloves at night as well - and keep their nails short.
Always wear plain cotton underwear.
Wash bed linen, clothing, cuddly toys and towels on a high temperature setting.
Thoroughly vacuum the whole home and wipe everything down (including toys) with an anti-bacterial wipe, lotion or spray. Throw out the cloth after you've used it.
Vacuum mattresses and don't forget around and under the bed too.
Every morning, as soon as you get up, have a bath or shower and wash around the bottom and anus to get rid of any eggs laid overnight.
Wash your hands thoroughly when you get out of bed, after you go to the loo, after changing nappies and before and after preparing food. Use a nailbrush to clean under the nails too.
Don't bite your nails and try to stop your kids from sucking their fingers and biting their nails.
Avoid sharing towels.
Thoroughly clean toothbrushes and don't share them. Keep them stored in a cupboard and rinse before use.

What if I get threadworms when I'm pregnant?

If you're in your first trimester, then you shouldn't take medication. Hygiene is usually enough to get rid of them on their own - carry out prevention methods above for 6 weeks, which should break the cycle of re-infection.

If you are in the second or third trimester or you think you need medication, then go and see your doctor and he or she will advise you on the correct treatment.