Threadworms (also known as pinworms) are an extremely common infection and many young children will be affected at least once if not more.


Threadworms cause itching around the anus (the opening we poo through) which can be extremely irritating but they can be treated with a combination of medication which can be bought over-the-counter and hygiene measures at home.

What's the main sign or symptom that your child has threadworms?


You also might see the tiny worms in your child's poo. They are called threadworms as that is what they look like: small pieces of white cotton thread.

They cause itching which can be around the anus and/or vagina. The itching is often worse at night and can lead to your child waking up at night, or being irritable/tired in the daytime. The skin around the anus can become irritated due to the itching.

More like this

What are threadworms exactly?

Threadworms are a form of parasitic infection that live in the intestines. They come out of the anus at night to lay their eggs.

How do you get threadworms? Are they contagious?

Threadworms are extremely contagious. The eggs are laid around your anus which is irritating, so you itch. The microscopic eggs then get stuck on your fingers and fingernails. This means that you can pass them onto any surface you touch, such as clothes, door handles, toys, kitchen surfaces, food and more.

When other people touch these infected surfaces, they can pick up the eggs – which they then swallow if they touch their mouth.The eggs can live for up to 2 weeks outside the human body.

Although your child does not need to stay home from school or nursery if they have threadworms, it is sensible to inform the nursery/school, so that other parents may look for the signs/symptoms in their children and treat them appropriately if needed.

How do you get rid of threadworms?

You can buy a medication containing mebendazole over the counter to treat threadworms. It comes as a liquid or as a chewable tablet.

Everyone living in your home needs to take the medication treatment, even if they do not have any symptoms.

If your child is under 2 or you are breastfeeding, please discuss the treatment with the pharmacist. If you are pregnant, you'll need to discuss treatment with your GP.

The medication only kills live threadworms, however. It doesn't kill any eggs, which can live for up to two weeks either in or outside the body. So, it is important to complete the following hygiene measures to avoid getting reinfected:

  • Wash your hands, including under fingernails, frequently an especially after going to the toilet/changing nappies and before eating.
  • Wear underwear at night for 2 weeks after taking the medication, to try to prevent getting eggs under your fingernails if you scratch in your sleep. The underwear should be changed in the morning, and hands and nails washed straightaway.
  • Have a bath or each morning.
  • Cut fingernails short.
  • Keep toothbrushes in the bathroom cabinet and rinse them before using them.
  • Wash all bedding, clothes worn at night, soft toys and towels at a high temperature to kill any eggs.
  • Damp dust, vacuum and clean all kitchen and bathroom surfaces to try to remove any eggs.
  • Don't share towels/flannels and don’t shake towels or bedding as this can spread eggs.

It is possible to take a second dose of the mebendazole, generally 2 weeks after the first, to try to treat any reinfection if symptoms don't resolve.

Can adults get threadworms?

Yes, anyone can get threadworms. This is why the whole household needs to be treated.

What if I’m pregnant and have threadworms?

Please discuss this with your doctor. Mebendazole can be used with medical advice but it is generally recommended to try to treat threadworms with hygiene measures in the first instance, especially in the first trimester.

What if my baby has threadworms?

Please discuss this with your pharmacist. They will able to recommend appropriate treatment for a child under 2.

What happens if you leave threadworms untreated?

Generally, threadworms don't cause harm. But the itching can make the skin inflamed and irritated, and recurrent waking can lead to tiredness and irritability in the day.

If the worms lay eggs in the vagina, they can cause vaginal itching and discharge. Eggs laid around the urethra (the hole you pee through) can also sometimes lead to bedwetting or problems passing urine. More rarely, threadworms can cause abdominal pain, decrease appetite and lead to weight loss.

How can you prevent children from getting threadworms again?

Threadworms are very contagious but good hand hygiene can help.

Is it true that threadworms make you hungry?

No, threadworms are unlikely to make you hungry.

Is it true that Vaseline or petroleum jelly or eating garlic can stop threadworms?

No, Vaseline and/or garlic are unlikely to help. Please follow my advice above instead.

Pic: Getty Images

Read more:



Dr Philippa Kaye works as a GP in both NHS and private practice. She attended Downing College, Cambridge, then took medical studies at Guy’s, King’s and St Thomas’s medical schools in London, training in paediatrics, gynaecology, care of the elderly, acute medicine, psychiatry and general practice.