Washing hands can help prevent a threadworm infection 

Should work or school be avoided?

A threadworm infection should be treated as soon as it's identified, but it is not necessary to stay off work or school.

However, it's important to inform your child's school or nursery so they can follow good hygiene practices to limit the spread of infection – such as cleaning toys and equipment, and encouraging children to wash their hands regularly.

Threadworms, also known as pinworms, are tiny parasitic worms that hatch eggs in and infect the large intestine of humans.

Threadworms are the most common type of worm infection in the UK, and they are particularly common in young children under the age of 10.  

Threadworms are white and look like small pieces of thread. You may notice them around your child's bottom or in your or your child's stools.

They don't always cause symptoms, but people often notice itchiness around their bottom or vagina. This can be worse at night and can sometimes disturb sleep.

Read more about the symptoms of threadworms.

When to see your GP

If you think you or your child may have threadworms, you can usually treat the infection yourself with medication available at pharmacies without prescription.

You only usually need to see your GP if you think you have threadworms and you are pregnant or breastfeeding, or if you think your child has threadworms and they are under two years old. This is because the treatment recommended in these circumstances is usually different to what is recommended for most people.

How are threadworms spread?

Threadworms lay their eggs around an infected person's anus (bottom), usually at night. Along with the eggs, the worm also secretes a mucus that causes itching.

If the eggs get stuck on the person’s fingertips when they scratch, they can be transferred to their mouth or onto surfaces and clothes. Other people who touch an infected surface can then transfer the eggs to their mouth.

Threadworm eggs can survive for up to three weeks before hatching. If the eggs hatch around the anus, the newly born worms can re-enter the bowel. Eggs that have been swallowed will hatch inside the intestine. After two weeks, the worms reach adult size and begin to reproduce, starting the cycle again.

Read more about what causes threadworms.

Treating threadworms

If you or your child has threadworms, everyone in your household will need to be treated because the risk of the infection spreading is high. This includes people without any symptoms of a threadworm infection.

For most people, treatment will involve a single dose of a medication called mebendazole to kill the worms. Another dose can be taken after two weeks, if necessary.

During treatment and for a few weeks afterwards, it is also important to follow strict hygiene measures to avoid spreading the threadworm eggs.

This involves things such as regularly vacuuming your house and thoroughly washing your bathroom and kitchen.

If you are pregnant or breastfeeding, hygiene measures are usually recommended without medication. This is also often the case for young children. 

Read more about treating threadworm infections.

Preventing threadworms

It is not always possible to prevent a threadworm infection, but you can significantly reduce your risk by always maintaining good hygiene and encouraging children to do the same.

Children should wash their hands regularly, particularly after going to the toilet and before mealtimes. Kitchen and bathroom surfaces should be kept clean.  

If your child is infected, encouraging them not to scratch the affected area around their anus or vagina will help prevent re-infection and reduce the risk of the infection spreading to other people.

Page last reviewed: 28/08/2013

Next review due: 28/08/2015


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The 8 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Goolzy said on 19 August 2014

Hi there, I just wanted to put it out there that the medication that you buy from a local pharmacist works fine. I'm 14 years old and id had threadworms for almost 6 months before actually spotting them!!! Then even though I didn't want to I told my mum and she bought some tablets I only had to take two over 2 weeks and then they were gone!
I am writing this because I remember when I looked on here I read through everything above and calmed down from the worried state I was in from just finding out! Then I read the comments and started freaking out! So for anyone panicking calm down you'll be fine and anyway they don't actually do much I mean if they did id of found out within 6 months surely!

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BA13 said on 30 October 2013

Please can anyone help I want to doctors yesterday because I have threadworm they gave me tablet called mebendazole just wording how long it takes to work also what else could I take to relive the itching

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Jan 80 said on 03 August 2013

Hi Mcv1, Im sure you have probably done all this but, have you gone into school to inform them of the infection? After alot of persistance my childrens school sent out leaflets to inform all the parents-I know that not all parents will acknowledge the leaflet some will not even read it but the majority will. Also the school once informed should carry out a 6 week strict cleaning regime too.

I change the beds every week and sometimes twice weekly. Bathrooms get done twice a week too. Door and dorr handles and stair banister cleaned once/twice a week.
My daughter wears knickers undre her pjs too and changed/washed daily.

I hope this helps a little- I am very paranoid about this infection and so i completely understand your frustration and anguish.


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Mcv1 said on 12 June 2013

My daughter suffers every couple of months with worms. I Am sick of it, I've just put together a toiletry bag for school as they never seem to have soap in the dispensers. And I have banned her from using school pens and pencils she now takes her own.
The itching drives her insane,bless her, awake until 1- 2 in the morning crying !
She regularly washes her hands, I've shown her how to do it correctly etc, she tells me she washes them at school, and she has an anti bacterial gel to apply after washing what else can I do ??
She is not re infecting herself, I'm very careful using separate hand towels and taking the tablets 2 weeks after the first dose etc.
she just seems susceptible to them :(

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Jan 80 said on 21 May 2013

This problem is something that really upsets me, especially as I have followed all the hygiene procedures all the time and carry them on. During and after treatment. My daughter has unfortunaly had this 4 times! I feel like I will never be rid no matter what I do. I had informed school who had straight away got on to cleaning the school but didnt want to inform parents i do not understand how we can stop re infection if other children are not treated within the school/nursery setting. I am hoping that the school will now inform parents after I had spoke to them again.

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Donnio said on 17 January 2013

It states that all people in a household should be treated to prevent infection but yet children in the school who the they spend all day with dont automatically get treated. Instead they are sent back to school as its compulsory to go to be reinfected and infect others. Children aren't encouraged and reminded to wash hands before eating lunch and snacks or especially after using the toilet. It's about time the nhs treated schools and families all at the same time to rid of this problem. My child's 3rd infection and I thinks it's appalling more isnt done to stop this :(

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nikkinu said on 23 January 2012

vicky i,m so glad i saw your post i work in the same environment as you and work with a lady who presents all the symtoms of having thread worms i also work closely with this person and am trying to assertain whether we now need to treat other service users and all the staff working alongside her i think this is probably quite common amongst people working and living in an institutionalized environment...

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Vicky 2 said on 09 February 2011

Reading this article has given me a lot more insight into such a common, but unbeknown problem to a lot of people.

I am a support worker who caters for institutionalized people with learning disabilities. One of my service users has just told me he has "the worms" and I have been working with this person very closely. After reading this article, I am definitely going to get checked and treated by my as I have also read somewhere that some people can have no symptoms or aweareness at all.

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