To successfully treat threadworms, all household members must be treated, even if they have no symptoms.
This is because the risk of the infection spreading to other people in the same household is very high.
The aims of treatment are to get rid of the threadworms and prevent re-infection. This will usually involve a combination of medication to kill the worms and strict hygiene measures to stop the spread of the eggs.
The main medication used to treat threadworms is available from your local pharmacy without prescription, but make sure you follow the manufacturer’s instructions because it is not suitable for everyone.
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 not usually the same as for most other people. See below for treatment advice in these circumstances.
Mebendazole is the main medication used to treat threadworm infections. It can be bought over the counter from your local pharmacy or prescribed by your GP and is available as a chewable tablet or as a liquid.
Mebendazole works by preventing the threadworms from absorbing sugar (glucose), which means they should die within a few days.
This medication is 90%-100% effective at killing the threadworms, but it doesn't kill the eggs. This is why the hygiene measures outlined below should also be followed for six weeks.
Visit your GP if the infection continues two weeks after treatment. They may recommend a second dose of medication.
In rare cases, mebendazole can cause abdominal pain or diarrhoea, particularly if the threadworm infection is severe.
Strict hygiene measures can help clear up a threadworm infection and reduce the likelihood of re-infection.
The life span of threadworms is approximately six weeks, so it's important that the hygiene methods are followed for at least this long. Everyone in the household must follow the advice outlined below
- Wash all night clothes, bed linen, towels and soft toys when you are first diagnosed. This can be done at normal temperatures but make sure that the washing is well rinsed.
- Thoroughly vacuum and dust the whole house, paying particular attention to the bedrooms. This should be repeated regularly.
- Carefully clean the bathroom and kitchen by damp-dusting surfaces and washing the cloth frequently in hot water. This should be repeated regularly.
- Avoid shaking any material that may be contaminated with eggs, such as clothing or bed sheets. This will help prevent eggs being transferred to other surfaces.
- Don't eat food in the bedroom, because you may end up swallowing eggs that have been shaken off the bedclothes.
- Keep your fingernails short. Encourage other members of your household to do the same.
- Discourage nail-biting and sucking fingers. In particular, make sure that children don't suck their thumb.
- Wash your hands frequently and scrub under your fingernails, particularly before eating, after going to the toilet and before and after changing your baby's nappy.
- Wear close-fitting underwear at night and change your underwear every morning.
- Bath or shower regularly, particularly first thing in the morning. Make sure that you clean around your anus and vagina to remove any eggs.
- Ensure that everyone in your household has their own face flannel and towel. Don't share towels.
- Keep toothbrushes in a closed cupboard and rinse them thoroughly before use.
Children can easily pick up another threadworm infection from friends or at school, so maintaining good hygiene may help prevent re-infection.
If you are pregnant or breastfeeding
If you are pregnant or breastfeeding, medication is usually not recommended. Instead, you are advised to follow the hygiene measures above.
See your GP if you are more than three months pregnant or if you are breastfeeding and you continue to experience problems using only the hygiene measures. In certain circumstances, your GP may consider prescribing medication.
If a child under two years old has threadworms
Mebendazole is not licensed for use in children under two years of age, but GPs may choose to prescribe it ‘off-label’ (outside its licence) for children who are over six months of age.
If medication is not used, the hygiene measures outlined above are recommended instead.
Make sure that you wash your baby’s bottom gently but thoroughly every time you change their nappy. Also wash your hands thoroughly before and after changing their nappy.
Do I need to avoid work or school?
If you or your child has a threadworm infection, 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 take steps to limit the spread of infection
Page last reviewed: 28/08/2013
Next review due: 28/08/2015