Threadworms (Pinworms) in Children: Symptoms, Treatment and Stopping the Itch
Quick answer
Threadworms — also called pinworms — are tiny white, thread-like worms that live in the bowel. They are the most common worm infection in Australian children and are very common, harmless and not a sign of poor hygiene. The classic sign is an itchy bottom, worse at night. They are treated with a single-dose worming medicine from the pharmacy, taken by the whole household and repeated two weeks later, alongside good hand-washing. Children do not need to stay home from school.
On this page
- What are threadworms?
- What do threadworms look like?
- What are the symptoms of threadworms?
- How do you get threadworms?
- Are threadworms and pinworms the same?
- How do you get rid of threadworms?
- How do you stop the itching at night?
- How do you stop threadworms coming back?
- Can adults get threadworms?
- Are threadworms dangerous?
- Do children need to stay home from school?
- When to see a doctor or pharmacist
- FAQs
What are threadworms?
Threadworms are small, white, thread-like worms (medical name Enterobius vermicularis) that live in the bowel. They are the most common worm infection in children in Australia, especially those of school and preschool age. Threadworms are very common, generally harmless, and — despite how it can feel — not a sign of a dirty home or poor parenting. Almost any child can pick them up, and most will at some point.
What do threadworms look like?
Adult threadworms look like tiny pieces of white cotton thread, usually about 5 to 13 millimetres long — roughly the size of a staple. You may spot them moving around your child's bottom at night, or see them in the toilet or in a nappy. Threadworm eggs, on the other hand, are microscopic: you cannot see them with the naked eye, which is how they spread so easily without anyone noticing.
What are the symptoms of threadworms?
The tell-tale threadworm symptom is an itchy bottom, and it is typically worse at night — that is when the female worms come out to lay their eggs around the anus. Other common signs include:
- Restless, broken sleep and irritability
- Itching or irritation around the vulva in girls
- Fidgeting or scratching at the bottom during the day
- Occasionally, mild tummy discomfort
Many children have no symptoms at all. Threadworms do not usually cause a fever — if your child has a temperature as well, something else may be going on, so it is worth checking with a forehead thermometer and reading our guide to toddler fever.
How do you get threadworms?
Threadworms spread when a child swallows the eggs. The cycle is simple: a female worm lays eggs around the bottom at night, the itching makes the child scratch, and the eggs get caught under their fingernails. From there they travel to the mouth — through nail-biting, thumb-sucking or eating without washing hands — or onto toys, bedding, towels, food and surfaces, where other people pick them up. Threadworm eggs can survive on surfaces for up to two to three weeks, which is why whole families and classrooms often catch them together.
Are threadworms and pinworms the same?
Yes. Threadworm and pinworm are two names for the same worm, Enterobius vermicularis. "Threadworm" is the common term in Australia and the UK, while "pinworm" is used more in the United States. They are not the same as roundworms or tapeworms, which are far less common in Australian children. Here is how the three compare:
| Threadworms (pinworms) | Roundworms | Tapeworms | |
|---|---|---|---|
| What they look like | Tiny white threads, up to about 1 cm | Longer, pale worms resembling earthworms | Long, flat, ribbon-like segments |
| Main symptom | Itchy bottom, worse at night | Often none; sometimes tummy upset | Often none; segments seen in the poo |
| How common in AU children | Very common | Uncommon | Rare |
| Treatment | Pharmacy worming medicine for the whole household | See a GP | See a GP |
How do you get rid of threadworms?
Threadworms are treated with a worming medicine you can buy over the counter at any pharmacy — the active ingredient is usually mebendazole or pyrantel. These are effective and considered very safe for children over the age of two; ask your pharmacist for advice on younger children, or if your child is pregnant, breastfeeding or has other health conditions.
Two rules make treatment work:
- Treat the whole household at the same time — everyone who lives with your child, even those with no symptoms, because threadworms spread silently.
- Repeat the dose two weeks later. Worming medicine kills the adult worms but not the eggs, so a second dose clears any worms that hatch afterwards.
Pair the medicine with the hygiene steps below — on their own, tablets often are not enough to stop reinfection.
How do you stop the itching at night?
The night-time itch is the worst part for most children. Alongside the worming medicine, a warm bath or shower first thing in the morning washes away eggs laid overnight, and dressing your child in close-fitting underwear or pyjama pants makes it harder for them to scratch in their sleep. Keeping fingernails short and clean, and gently discouraging scratching, both reduce the itch and slow the spread. If the skin around the bottom becomes very red, broken or sore, see your pharmacist or GP.
How do you stop threadworms coming back?
Reinfection is extremely common, and good hygiene is what breaks the cycle. On the day you treat the family, and for a couple of weeks after, focus on these habits:
- Wash hands well with soap and water after the toilet and before eating, and scrub under the nails. Keep hand sanitiser handy for when you are out. See why hand-washing matters so much.
- Keep nails short and discourage nail-biting and thumb-sucking.
- Shower in the morning to rinse away eggs laid overnight.
- Wash bedding, nightwear and towels in hot water on treatment day, and avoid shaking them (which scatters eggs).
- Damp-dust and vacuum bedrooms, and do not share towels or face washers.
These are the same everyday habits that help with lots of childhood bugs — our guide to teaching children good hygiene has more.
Can adults get threadworms?
Yes. Threadworms are most common in young children, but adults and older siblings catch them easily — usually from a child in the house. That is exactly why the whole household is treated together. Parents should be especially careful with hand-washing while treating a child, particularly after changing bedding or helping in the bathroom.
Are threadworms dangerous?
No. Threadworms are a nuisance rather than a danger. They do not burrow into other organs, they do not cause serious illness, and they will not harm your child's long-term health. The main problems are the itch, disturbed sleep and the ease with which they spread. Rarely, heavy or long-standing infections can cause more irritation, so it is worth treating them promptly — but there is no need to worry that threadworms are dangerous.
Do children need to stay home from school?
No. Under Australian guidance, children with threadworms do not need to be kept home from school or childcare. It is best to start treatment and a good hand-washing routine before they go back, but there is no exclusion period — unlike infections such as school sores and chickenpox, which do keep children at home. Letting the school or centre know can help them remind families about hand hygiene if worms are going around.
When to see a doctor or pharmacist
Threadworms can almost always be managed at home with pharmacy medicine and hygiene. Speak to your pharmacist or GP if:
- Your child is under two, pregnant, or breastfeeding, or you are unsure which treatment to use
- The worms keep coming back despite treating everyone and following the hygiene steps
- The skin around the bottom is very sore, broken or looks infected
- There is blood in the poo, weight loss, ongoing tummy pain or a fever — these are not typical of threadworms and need review
For advice any time, call healthdirect on 1800 022 222 (or 13 HEALTH on 13 43 25 84 in Queensland). In an emergency, call 000.
Frequently asked questions
Will threadworms go away on their own?
They can eventually, but they usually do not without help, because children keep reinfecting themselves and each other. Treating the whole household with pharmacy worming medicine, plus good hand-washing, is the reliable way to clear them.
What do threadworm eggs look like?
Threadworm eggs are microscopic and cannot be seen with the naked eye. You can only see the adult worms, which look like tiny white cotton threads around the bottom or in the toilet.
Do I need to treat the whole family?
Yes. Everyone in the household should take the worming medicine at the same time, even without symptoms, and repeat the dose two weeks later. Threadworms spread silently, so treating only one person usually means they come straight back.
Can threadworms make my child sick or lose weight?
Threadworms rarely cause anything beyond an itchy bottom and broken sleep. They do not typically cause weight loss, fever or serious illness. If your child has those symptoms, see your GP, as another cause is more likely.
How long does it take to get rid of threadworms?
The medicine starts working straight away, but because a second dose is needed after two weeks and eggs can linger on surfaces, plan on about two to three weeks of treatment and hygiene to clear them fully.
Related reading
Working through other childhood bugs? See our guides to school sores (impetigo), chickenpox and other common childhood illnesses, and browse the full FeverMates range in our online shop.
Sources
Royal Children's Hospital Melbourne; healthdirect Australia; Raising Children Network; Better Health Channel (Victoria). Reviewed against Australian guidance.
This article is general information only and is not a substitute for medical advice. If you are unsure how to treat your child or worried about their health, speak to your pharmacist or GP, call healthdirect on 1800 022 222, or in an emergency call 000.