Threadworms (springmask in Swedish, also called pinworms) are small white worms that live in the gut and lay their eggs around the anus at night, causing itching and restless sleep. They are harmless, very common among preschool children and treated with an over-the-counter medicine from the pharmacy, usually for the whole family and in two rounds two to three weeks apart. The child can go to förskola (preschool) as soon as treatment has started.
Threadworms are one of those things nobody mentions at the parents' meeting, and that almost every family with a preschooler gets at some point. It is not a sign of poor hygiene, it is a sign that your child has friends. Here is how to recognise them and get rid of them.
It is eleven o'clock on a Sunday night in Huddinge. The four-year-old has woken for the third night in a row, crying and scratching her bottom, and nobody knows why. You take a torch, look, and see something small and white moving. It is unpleasant for three seconds. Then it is a relief, because now you know what it is, and it can be fixed with a trip to the pharmacy tomorrow.
Signs
- An itchy bottom, especially in the evening and at night when the females lay their eggs
- Restless sleep, the child wakes up and scratches
- Redness and irritation around the anus
- In girls, sometimes itching around the vulva
- White, thread-like worms, a few millimetres long, visible in the stool or around the anus in the evening with a torch
How threadworms spread
The female crawls out at night and lays thousands of eggs in the skin around the anus. It itches, the child scratches in their sleep, and the eggs end up under the fingernails. From there they travel to the mouth, to the breakfast sandwich, to a sibling's toy, to the door handle at förskola. The eggs survive for several weeks at room temperature, in bedding, on the floor and in dust. A child who swallows eggs has worms a few weeks later, and then it starts all over again. That is why treatment is always two things at once: medicine that kills the worms, and washing and nail care that deal with the eggs. One without the other is not enough.
How to confirm it
Look with a torch around the anus an hour or two after the child has fallen asleep. If you see the worms, that settles it. The pharmacy also sells a tape test: a piece of clear tape pressed against the skin in the morning, before showering, which you hand in at your vårdcentral (local health centre) for analysis. If you are unsure and the child only scratches now and then, it could also be dry skin, eczema or a bottom wiped too hard. Look three evenings in a row before you buy the medicine.
Treatment
- Medicine from the pharmacy, over the counter. The pharmacy advises on the dose by weight and on who in the family can be treated.
- The whole household at the same time, including those without symptoms.
- Repeat after two to three weeks. The medicine kills the worms but not the eggs, and new ones hatch.
- Wash bedding, towels and pyjamas at 60 degrees or hotter at the time of both treatments.
- Vacuum the bedrooms and wash toys that often end up in mouths.
Day by day: what three weeks look like
| When | What you do |
|---|---|
| Day 1, morning | Everyone in the household takes their dose. The child showers, nails are cut. All bedding, pyjamas and towels washed at 60 degrees. Vacuum the bedrooms |
| Days 1 to 7 | A shower or a wash of the bottom every morning. Clean underwear every day. Hands washed after the toilet and before meals |
| Days 2 to 3 | The itching usually eases. If it gets worse or the child has stomach pain: call 1177 (the national healthcare helpline) |
| Days 7 to 14 | Keep up the morning routine. Change the bedding at least once more. Cut the nails again |
| Days 14 to 21 | Second dose for everyone, on the same day. Wash all bedding again, vacuum again |
| After day 21 | Done. If the itching returns within a few weeks: contact a healthcare professional before running a third round |
Hygiene that breaks the cycle
| Do | Why |
|---|---|
| Short nails, brush underneath them | The eggs get stuck under the nails when the child scratches |
| A shower or a wash of the bottom every morning | Rinses away the night's eggs |
| Wash hands after the toilet and before meals | The eggs travel from hand to mouth |
| Clean underwear every day, pyjamas often | Reduces the number of eggs in the bed |
| Close-fitting pyjama bottoms at night | Harder to scratch in their sleep |
What does not help
Bathing the child every evening does not help, it is the morning that counts, when the night's eggs need to go. Changing the diet does not help, threadworms do not care about sugar. Telling the child off for scratching does not help either, they do it in their sleep. And treating only the child and skipping the adults is the most common reason it comes back: adults often have threadworms without noticing.
When to seek care
- The child is under two. The medicine is not intended for the smallest children without medical advice, call 1177 or your vårdcentral.
- Someone in the family is pregnant or breastfeeding. Talk to the midwife or the pharmacy before treatment.
- The itching remains after two complete treatments with washing. Then it may be something else, or a source of infection outside the home.
- The child has stomach pain for several days, blood in the stool or a fever. That is not typical of threadworms.
- The skin around the anus has become sore and infected from scratching.
Tell förskola and the other parents
It feels embarrassing, but förskola has seen it a hundred times and the staff are grateful to know. They remind the children about handwashing and keep an eye on children who are scratching. Do tell the parents of your child's closest friends too, those children often have the same thing and nobody has worked it out yet. The more families who treat at the same time, the lower the risk of it going round the group all autumn. Conjunctivitis, Hand, foot and mouth disease in children and threadworms are förskola's three most common autumn complaints, and all three have the same cure: handwashing.
How we do it with our families
The nanny is often the one who notices the scratching at a nappy change or in the evening, and she tells you the same day. Nike has a family in Sundbyberg with two children, aged three and six, and it was she who saw the three-year-old scratching on the changing table two Thursdays in a row. She wrote it on the note, mum looked with a torch that same evening, and by Friday the whole family had been treated. During the treatment weeks she helps with the morning routine if she is there: shower, clean clothes, nails. With this family she took on the laundry on Thursdays, so the bedding went through at 60 degrees on the same day as dose two. It is the boring work that stops it coming back.
This text is general information and does not replace advice from BVC (the child health clinic every family is enrolled in), your vårdcentral or 1177. If you are worried about your child, call 1177. In an emergency, call 112.
Would you like a nanny who knows your child, knows how things usually are and notices when something is different? Book a free first meeting with the nanny in your home.
Read more: Hand, foot and mouth disease in children · Conjunctivitis in children · Potty training · Frequently asked questions
Frequently asked questions
How do you know if your child has threadworms?
The child scratches their bottom, mostly in the evening and at night, sleeps restlessly and is sometimes sore around the anus. Sometimes the worms are visible: white, thin as thread, a few millimetres long, in the stool or around the anus in the evening if you look with a torch an hour after the child has fallen asleep. If you see nothing but still suspect it, the pharmacy sells a tape test.
Does the whole family have to be treated?
Yes, that is usually recommended because the infection spreads easily within a household and often without symptoms. The medicine is available over the counter at pharmacies, and the pharmacy advises on the dose and who should be treated. Children under two and pregnant women should not take the medicine without first talking to a healthcare professional or the pharmacy. Everyone takes their dose on the same day, and everyone takes the second dose on the same day.
Can the child go to förskola?
Yes, as soon as treatment has started. Threadworms are no reason to stay at home, and the child is no more contagious that day than they have been for the past few weeks. Tell förskola so they can keep an eye on other children and remind everyone about handwashing. Most förskolor have seen it many times and will not be surprised.
Why does it come back?
The eggs survive for several weeks on bedding, toys and under nails, and the medicine only kills the worms, not the eggs. That is why the treatment is repeated after two to three weeks, when new worms have hatched but not yet laid eggs, and the bedding is washed at the time of both doses. If you skip the washing or the second dose, the most common result is that it starts all over again.
Are threadworms dangerous?
No. Threadworms are a nuisance but harmless, and they cause no lasting damage. What they disturb most is sleep, and a child who has scratched can get small sores that sting. Seek care if the itching does not ease after two treatments, if the child has stomach pain for several days, if there is blood, or if the child is under two and you are unsure about the treatment.