Patient information · Paediatrics and family health
Threadworms
treat everyone, on the same day
Threadworms are extremely common in children and say nothing whatsoever about household cleanliness. They are easily treated. The reason they keep coming back is almost always that only the affected child was treated, or that the hygiene measures stopped after a few days.
Contact us before treating if
- the affected person is pregnant or breastfeeding
- the child is under two years old
- there is weight loss, tummy pain or blood in the stool
- the itching has caused broken, weeping or infected skin
- worms are still present after two courses of treatment
- a girl has vaginal itching or discharge that is not settling
Over-the-counter treatment is not suitable for everyone, which is why these situations need advice first rather than a trip to the pharmacy. Threadworms themselves are not dangerous and are not an emergency.
Recognising them
- Intense itching around the bottom, worse at night — this is the classic sign, because the female worm emerges to lay eggs in the evening.
- Disturbed sleep, irritability and tiredness.
- Fine white threads, about a centimetre long, visible in the stool or around the anus — look with a torch two or three hours after the child has fallen asleep.
- In girls, itching or irritation around the vulva.
- Some people have no symptoms at all, which is exactly why everyone in the house is treated.
Treatment
- Treat every single person in the household on the same day, whether or not they have symptoms. This is the step people skip, and it is the reason threadworms recur.
- Use mebendazole, available from a pharmacy without prescription for anyone over two years old. It is a single dose.
- Start the hygiene routine the same day and continue it for two weeks — the medicine kills the worms but not the eggs already laid.
- Take a second dose after two weeks if advised, or if symptoms return — ask your pharmacist.
Hygiene for two weeks is not optional
Eggs survive on surfaces for up to two weeks and are microscopic. A child scratches at night, gets eggs under their fingernails, and reinfects themselves the next morning. Medicine alone, without the fortnight of hygiene, has a high failure rate. This is the part that determines whether it works.
The two-week routine
Every morning
- Shower or bathe first thing, washing around the bottom — this removes eggs laid overnight
- Change and wash underwear, nightwear and towels
- Wash hands and scrub under the nails after using the toilet and before eating
Through the fortnight
- Wash bedding, nightwear and towels on a hot wash — do not shake them, which scatters eggs
- Vacuum and damp-dust regularly, especially bedrooms
- Keep fingernails short; discourage nail biting and thumb sucking
- Wear close-fitting pants at night; avoid sharing towels or flannels
Pregnancy, breastfeeding and under-twos
Mebendazole is not usually recommended in pregnancy, while breastfeeding, or for children under two. In these situations the hygiene measures alone will normally clear the infection within about six weeks, because the adult worms have a short lifespan and reinfection is what sustains them. Speak to us before taking anything — there are circumstances where treatment is appropriate, and it should be a considered decision.
School, nursery and everyday life
- Children do not need to stay off school or nursery.
- Tell the school or nursery so other families can check, but there is no stigma here — threadworms are simply very common in groups of young children.
- Reinfection is common. If it happens, repeat the whole process rather than treating only the affected child again.
- Pets do not carry human threadworms and do not need treating.
Book an appointment if treatment has failed twice, someone in the house is pregnant or under two, the itching has caused a skin infection, or you would like the diagnosis confirmed. We see families seven days a week and can prescribe where over-the-counter treatment is not appropriate.
Seen today, not next week
Same-day appointments most days, seven days a week, 9am–7pm, on Whitechapel Road.
Tower Bridge Hospital London
97–99 Whitechapel Road, London E1 1DT
WhatsApp 07903 284 189
info@mhwclinic.co.uk
Open Mon–Sat, 9am–7pm (closed Sundays until September)
In an emergency
Call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
When we are closed and it is not an emergency
Call NHS 111 or visit 111.nhs.uk.