Threadworms, also known as pinworms, are one of the most common infections in children. They often cause itching around the bottom at night, which can lead to disturbed sleep and irritability. Although they sound worrying, they are usually harmless and can be treated easily. The challenge is that threadworms spread quickly through households and often come back if not managed properly.
In this guide, we’ll cover what threadworms are, how to recognise them, treatment options, and the best prevention tips for families.
What are threadworms (pinworms) in children?
Threadworms are caused by a small parasite called Enterobius vermicularis. These tiny white worms live inside the intestines and are usually about 1 cm long.
Here’s how they infect children:
- A child swallows microscopic threadworm eggs.
- The eggs hatch in the intestines and grow into adult worms.
- At night, female worms travel to the skin around the anus to lay thousands of eggs, which causes the intense night-time itching.
Because the eggs are very sticky, they can get under fingernails when a child scratches. From there, they spread to toys, bedding, clothing, and even directly back into the child’s mouth. This cycle explains why reinfection is so common.
Signs and symptoms of threadworms in children
The most common symptoms include:
- Itching around the bottom, especially at night
- Disturbed sleep or irritability
- Red or inflamed skin from scratching
- In girls, redness or itching around the vaginal area
- Mild tummy pain or reduced appetite
Most children remain otherwise well. Threadworms do not cause serious illness, but the itching and poor sleep can be frustrating for both children and parents.
How threadworms are diagnosed in children
Often the diagnosis is made by noticing the worms themselves, or because of the classic night-time itching. They look like thin, white threads about 1 cm long and are most likely to be seen 2 to 3 hours after your child has gone to sleep, when the female worms come out to lay eggs around the anus. You might also notice them in the stool, appearing as small white threads that move.
In many cases, treatment is given based on these symptoms, and if the symptoms settle after treatment, that usually confirms the diagnosis.
If you are unsure, your doctor may recommend the “sticky tape test.” This involves pressing a piece of clear sticky tape onto the skin around the anus first thing in the morning, before showering or going to the toilet. The tape is then examined under a microscope for eggs.
Treatment options for threadworms in children
The good news is that threadworms are easily treated with medicines that are safe and effective for children.
Two main types of medication are commonly used:
• Mebendazole: This medicine starves the worms by stopping them from absorbing sugar, which they need to survive. It comes as chewable tablets, chocolate squares, or liquid. Common brands are Combantrin-1 and Vermox. One dose usually clears the worms, but a second dose two weeks later is recommended to kill any newly hatched worms.
• Pyrantel: This medicine works by paralyzing the worms so the body can pass them out in the poo. It comes as tablets or chocolate squares. A common brand is Combantrin. Like mebendazole, one dose is usually enough, but a repeat dose after two weeks is advised.
Both medicines are effective, and most families choose whichever form their child finds easiest to take. Always follow the instructions on the packet, and keep in mind that special precautions may apply for children under two years of age and for pregnant women.
Key treatment points
- Treat everyone in the household at the same time, even if they don’t have symptoms. This helps to break the cycle of reinfection.
- A second dose is usually recommended after two weeks to kill any newly hatched worms.
- Follow the dosage instructions carefully.
Hygiene and prevention tips for threadworms
Treating threadworms is not only about giving medicine. Because the eggs are so easily spread, hygiene plays a key role in preventing reinfection.
- Give your child a shower the night they take the medicine, and again the next morning, to wash away any eggs from the skin
- Change underwear, pyjamas, sheets and towels after treatment
- Wash clothes and bedlinen in hot water to remove and kill any eggs
- Disinfect toilet seats, bathroom surfaces, and frequently touched areas such as door handles
- Vacuum floors regularly to remove any eggs
- Keep fingernails short and encourage regular handwashing, especially before eating and after using the toilet
- Discourage habits like nail biting, thumb sucking, or scratching the bottom
These steps, combined with medicine, help break the cycle and stop worms coming back.
Can threadworms come back after treatment?
Yes, reinfection is very common because eggs can survive on surfaces for up to two weeks. Reinfection usually happens if:
- Hygiene steps are not followed consistently
- Not everyone in the household was treated
- The second dose of treatment is not given after two weeks
- A child picks up eggs again at daycare, preschool, or from close friends
When to see a doctor about threadworms in children
See your doctor if your child has:
- Severe or persistent itching
- Abdominal pain, nausea, or vomiting
- Redness, swelling, or infection around the bottom
- Large worms passed in the stool
- Ongoing symptoms despite treatment
Key takeaways for parents
- Threadworms are common in children and not dangerous.
- They cause itching, poor sleep, and irritability but rarely lead to serious illness.
- Medicines like mebendazole and pyrantel are effective, but hygiene is crucial.
- Treat the whole family and repeat the dose after two weeks.
- Good hygiene helps stop the worms from coming back.
Final word from Dr Sam
Seeing that your child has threadworms (pinworms) can be unsettling, but it is very common and simple to treat. By treating the whole household and sticking to hygiene steps, you can break the cycle and help your child return to restful, itch-free nights.
Frequently Asked Questions
What is the youngest age a child can take threadworm medicine?
Mebendazole is not usually recommended for children under the age of 2, and pyrantel is not usually recommended under the age of 1, unless your doctor advises otherwise.
Do children with threadworms need to stay home from school or daycare?
No. Children with threadworms can continue attending school or daycare once they have started treatment. Threadworms are common and not considered a reason for exclusion. However, it is a good idea to let the school or daycare know so that other parents can check their children and arrange treatment if needed.
Can adults catch threadworms from children?
Yes. Adults can also become infected, especially if they live in close contact with children. That is why treating the whole household at the same time is important.
Can pets spread threadworms to humans?
No. Threadworms only spread from person to person. Humans cannot catch them from dogs, cats, or other animals.
Are threadworms harmful or dangerous for children?
Threadworms are uncomfortable but not dangerous. They rarely cause serious health issues, and weight loss is very unusual. The main problems are itching, disturbed sleep, and irritation of the skin around the bottom.
Written by Dr Samuel Heitner
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