Threadworms (Pinworms) in Children — Irish Family Guide

What are threadworms?

Threadworms (also called pinworms; medical name Enterobius vermicularis) are small white worms about 1 cm long that live in the lower gut. They are the most common parasitic infection in children in Ireland, affecting an estimated 40% of under-10s at some point. They are not a sign of poor hygiene — they spread easily in any household, school, or creche through microscopic eggs on hands, surfaces, and bedding.

The adult worms come out around the anus at night to lay eggs, which causes the classic itching.

Symptoms

• Itching around the anus, especially at night — the most characteristic symptom
• Disturbed sleep, irritability
• Sometimes visible white threads (~1 cm) in the toilet bowl or around the anus, often at night
• In girls: occasional vulval itching
• In some children, no symptoms at all

Threadworms do not cause weight loss, fevers, or significant abdominal pain in typical cases.

Diagnosis

Diagnosis is usually clinical — based on the typical history. Confirmation isn't required to treat. Per NICE CKS, if confirmation is wanted:

• Sellotape test: apply clear sticky tape to the skin around the anus first thing in the morning before bathing or wiping. Eggs adhere to the tape and can be seen with a microscope. Available via your treating doctor.
• Sometimes worms are visible on the perianal skin or in the stool

Treatment — the whole household

Per NICE and ICGP guidance:

• Mebendazole — single dose, with a repeat dose 2 weeks later (to catch eggs that hatched after the first dose). Available over-the-counter in Irish pharmacies for ages 2+. For under-2s and pregnant women, alternative approach via medical advice.
• Pyrantel pamoate — alternative
• Treat all household members (over age 2) at the same time, even if asymptomatic — otherwise reinfection cycle continues

Hygiene measures — equally important

Medication kills adult worms; hygiene breaks the egg-spread cycle. For 2 weeks after treatment:

• Wash hands thoroughly with soap before meals, after using toilet, after waking up
• Keep fingernails short and clean — discourage nail-biting
• Shower or bath in the morning (not just evening) to remove eggs laid overnight
• Wash bedding, towels, and nightwear at 60°C or above
• Vacuum carpets and damp-dust surfaces
• Avoid shaking out bedding or clothes (spreads eggs)

When to seek help

Online Doctor consultation is appropriate for: confirming the diagnosis, advice on treatment, recurring episodes, or treatment in pregnancy. Seek in-person review if: under-2s with suspected threadworms (treatment options differ), recurrent infestation despite proper treatment and hygiene, or atypical symptoms (significant abdominal pain, weight loss — suggests another diagnosis).

Online Doctor consultation

An Online Doctor can assess, advise on appropriate treatment, prescribe alternatives where over-the-counter is not suitable (pregnancy, under 2s, certain medical conditions), and provide reassurance.