What should you know about the cause of threadworms?

Adult worms live in the bowel. At night, female worms move around the anus and lay eggs, causing itching. Scratching can place eggs under fingernails; touching food, toys or shared surfaces can then spread them. Another person may swallow the eggs and become infected. Eggs can remain on fabrics and objects for a period, which explains why infection may circulate among people living together. Night-time itching is common, but some people have no noticeable symptoms. Abdominal discomfort or bedwetting can occur and deserves assessment if it persists.

Follow the treatment instructions given by a pharmacist or clinician, including advice about household members and any repeat dose. Wash hands carefully after using the toilet and before eating, keep fingernails short, avoid nail biting, and bathe or shower in the morning. Change underwear and sleepwear regularly, wash bedding and towels, and clean frequently touched surfaces. Launder fabrics on a hot cycle when suitable for the material. These measures remove eggs and reduce the chance of swallowing them again.

Arrange a GP Consultation if itching continues after treatment, returns repeatedly, affects sleep, or causes broken skin. Seek advice for persistent abdominal pain, marked irritation around the anus, or symptoms in a very young child or during pregnancy, when medication choices need individual review. Urgent help is appropriate for severe abdominal pain, vomiting, or a child who appears very unwell rather than simply itchy.

Ask which treatment is suitable, whether people sharing your home should be treated, when a repeat dose is needed, and how long enhanced hygiene should continue. Mention pregnancy, breastfeeding, regular medicines, or skin broken by scratching.