Online Threadworm Consultation

Threadworms are small, thin, white worms, usually somewhere between 2mm and 13mm long, that live in the large intestine. An infection starts when someone swallows a microscopic worm egg, often without realising it. Once inside the gut, the eggs hatch and grow into adult worms over the following month or two. At night, female worms travel out through the anus to lay their own eggs on the surrounding skin, which is what triggers the intense itching that most people notice first, particularly once they're warm in bed.

The eggs are extremely sticky and cling easily to fingers during scratching. From there they transfer to anything touched afterwards: clothing, bedsheets, toys, door handles, kitchen surfaces, and eventually another person's hands or mouth. According to the NHS, the eggs can survive for up to two weeks outside the body, which explains why threadworms move through a household or a classroom so efficiently, and why one round of treatment often isn't enough if hygiene measures aren't followed alongside it. Young children are particularly prone to reinfecting themselves and others, since they're more likely to forget to wash their hands after using the toilet or before eating, and more likely to put their fingers in their mouth.

Most of the time, threadworms are diagnosed from symptoms alone, without any need for testing. The clearest sign is itching around the anus (or the vagina, in girls) that's usually worse at night, sometimes disturbing sleep for the whole family. Some people also notice small, thread-like white worms in their stool, or occasionally around the anus itself shortly after going to bed. Symptoms can be much milder in adults, and it's not unusual for a parent to only find out they have threadworms because a child has been diagnosed first.

As part of our online consultation, you'll describe the symptoms you or your child are experiencing, along with some background on general health and any other medicines being taken. Our pharmacist reviews this information against our Patient Group Direction criteria to confirm whether treatment can be supplied. In situations where the picture isn't straightforward, such as symptoms that don't fit the usual pattern, or when someone doesn't respond to treatment as expected, we'll always recommend following up with a GP rather than repeating medication that isn't working.

We offer Ovex (mebendazole) in two forms: a chewable tablet and a banana flavoured oral suspension, so there's a suitable option whether you're treating an adult, an older child who can manage a tablet, or a younger child who finds liquid medicine easier to take. Mebendazole works by stopping the worms from being able to absorb sugar, which causes them to die off over the following day or so. It doesn't kill the eggs, which is why the medicine alone isn't the whole solution.

For most people, a single dose is enough. If symptoms come back, a second dose two weeks later is sometimes recommended, since this covers any eggs that were swallowed around the time of the first dose before they had a chance to mature. The NHS medicines guide for mebendazole explains that dosing differs for other worm infections, so it's worth confirming with a pharmacist that what you're treating is, in fact, threadworms rather than something else. Because it's not suitable for everyone, our pharmacist checks for anything that might affect suitability, including pregnancy, breastfeeding, and treatment for children under 2, before any order is approved.

Medication clears the worms already living in the gut, but it doesn't remove eggs that have already been laid on skin, clothing or bedding, and those eggs can survive for up to two weeks in the environment. That's why the advice alongside treatment always includes a run of hygiene steps for around two weeks afterwards, to stop the household from simply reinfecting itself.

The habits that make the biggest difference are simple: washing hands and scrubbing under fingernails after using the toilet, before eating, and after changing a nappy; keeping fingernails short and discouraging nail biting or scratching; and washing sleepwear, sheets, towels and soft toys on a hot cycle for several days after treatment, since heat is what actually destroys the eggs. Vacuuming bedrooms and wiping down kitchen and bathroom surfaces with hot water helps too, and it's worth avoiding shaking out clothing or bedding before washing it, since this can scatter eggs around a room rather than containing them.

Because threadworms spread so easily within a household, treating everyone aged 2 and over at the same time, even family members without symptoms, gives the best chance of clearing the infection for good rather than passing it back and forth over the following weeks.