There are several types of worm. The most common in northern Europe is the threadworm, sometimes known as a pinworm, a small parasite that lives inside the intestine.

What causes worms and who can get them?

Threadworms most often affect young children who aren’t fully aware of the importance of hygiene, and might easily forget to wash their hands. But anyone of any age can get them.

When a person has threadworms, the female worms emerge at night to lay eggs around the anus and at the same time they secrete a sticky, itchy mucus. If the person scratches the area, eggs can be transferred on their hands to objects they then touch such as kitchen utensils, toys or toothbrushes. Another person who puts the object in their mouth can then  swallow the eggs which travel to their intestine where they hatch. After a couple of weeks the worms reach adult size, begin to reproduce and the cycle begins again.

What are the signs and symptoms of worms?

Threadworms isn’t always easily identifiable but the key symptom is feeling itchy around the anus at night, which might make it difficult to sleep.

In cases of very heavy infestation, threadworms may cause loss of appetite, weight loss or insomnia.

The worms can be difficult to see because they are white and usually less than one cm long. Sometimes worms and eggs can be found in stools (faeces) - the worms look like small pieces of cotton thread.

How is it normally diagnosed and treated?

Your GP might suggest applying a wide piece of hypo-allergenic tape, or ordinary sellotape, to the skin around the anus at night. You can then take this off in the morning. This will pick up the eggs which can then be identified under the microscope.

If it’s a first case of threadworms, doctors usually suggest simple hygiene measures which should clear the problem up within six weeks including:

• Making sure hands are washed frequently especially before eating and after visiting the toilet;
• Having your own flannel and towel and not sharing them with anyone else in the family;
• Keeping nails short;
• Avoiding eating anything in your bedroom as eggs can be shaken off in bedclothes and survive in dust.

To be really effective, it’s best if the whole family follows these hygiene measures. Also most re-infections do happen at school so it would be worth talking to a teacher. You won’t need to stay away from class but the staff might like to consider the above hygiene measures.

What if it doesn’t clear up within six weeks?

Go back to your GP. There is medication available that can remove threadworms that are proving tricky to shift. All members of the family or household will need to be treated at the same time, to avoid re-infestation, even if they do not show symptoms.

Your GP may also suggest some more stringent hygiene tactics including:

• Daily vacuuming of carpets and damp-dusting surfaces;
• Daily disinfecting of bathroom surfaces;
• Wearing fitted underwear at night;
• Changing and washing all nightwear every day and also bed linen if possible;
• Washing around the anal area first thing every morning.
• Rinsing toothbrushes before use.

For more help and information

If you would like to know more about worms, please ask your doctor.

Also visit: www.nhsdirect.nhs.uk

Last reviewed by Great Ormond Street Hospital: 3 November 2006

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