Information Sheet for Patients
What are threadworms?
Threadworms live in the bowel and around the bottom. They are tiny white worms about half an inch
long which look like "threads" of white cotton- hence the name threadworms.
Are they harmful?
Threadworms are generally harmless. They can cause irritation around the bottom, which can be
distressing and embarrassing for the sufferer and can be aggravated by scratching. Threadworms do
not usually cause any long term damage.
Who gets threadworms?
Threadworms are a very common problem, particularly in children. 40% of children below the age of
10 years are infected with threadworms, but many may not show the "itching" symptoms.
How can I tell if someone has threadworms?
The most common sign is scratching of the bottom, particularly at night. This may be associated with
disturbed sleep and irritability and so the scratching may not be noticed. Some sufferers show no signs
of infection, in which case it is a question of spotting the tiny white "thread-like" worms in motions.
Where do threadworms come from?
Threadworms spread by producing large numbers of tiny eggs. These eggs are so small they cannot be
seen with the naked eye. They are present in house dust; they stick to clothing, carpets, towels and
bedlinen; they can also be picked up from contact with someone who already has worms. Because the
eggs are so small and so widespread it is very easy for them to be swallowed.
When swallowed, the eggs pass into the bowel where they hatch into worms. When mature, the female
threadworm lays her eggs at night around the bottom, which causes the "itchy bottom". Scratching
allows transfer of eggs to the fingers and fingernails.
Eggs can then be easily transferred to the mouth by finger sucking or nail biting, causing reinfection,
and spread to other members of the family by direct contact.
Threadworms only affect humans, they do not affect pets.
How do I treat threadworms?
Threadworms are very easy to treat. Children do not need to be kept off school. Your pharmacist can
sell you suitable tablets or sachets for all the family. Since threadworms can spread so easily, it is
strongly recommend that all the family are treated at the same time.
Do I need to keep my children off school?
No, as long as the child is treated and the general hygiene measures outlined below are followed there is
no reason to keep a child off school.
How can I stop the problem coming back?
Threadworms are easily treated but unless the following precautions are taken the problem may recur.
Further Information: For the latest information on this condition and support or selfhelp Groups call the Health Information Service on 0800 665544
