Pinworms – infection and treatment

Pinworms are light-coloured fusiform parasites that are approximately 3 to 13 mm long and live in the intestines of humans. Pinworms are mostly detected in children aged between 4 and 15, but an infection might spread to adults too.

How do you get pinworms?

An infection occurs when the eggs of a pinworm are swollen. The eggs are so small that they are not visible to the eye. In the night, female pinworms lay eggs in the anal region, and the eggs are spread between people through hand contact or coming in contact with the same bedclothes, toys or door handles, for example. The life span of individual pinworms is only a month, but once you are infected, it is easy to become infected again.

Incubation period: Symptoms manifest approximately 5–6 weeks after an infection.

Symptoms: Minor pinworm infections are asymptomatic. If there are plenty of pinworms, the primary symptom is the itching of the anus, especially at night.

How to get rid of pinworms?

Prescription-free pinworm medications are available in pharmacies. The eradication of a pinworm infection should be performed on all members of the family at the same time in order to treat the asymptomatic carriers of the infection too. The treatment must be performed again two weeks after the first round of treatment in order to break the infection cycle. Bedclothes and underwear should be washed in warm water on the day after the medication is taken. Basic house cleaning should also be performed, including vacuuming the mattresses, blankets and pillows and cleaning all surfaces carefully, especially the surfaces of the bathroom (toilet, taps, door handles).

When should you see a doctor?

You should see a doctor if the symptoms persist even after carefully performed eradication treatment. Prescription medications are also available. Remember that help is always available in the Digital Clinic every day! The service can be accessed through the OmaMehiläinen mobile application or online Service.

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How can pinworm infections be avoided?

Pinworm infections can be prevented by not allowing the eggs access your intestines through your mouth. Always wash your hands after going to the toilet and before eating. Clip your fingernails short so that there is no room for eggs. If there is a pinworm infection in your home, please inform the daycare centre or school of your children. If there are several cases of pinworm infection in the class or daycare group, the entire group can be treated simultaneously.

Text: M.D., Paediatrician Maria Enlund-Cerello

Sources: The National Institute for Health and Welfare, Duodecim Health Library

Specialists and locations

Minna Aaltonen
LT, lastentautien erikoislääkäri
Henrikka Aito
LT, lastentautien erikoislääkäri
Minna Aromaa
LT, lastentautien erikoislääkäri
Justin Bejedi
LL, lastentautien erikoislääkäri