Pinworm test

When a person has a pinworm infection, adult pinworms live in the intestine and colon. At night, the female adult worms deposit their eggs outside the rectum near the anal area.

One way to detect pinworms is to shine a flashlight on the anal area. The worms are tiny, white, and threadlike. If none are seen, check for 2 or 3 additional nights.

The best way to diagnose this infection is to do a tape test. The best time to do this is in the morning before bathing, because pinworms lay their eggs at night.

Steps for the test are:

• Firmly press the sticky side of a 1-inch (2.5 centimeters) strip of cellophane tape over the anal area for a few seconds. The eggs stick to the tape.
• The tape is then transferred to a glass slide, sticky side down. Put the piece of tape in a plastic bag and seal the bag.
• Wash your hands well.
• Take the bag to your health care provider. The provider will check the tape to see if there are eggs.

The tape test may need to be done on 3 separate days to improve the chances of detecting the eggs.

You may be given a special pinworm test kit. If so, follow instructions on how to use it.

No special preparation is necessary.

The skin around the anus may have minor irritation from the tape.

This test is performed to check for pinworms, which can cause itching in the anal area.

If adult pinworms or eggs are found, the person has a pinworm infection. Usually, all household members need to be treated with medicine. This is because pinworms are easily passed back and forth within a household.

There are no risks with this test.

Oxyuriasis test; Enterobiasis test; Tape test

Dent AE, Kazura JW. Enterobiasis (Enterobius vermicularis). In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 320.

Mejia R, Weatherhead J, Hotez PJ. Intestinal nematodes (roundworms). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 286.

Updated by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.