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Pinworm test

Definition

A pinworm test is a method used to identify a pinworm infection. Pinworms are small, thin worms that commonly infect young children, although anyone can be infected.

Alternative Names

Oxyuriasis test; Enterobiasis test; Tape test

How the Test is Performed

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.

How to Prepare for the Test

No special preparation is necessary.

How the Test will Feel

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

Why the Test is Performed

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

What Abnormal Results Mean

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.

Risks

There are no risks with this test.

Considerations


Gallery

Pinworm eggs
Pinworms are a common problem in children and may spread to adults (typically the parents or other care-givers). The eggs may be easily seen under a microscope. To obtain a sample, a piece of cellophane tape is pressed against the patient's anal opening. The sticky side of the tape picks up the pinworm eggs and the tape is then stuck to a microscope slide. The eggs can be viewed under the microscope, as seen above. (Image courtesy of the Centers for Disease Control and Prevention.)
Pinworm eggs
Pinworms are a common problem in children and may spread to adults (typically the parents or other care-givers). The eggs may be easily seen under a microscope. To obtain a sample, a piece of cellophane tape is pressed against the patient's anal opening. The sticky side of the tape picks up the pinworm eggs and the tape is then stuck to a microscope slide. The eggs can be viewed under the microscope, as seen above. (Image courtesy of the Centers for Disease Control and Prevention.)
Pinworm eggs
Pinworms are a common problem in children and may spread to adults (typically the parents or other care-givers). The eggs may be easily seen under a microscope. To obtain a sample, a piece of cellophane tape is pressed against the patient's anal opening. The sticky side of the tape picks up the pinworm eggs and the tape is then stuck to a microscope slide. The eggs can be viewed under the microscope, as seen above. (Image courtesy of the Centers for Disease Control and Prevention.)

References

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.

Last reviewed September 10, 2022 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..

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