What Are Pinworms?

The parasitic worms can cause an itchy infection.

Pinworms are one of a number of parasitic worms that can infect the human body. Itching in the anal area is the most common indication of a pinworm infection. Pinworm eggs can be can spread directly or indirectly.

Anyone can develop a pinworm infection, though populations like young children may be more at risk. However, treatment options are available to help resolve any infections, and infections are preventable.

Pinworm Symptoms

The primary symptom of a pinworm infection is anal itching, or anal pruritus. The itching can also result in difficulty sleeping, irritability, and restlessness. However, a person can potentially have no symptoms.

How Pinworms Spread

Pinworm infection is caused by a white roundworm with the scientific name Enterobius vermicularis. A pinworm infection is the most common type of intestinal worm infection in the US.

People catch these parasites by accidentally swallowing their eggs. If a person who has pinworm eggs touches their anus, the eggs can stick to their fingers. The eggs can be spread by hand contact or through contaminated food or articles, such as bedding or clothing.

Once the eggs hatch, the pinworms make themselves at home in the colon and rectum. Female pinworms eventually lay eggs on the skin around the anus while a person sleeps.

Risk Factors

Pinworms can affect anyone of any age. However, the following individuals are most at risk:

  • Institutionalized individuals
  • People living with or taking care of others with a pinworm infection
  • Preschool-aged and school-aged children

How Are Pinworm Infections Diagnosed?

Diagnosis of a pinworm infection may include a cellophane tape or pinworm paddle test. Adhesive material, much like tape, is applied around the anal area. A healthcare provider examines the tape under a microscope to determine the presence of eggs or worms.

How To Treat Pinworms

Mild pinworm infections may not require treatment. When treatment is necessary though, the entire household must take the treatment. Treating everyone avoids reinfection.

Medication is the main way to treat pinworm infections. Typical medications used include albendazole, mebendazole, or pyrantel pamoate. Pyrantel pamoate is available as an over-the-counter (OTC) medication, while the other two options require a prescription.

You have to take two doses of the medicines. You may be given any of these medications for your first dose and need to take another dose of the same one two weeks later.

Note: The medication used to treat pinworms is not effective on pinworm eggs. A second treatment is required about two months after the first treatment to destroy newly hatched worms.


There are ways to prevent pinworm infections. Ways to avoid infection or reinfection include:

  • Avoiding nail-biting
  • Changing your underwear daily
  • Not scratching your anus
  • Showering or bathing each morning
  • Regularly washing your sheets and pajamas
  • Washing your hands after diaper changes and bathroom visits


Some complications due to pinworms can include abdominal pain and appendicitis. These complications may be a result of pinworms causing inflammation surrounding the appendix or blocking the inside of the appendix.

Other complications may be:

  • Surface-based bacterial infections from scratching the anus
  • Urinary tract infections (UTIs)
  • Vulvovaginitis, a condition where the vagina or vulva is inflamed or irritated

Living with Pinworms

The prognosis after a pinworm infection is good with treatment adherence and completion. Recurrences can happen, but ensuring you get and follow up with treatment can make the infections go away again.

A Quick Review

Tiny worms called pinworms can cause intense anal itching and lead to potential irritability and problems with sleep. Pinworm infections can affect anyone. However, certain groups are more at risk for developing the infections, like people caring for others with pinworm infections. The primary treatment is medication, taken in two-week intervals. Prevention entails good hygiene practices, such as proper handwashing and daily morning showering.

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4 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Pinworms.

  2. Centers for Disease Control and Prevention. About pinworm infection.

  3. Rawla P, Sharma S. Enterobius vermicularis. In: StatPearls. StatPearls Publishing; 2023.

  4. Centers for Disease Control and Prevention. Parasites - Enterobiasis (also known as pinworm infection) - treatment.

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