Pinworms, also known as Enterobius vermicularis, are the most common cause of worm infections in the United States. They often infect school-aged children and are easily transmitted between people who live in the same household.
The life cycle of pinworms begins with eggs being deposited around the anus, which results in itching in the area that is worse at night. Self-infection occurs when the child itches the area and transfers the eggs into the mouth with contaminated hands. This is also how it is transmitted from person to person, when contaminated hands touch food, linens, or household surfaces.
The most common symptom indicating a pinworm infection is anal itching, but sometimes there may be no symptoms at all. More severe infections may result in abdominal pain, nausea, and vomiting. Diagnoses are often made clinically based on the symptoms, but there are some tests that a doctors office can perform to confirm. The scotch tape test involves pressing tape against the anal region and inspecting under the microscope for the presence of eggs. The paddle test is also used, where a small paddle with an adhesive coating is used instead of tape. Usually the best samples are taken first thing in the morning prior to showering.
After a pinworm infection is confirmed, there are many measures that should be taken for treatment and prevention of spread. Pyrantel is an antiparasitic medication that is available over the counter. Albendazole and mebendazole are also antiparasitics that are very effective but need to be prescribed. To prevent spread and re-infection, it is important to frequently wash hands and clean all linens thoroughly. It is also recommended to treat all members of the household, because the pinworm can incubate for 1-2 months after infection before any symptoms arise.