Pinworm (Enterobius Vermicularis) Infestation: An Updated Review

Pinworm infestation is an important public health problem worldwide, especially among children 5 to 10 years of age in developing countries with temperate climates. The problem is often overlooked because of its mild or asymptomatic clinical manifestations.

The purpose of this article was to familiarize pediatricians with the diagnosis and management of pinworm infestation.

A search was conducted in August 2023 in PubMed Clinical Queries using the key terms "Enterobius vermicularis," OR "enterobiasis," OR "pinworm." The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

Enterobiasis is a cosmopolitan parasitosis caused by Enterobius vermicularis. It affects approximately 30% of children worldwide and up to 60% of children in some developing countries. Predisposing factors include poor socioeconomic conditions, inadequate sanitation, poor personal hygiene, and overcrowding. Children aged 5 to 14 years have shown the highest prevalence of enterobiasis.. Egg transmission is mainly by the fecal-oral route. Approximately 30 to 40% of infested patients do not show any clinical symptoms of the disease. For symptomatic patients, the most common presenting symptom is nocturnal pruritus ani. The diagnosis of E. vermicularis infection is best established by the cellophane tape test. The sensitivity of one single test is around 50%; however, the sensitivity increases to approximately 90% with tests performed on three different mornings. If a worm is visualized in the perianal area or the stool, a pathological examination of the worm will yield a definitive diagnosis. As pinworms and eggs are not usually passed in the stool, examination of the stool is not recommended. The drugs of choice for the treatment of pinworm infestation are mebendazole (100 mg), pyrantel pamoate (11 mg/kg, maximum 1 g), and albendazole (400 mg), all of the above-mentioned drugs are given in a single dose and repeated in two weeks. Mebendazole and albendazole are both adulticidal and ovicidal, whereas pyrantel pamoate is only adulticidal. Given their safety and effectiveness, mebendazole and albendazole are currently the best available drugs for the treatment of pinworm infestation. For pregnant women, pyrantel is preferred to mebendazole and albendazole. Treatment of all household members should be considered, especially if there are multiple or repeated symptomatic infections because reinfection is common even when effective medication is given.

In spite of effective treatment of pinworm infestation, recurrences are common. Recurrences are likely due to repeated cycles of reinfection (particularly, autoinfection) because of the short life span of adult pinworms. Good personal hygiene, such as frequent handwashing, especially after bowel movements and before meals, clipping of fingernails, avoidance of finger-sucking, nail-biting, and scratching in the anogenital area, are important preventive measures. Treatment of all household members should be considered, especially if there are multiple or repeated symptomatic infections.