What is the guidance for Enterobius vermicularis (pinworm) infection?

From the Guidelines

For pinworm infection, I strongly recommend albendazole 400 mg or mebendazole 100 mg, both as a single dose, as the most effective treatment option. This recommendation is based on the study by 1, which provides guidance on the investigation and initial management of pinworm infection. The study highlights the importance of proper diagnosis, which can be achieved through the 'sellotape test' performed by placing the sticky side of sellotape on the perianal skin and examining it under the microscope for ova.

Key points to consider in the management of pinworm infection include:

• The prepatent period of 2-4 weeks, during which the infection may not be symptomatic 1
• The worldwide distribution of the infection, particularly affecting children 1
• The mode of transmission through the faeco-oral route, emphasizing the importance of strict hand hygiene and proper sanitation 1
• The clinical presentation, which may include intense pruritis ani, weight loss, irritability, diarrhoea, abdominal pain, and occasionally colitis with eosinophilia 1

To prevent reinfection, it is essential to:

• Treat all household members simultaneously, even if asymptomatic
• Wash all bedding, underwear, and pajamas in hot water
• Vacuum living areas thoroughly
• Practice strict hand hygiene, including washing hands with soap and water after using the toilet and before eating
• Keep fingernails short and discourage nail-biting and scratching around the anus, as pinworms spread through eggs that are transferred from the anus to the mouth via contaminated hands, food, or surfaces 1

From the FDA Drug Label

Mebendazole tablets are indicated for the treatment of Enterobius vermicularis (pinworm), Trichuris trichiura (whipworm), Ascaris lumbricoides (common roundworm), Ancylostoma duodenale (common hookworm), Necator americanus (American hookworm) in single or mixed infections.

Adults, children 12 years of age and over, and children 2 years to under 12 years of age: Oral dosage is a single dose of 5 milligrams of pyrantel base per pound, or 11 milligrams per kilogram, of body weight not to exceed 1 gram.

When one individual in a household has pinworms, the entire household should be treated unless otherwise advised.

Guidance for Pinworm Treatment:

• The treatment options include mebendazole and pyrantel pamoate.
• Mebendazole has a cure rate of 95% for pinworm infection 2.
• Pyrantel pamoate is administered as a single dose, and the entire household should be treated if one individual has pinworms 3.
• It is essential to follow the recommended dosage and consult a physician if symptoms or pinworms are still present after treatment.

From the Research

Diagnosis of Pinworm Infestation

• The diagnosis of E. vermicularis infection is best established by the cellophane tape test, with a sensitivity of around 50% for a single test, increasing to approximately 90% with tests performed on three different mornings 4.
• If a worm is visualized in the perianal area or the stool, a pathological examination of the worm will yield a definitive diagnosis 4.
• Examination of the stool is not recommended as pinworms and eggs are not usually passed in the stool 4.

Treatment of Pinworm Infestation

• 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 given in a single dose and repeated in two weeks 4.
• Mebendazole and albendazole are both adulticidal and ovicidal, whereas pyrantel pamoate is only adulticidal 4.
• For pregnant women, pyrantel is preferred to mebendazole and albendazole 4.
• Treatment of all household members should be considered, especially if there are multiple or repeated symptomatic infections, as reinfection is common even with effective medication 4, 5.

Prevention of Pinworm Infestation

• Good personal hygiene, such as frequent handwashing, especially after bowel movements and before meals, is important in preventing pinworm infestation 4.
• Clipping of fingernails, avoidance of finger-sucking, nail-biting, and scratching in the anogenital area are also important preventive measures 4.
• Mass medication of affected groups can reduce symptoms rapidly, progressively, and in a cost-effective way 5.

Efficacy of Anthelmintic Drugs

• Single-dose oral albendazole, mebendazole, and pyrantel pamoate show high cure rates against A. lumbricoides, with cure rates of 88%, 95%, and 88%, respectively 6.
• For hookworm infection, albendazole was more efficacious than mebendazole and pyrantel pamoate, with cure rates of 72%, 15%, and 31%, respectively 6.
• Treatment of T. trichiura with single oral doses of current anthelminthics is unsatisfactory, with cure rates of 28% and 36% for albendazole and mebendazole, respectively 6.