Treatment of Pinworm Infection (Enterobius vermicularis)
The first-line treatment for pinworm infection is a single dose of mebendazole 100 mg, albendazole 400 mg, or pyrantel pamoate (11 mg/kg, maximum 1 g), with a repeat dose in 2 weeks to eradicate any newly hatched worms. 1, 2, 3, 4
Medication Options
- Mebendazole 100 mg as a single oral dose has a 95% cure rate for pinworm infections 2
- Albendazole 400 mg as a single oral dose is an effective alternative treatment 1, 4
- Pyrantel pamoate (11 mg/kg, maximum 1 g) is also effective, particularly in pregnant women where it is preferred over mebendazole and albendazole 3, 4
- All treatments should be repeated after 2 weeks to prevent reinfection from newly hatched eggs 1, 4
- Mebendazole and albendazole are both adulticidal and ovicidal, whereas pyrantel pamoate is only adulticidal 4
Treatment Considerations
- Treatment of all household members should be considered, especially with multiple or repeated symptomatic infections, as reinfection is common 4, 5
- For recurrent infections, prolonged treatment for up to 16 weeks using a "pulse scheme" may be recommended 5
- In cases of female genital tract colonization causing vaginal discharge, the same treatment regimen is effective 4, 6
Diagnostic Methods
- The cellophane tape test is the preferred diagnostic method for pinworm infection 1
- The sensitivity of a single test is around 50%, but increases to approximately 90% with tests performed on three different mornings 4
- Visual identification of worms in the perianal area or stool can provide definitive diagnosis 4
- Stool examination is not recommended as pinworms and eggs are not usually passed in the stool 4
Prevention of Reinfection
- Good personal hygiene is essential, including frequent handwashing, especially after bowel movements and before meals 4
- Clipping fingernails, avoiding finger-sucking, nail-biting, and scratching in the anogenital area are important preventive measures 4
- Changing and washing underwear, bedding, and nightclothes daily can help prevent reinfection 4, 5
- Treatment of all household members simultaneously is crucial for preventing reinfection 4, 5
Clinical Presentation
- Nocturnal perianal itching is the most common symptom of pinworm infection 1, 4
- Other symptoms may include weight loss, irritability, diarrhea, and abdominal pain 1
- Approximately 30-40% of infected patients are asymptomatic 4
- Female genital tract colonization may occur in girls, causing vaginal discharge 1, 6