Treatment of Pinworm (Enterobius vermicularis) Infection
The first-line treatment for pinworm infection is a single dose of mebendazole 100 mg or albendazole 400 mg, with a repeat dose in 2 weeks to eradicate any newly hatched worms. 1, 2, 3
Medication Options
- Mebendazole 100 mg as a single oral dose is FDA-approved for pinworm treatment with a 95% cure rate 2
- Albendazole 400 mg as a single oral dose is an effective alternative 4, 1, 3
- Pyrantel pamoate (11 mg/kg, maximum 1 g) is another option, particularly preferred during pregnancy 3
- All treatments should be repeated in 2 weeks to address the pinworm life cycle and prevent reinfection 1, 2, 3
Administration Considerations
- Mebendazole tablets may be chewed, swallowed, or crushed and mixed with food 2
- No special procedures such as fasting or purging are required 2
- Treatment of all household members should be considered, especially with multiple or repeated infections 3, 5
Clinical Presentation
- Nocturnal perianal itching is the most common symptom of pinworm infection 1, 3
- Other symptoms may include weight loss, irritability, diarrhea, and abdominal pain 1
- Female genital tract colonization may occur in girls, causing vaginal discharge 1, 6
- Approximately 30-40% of infected patients are asymptomatic 3
Diagnosis
- The cellophane tape test (perianal adhesive tape test) is the preferred diagnostic method 4, 3
- Single test sensitivity is around 50%, increasing to 90% when performed on three different mornings 3
- Direct visualization of worms in the perianal area provides definitive diagnosis 3
- Stool examination is not recommended as pinworms and eggs are not usually passed in stool 3
Prevention and Management of Recurrence
- Good personal hygiene is crucial, including frequent handwashing, especially after bowel movements and before meals 3
- Other preventive measures include:
Special Considerations
- For recurrent infections, prolonged treatment for up to 16 weeks using a "pulse scheme" may be recommended 5
- Pinworm infection is particularly common in children aged 5-14 years, with prevalence estimates of 20-30% worldwide 3, 5
- Ectopic infections can occur, with rare cases of vaginal enterobiasis that may serve as a reservoir for reinfection 6
Treatment Efficacy
- Mebendazole and albendazole are both adulticidal and ovicidal, while pyrantel pamoate is only adulticidal 3
- Success rates for approved antihelminthic agents are generally above 90% when properly administered 3, 5
- Despite effective treatment, recurrences are common due to repeated cycles of reinfection, particularly autoinfection 3