Treatment of Pinworms (Enterobiasis)
The recommended treatment for pinworm infection is either albendazole 400 mg or mebendazole 100 mg as a single oral dose, with a mandatory repeat dose in 2 weeks to eradicate newly hatched worms. 1
First-Line Medication Options
Both medications are equally effective and safe across all age groups:
- Albendazole 400 mg: Single oral dose, repeated in 2 weeks 1
- Mebendazole 100 mg: Single oral dose, repeated in 2 weeks 1, 2
The dosing is standardized—the same dose applies to both children (including those as young as 2 years old) and adults. 1 The FDA confirms mebendazole achieves a 95% cure rate for pinworm infection. 2
Critical Treatment Principles
The Two-Dose Requirement
The second dose at 2 weeks is not optional—it is essential. 1 This timing targets newly hatched worms from eggs that survived the initial treatment, breaking the reinfection cycle. Treatment failure is rare; persistent symptoms almost always indicate reinfection rather than medication resistance. 1
Household Treatment Strategy
Treat all household members simultaneously, especially when there are multiple or repeated symptomatic infections. 3 Reinfection is extremely common even with effective medication due to the ease of transmission within households. 3, 4
Medication Selection
Both albendazole and mebendazole are adulticidal (kill adult worms) and ovicidal (kill eggs), making them superior to alternatives. 3 The choice between them is based primarily on availability and patient preference, as efficacy is equivalent. 1
Special Populations
- Pregnant women: Pyrantel pamoate is preferred over albendazole or mebendazole 3
- Children ≥2 years: Standard adult dosing applies 1
Safety Monitoring
For standard pinworm treatment (single dose repeated once), no special monitoring is required. 1 However, if treatment extends beyond 14 days (rare, only for complicated cases), monitor for hepatotoxicity and leukopenia. 1
Common Pitfalls to Avoid
Inadequate Hygiene Measures
Medication alone is insufficient. Implement these measures concurrently:
- Frequent handwashing, especially after bowel movements and before meals 3
- Clip fingernails short to reduce egg accumulation 3
- Avoid finger-sucking, nail-biting, and scratching the perianal area 3
- Daily morning bathing to remove eggs deposited overnight 4
Forgetting the Second Dose
The most common treatment failure occurs when patients skip the 2-week repeat dose. 1 Emphasize this requirement explicitly to patients and caregivers.
Treating Only the Symptomatic Individual
Remember that 30-40% of infected individuals are asymptomatic. 1 Treating only the symptomatic person while leaving asymptomatic household members untreated perpetuates the cycle of reinfection. 3
Clinical Presentation Recognition
The hallmark symptom is nocturnal perianal itching. 1 Other manifestations include:
- Weight loss, irritability, diarrhea, abdominal pain 1
- In girls: vaginal discharge from female genital tract colonization 1
- 30-40% of infected children remain completely asymptomatic 1
Diagnostic Confirmation (When Needed)
The cellophane tape test is the diagnostic standard: apply the sticky side of tape to the perianal skin in the morning before bathing or defecation. 1 A single test has only 50% sensitivity, but three tests performed on different mornings increase sensitivity to approximately 90%. 3 Stool examination is not useful since pinworms and eggs are rarely passed in stool. 1
Recurrence Management
If symptoms persist after completing the two-dose regimen, this almost always represents reinfection rather than treatment failure. 1 Reassess household hygiene measures and ensure all household members were treated. Consider retreatment of the entire household with the same regimen. 3, 4