What is the recommended treatment for a patient, regardless of age, diagnosed with pinworms (Enterobius vermicularis) infection?

Treatment of Pinworm Infection

For pinworm (Enterobius vermicularis) infection, treat with either mebendazole 100 mg or albendazole 400 mg as a single oral dose, repeated in 2 weeks, regardless of patient age. 1, 2, 3

First-Line Treatment Options

Both medications are equally effective and safe across all age groups:

• Mebendazole 100 mg: Single oral dose, repeated after 2 weeks 1, 3

  • The tablet may be chewed, swallowed, or crushed and mixed with food 3
  • Cure rate approximately 95% 3
  • Both adulticidal and ovicidal 4

• Albendazole 400 mg: Single oral dose, repeated after 2 weeks 1, 2

  • The same 400 mg dose applies to children of all ages, including toddlers 1
  • Both adulticidal and ovicidal 4

The repeat dose at 2 weeks is critical to eradicate newly hatched worms from eggs that survived the initial treatment, as the medications kill adult worms but may not eliminate all eggs 1, 2

Clinical Presentation to Recognize

• Nocturnal perianal itching is the hallmark symptom 1, 2, 4
• 30-40% of infected patients are completely asymptomatic 1, 4
• Additional symptoms may include weight loss, irritability, diarrhea, and abdominal pain 1, 2
• In girls, vaginal discharge may occur from female genital tract colonization 1, 2

Diagnostic Confirmation

• Cellophane tape test is the preferred diagnostic method 1, 2
  • Apply adhesive tape to perianal skin in the morning before bathing or defecation 2
  • Single test sensitivity is only ~50%, but increases to ~90% with three tests on different mornings 4
• Stool examination is NOT recommended, as pinworms and eggs are not usually passed in stool 1, 4

Critical Management Considerations

Household Treatment

• Treat all household members simultaneously, especially with multiple or repeated symptomatic infections, as reinfection is extremely common 4, 5
• Sexual partners should also be included in treatment 5

Treatment Failure vs. Reinfection

• True treatment failure is rare 1
• Persistent symptoms usually indicate reinfection rather than medication resistance 1
• Recurrences are common due to repeated cycles of autoinfection, given the short life span of adult pinworms 4

Monitoring for Extended Treatment

• If treatment extends beyond 14 days (not typical for pinworms but relevant for other helminthic infections), monitor for hepatotoxicity and leukopenia 1

Preventive Measures

Essential hygiene practices to prevent reinfection:

• Frequent handwashing, especially after bowel movements and before meals 4
• Clipping fingernails short 4
• Avoid finger-sucking, nail-biting, and scratching the anogenital area 4
• These measures are critical because even with effective medication, recurrences are common without proper hygiene 4

Special Populations

• Pregnant women: Pyrantel pamoate is preferred over mebendazole and albendazole 4
• All ages: The same standardized doses apply to both children and adults 1, 3

Common Pitfalls to Avoid

• Failing to repeat the dose at 2 weeks—this is not optional 1, 2
• Treating only the symptomatic patient without treating household contacts 4, 5
• Ordering stool examinations instead of the cellophane tape test 1, 4
• Assuming treatment failure when symptoms recur (usually reinfection) 1
• Neglecting hygiene education, which is essential for preventing the reinfection cycle 4