What is the recommended dosage of mebendazole (antiparasitic medication) or albendazole (antiparasitic medication) for a 2-year-old child with a pinworm infection?

Pinworm Treatment Dosage for a 2-Year-Old

For a 2-year-old child with pinworm infection, give either albendazole 400 mg OR mebendazole 100 mg as a single oral dose, with a repeat dose in 2 weeks. 1, 2

Medication Options

Both medications are equally effective and safe for treating pinworm (Enterobius vermicularis) in young children:

• Albendazole 400 mg as a single oral dose 1, 3, 2
• Mebendazole 100 mg as a single oral dose 1, 2

The repeat dose at 2 weeks is essential to eradicate any newly hatched worms from eggs that survived the initial treatment, as both medications are adulticidal and ovicidal but eggs may still be present in the environment. 2, 4

Important Clinical Considerations

Age-Appropriate Dosing

• The 400 mg dose of albendazole is the standard adult dose and applies to children of all ages for pinworm treatment, including 2-year-olds. 1, 3, 2
• The 100 mg dose of mebendazole is similarly standardized across age groups for pinworm. 1, 2

Treatment of Household Contacts

• Treat all household members simultaneously, especially if there are multiple or repeated symptomatic infections, as reinfection is extremely common even with effective medication. 4
• Pinworm transmission occurs via the fecal-oral route, and eggs can survive in the household environment, making family-wide treatment critical. 1, 4

Common Pitfalls to Avoid

Diagnostic Approach

• If diagnosis confirmation is needed, use the cellophane tape test (sticky side of tape applied to perianal skin in the morning before bathing), as pinworms and eggs are not usually passed in stool. 1, 2, 4
• A single tape test has only 50% sensitivity, but three tests performed on different mornings increase sensitivity to approximately 90%. 4

Preventing Reinfection

• Emphasize good hand hygiene, especially after bowel movements and before meals. 4
• Clip fingernails short and discourage nail-biting, finger-sucking, and scratching the anogenital area to prevent autoinfection. 4
• Recurrences are common due to the short life span of adult pinworms and repeated cycles of reinfection/autoinfection, not treatment failure. 4

Clinical Presentation

• The most common symptom is nocturnal perianal itching, though 30-40% of infected children are asymptomatic. 1, 2, 4
• Other symptoms may include weight loss, irritability, diarrhea, abdominal pain, and in girls, vaginal discharge from female genital tract colonization. 1, 2, 4