A 5-year-old with pruritus around the perianal area tests positive with cellophane tape. What is the treatment of choice?

• A. Mebendazole (Vermox)
• B. Metronidazole (Flagyl)
• C. Chloroquine (Aralen)
• D. Paromomycin (Humantin)

Answer: (A)

Pinworm infection presents with perianal itching and is diagnosed by the cellophane tape test, which detects Enterobius vermicularis eggs. The treatment of choice in a child is mebendazole because it effectively kills pinworms by inhibiting microtubule formation in the worms, leading to their immobilization and death. The standard approach is a single dose now, with a second dose in about two weeks to eliminate any newly hatched larvae, plus treating all household contacts since transmission is common. Emphasize hygiene measures to prevent reinfection, such as handwashing, daily diaper or bath routines, and washing bedding and underwear. The other medications listed aren’t used for pinworms—metronidazole targets protozoa and anaerobes, chloroquine treats malaria, and paromomycin is used for other intestinal parasites but not the preferred therapy for pinworm.