Pinworm (Seatworm) Infection: Duration, Treatment, and Prevention

Pinworm (Enterobius vermicularis) is a common helminth infection, especially in children. The lifecycle perpetuates via fecal-oral autoinfection.

Timeline

• Adult worms: Live 4–8 weeks in cecum/appendix.
• Eggs: Deposited perianally at night → become infective in 4–6 hrs. Survive 2–3 weeks on surfaces (bedding, toys, dust).
• Symptoms: Perianal itching (nocturnal), sleep disturbance, irritability. Many asymptomatic.

Treatment

• Mebendazole 100 mg single dose (chewable) OR albendazole 400 mg single dose OR pyrantel pamoate 11 mg/kg (max 1 g).
• Repeat in 2 weeks to kill newly hatched worms (eggs not killed by meds).
• Treat entire household simultaneously.

Hygiene Measures (Critical for Eradication)

• Morning shower/bath (remove eggs); wash hands/nails thoroughly.
• Change underwear, pajamas, bedding daily; hot wash/dry.
• Vacuum carpets, damp-mop floors.
• Trim nails; discourage nail-biting, thumb-sucking.
• Disinfect toys, toilet seats.

Reinfection

Common if hygiene incomplete. If symptoms recur after 2 rounds, confirm diagnosis (scotch tape test), rule out other causes, consider extended treatment.

Pinworms are a nuisance, not dangerous. Persistence reflects environmental contamination, not drug failure.