Enterobiasis (Pinworm/Threadworm) caused by Enterobius vermicularis — most common helminth infection in school-age children worldwide.

Key features:

• Perianal/perineal pruritus at night (female migrates to perianal region at night to deposit eggs)
• Restless sleep, irritability
• Vaginal pruritus in girls (retrograde migration)
• Diagnosis: Scotch tape/adhesive tape test — applied perianally early morning before bathing or defecation → microscopy reveals ova

Treatment:

• Mebendazole 100 mg single dose OR Albendazole 400 mg single dose
• Repeat dose after 2 weeks (kills hatched worms from eggs not affected by first dose)
• Treat ALL household members simultaneously (highly contagious — fecal-oral + auto-inoculation)

Hygiene measures:

• Short fingernails, frequent handwashing
• Wash underwear/bedlinen in hot water
• Avoid nail-biting

Albendazole dosing in helminths: \(400\,\text{mg}\) single dose (Ascaris, hookworm, Enterobius); \(400\,\text{mg}\) daily × 3 days (Trichuris)