Threadworms
Threadworms are small, thread-like parasitic worms that live in the gut, most common in young children, and cause itching around the anus
About threadworms
Threadworm infection spreads through swallowing microscopic eggs, often picked up from contaminated hands, surfaces, food or bedding. Female worms lay eggs around the anus, usually at night, causing itching; scratching can transfer eggs to hands and surfaces, easily spreading the infection to others
Treatments
Symptoms
• Itching around the anus, especially at night
• Visible small, white, thread-like worms in stool or around the anus
• Disturbed sleep due to itching
• Irritability
• In girls, occasionally vaginal itching or discomfort
Diagnosis
Threadworms are usually diagnosed by seeing worms in stool or around the anus, sometimes confirmed with a simple sticky tape test to check for eggs under a microscope if unclear
Treatment
A single dose of an antiparasitic medicine (such as mebendazole) treats most cases, usually repeated after two weeks to catch any newly hatched worms. The whole household is usually treated at the same time, alongside strict hygiene measures, since eggs can survive on surfaces for weeks
Prevention and self-care
• Wash hands thoroughly, especially before eating and after using the toilet
• Keep fingernails short and discourage nail-biting
• Wash bedding, nightwear and towels on a hot wash after treatment
• Vacuum and damp-dust bedrooms
• Encourage showering rather than baths during treatment
• Treat all household members together to prevent reinfection
Reviewed by Hamza Iqbal Naheed, Superintendent Pharmacist, GPhC 2209194 (check the register) · Last updated 22 September 2026