THREADWORM

Adult worms (white and a few mm long), live in the caecum. Females migrate to the anus to lay eggs, usually at night, causing night-time itching (pruritus ani). Threadworms are more common in school or pre-school children than in adults, but can affect whole families, especially in overcrowded conditions. Diagnose infection by applying adhesive tape to the anus; microscopy will reveal typical eggs. Treatment with an antihelmitic is available from pharmacies. Important to treat the whole family (even if asymptomatic) and follow stringent hygiene measures to ensure eradication. Exclusion from school of affected children is unnecessary.