CKS (2007) Threadworm. Clinical Knowledge Summaries. http://cks.nice.org.uk/threadworm#azTab Accessed 23.09.14. RATIONALE: There is only limited evidence regarding the two products licensed for the treatment of threadworm in the UK. Mebendazole is recommended first line based on expert opinion and its relatively better safety profile compared with piperazine. Piperazine is licensed only from 3 months of age,and although the BNF recommends off-label use of mebendazole for children aged 6 months and over, it does not recommend it for infants under 6 months of age. Expert opinion is that strict hygiene methods for 6 weeks can be used as an alternative treatment in those who cannot take mebendazole or piperazine. This is based on the life cycle of the threadworm (adults survive for about 6 weeks) and the long viability of eggs (up to 2 weeks).