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Head lice - Management
Basis for recommendation
The recommended strategy for dealing with recurrent head lice or persistence of head lice after treatment is based on expert opinion [PHMEG, 2008].
- There is limited evidence to support the effectiveness of each treatment option and there are advantages and disadvantages to all methods. No option is clearly superior or inferior to the others, and none can guarantee success. The choice of a particular treatment strategy will depend on individual or parent preference.
- Since no treatment for head lice is completely ovicidal, it is possible that an egg laid on the morning of the first treatment could survive treatment and hatch a live head louse after the completion of a course of treatment [Lebwohl et al, 2007]. The average time from lay to hatch is 7 days, but longer intervals of up to 12 days between lay and hatch have been observed in laboratory studies.
- Reinfestation is also a common cause of perceived treatment failure [PHMEG, 2008].
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