Head lice shrug off shampoo: "Scientists have finally confirmed what parents and teachers have long suspected. Head lice have become impervious to the campaign to eradicate them. After randomly sampling almost 3000 schoolchildren in Wales, British scientists have concluded over-the-counter insecticidal shampoos to clear lice do little more than make the critters cleaner. Four out of five head lice collected during the research were found to be resistant to malathion, permethrin and phenothrin, the pesticides most commonly used in delousing treatments, according to a paper published in the British Medical Association journal Archives of Disease in Childhood. The findings did not surprise Australia's head lice expert, Richard Speare, of James Cook University. The last hope is a cocktail of herbal extracts and essential oils, with few clinical field trials to measure their efficacy and resistance potential. "A few herbal treatments such as Liceblaster, which rely on a whole range of compounds with active components, do work," Professor Speare said. "Instead of relying on a single chemical, the compounds work through a number of different pathways, so it is more difficult for the lice to become resistant." The alternative is the weekly white conditioner, he said, which thoroughly applied stun lice for 20 minutes, allowing easier removal with a nit comb."