title: Insecticide resistance in head lice: clinical, parasitological and genetic aspects.
abstract: Insecticide treatment resistance is considered to be a major factor in the increasing number of infestations by head lice. The large insecticide selection pressure induced by conventional topical pediculicides has led to the emergence and spread of resistance in many parts of the world. Possible mechanisms of resistance include accelerated detoxification of insecticides by enzyme-mediated reduction, esterification, oxidation that may be overcome by synergistic agents such as piperonyl butoxide, alteration of the binding site, e.g. altered acetylcholinesterase or altered nerve voltage-gated sodium channel, and knockdown resistance (kdr). Clinical, parasitological and molecular data on resistance to conventional topical pediculicides show that treatments with neurotoxic insecticides have suffered considerable loss of activity worldwide. In particular, resistance to synthetic pyrethroids has become prominent, probably because of their extensive use. As other treatment options, including non-insecticidal pediculicides such as dimeticone, are now available, the use of older insecticides, such as lindane and carbaryl, should be minimized, owing to their loss of efficacy and safety concerns. The organophosphorus insecticide malathion remains effective, except in the UK, mostly in formulations that include terpineol.
authors.affiliation: Department of Parasitology and Mycology, Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne, Bobigny, Cedex, France. remy.durand@avc.aphp.fr
authors.forename: R
authors.initials: R
authors.lastname: Durand
authors.forename: S
authors.initials: S
authors.lastname: Bouvresse
authors.forename: Z
authors.initials: Z
authors.lastname: Berdjane
authors.forename: A
authors.initials: A
authors.lastname: Izri
authors.forename: O
authors.initials: O
authors.lastname: Chosidow
authors.forename: J M
authors.initials: JM
authors.lastname: Clark
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry; D000818:Animals; D012721:Carbaryl / Q000009:adverse effects / Q000494:pharmacology; D002626:Chemistry, Pharmaceutical; D017344:Genes, Insect; D006203:Hair Preparations / Q000009:adverse effects / Q000494:pharmacology; D001556:Hexachlorocyclohexane / Q000009:adverse effects / Q000494:pharmacology; D006801:Humans; D007305:Insecticide Resistance; D007306:Insecticides / Q000009:adverse effects / Q000494:pharmacology*; D010373:Lice Infestations / Q000188:drug therapy / Q000469:parasitology* / Q000473:pathology; D008294:Malathion / Q000009:adverse effects / Q000494:pharmacology; D010374:Pediculus / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D026023:Permethrin / Q000009:adverse effects / Q000494:pharmacology; D055553:Prescription Drugs / Q000009:adverse effects / Q000494:pharmacology
chemical_list: D006203:Hair Preparations; D007306:Insecticides; D055553:Prescription Drugs; D026023:Permethrin; D001556:Hexachlorocyclohexane; D000110:Acetylcholinesterase; D012721:Carbaryl; D008294:Malathion