Head lice and their control: A never-ending story...

Abstract

This chapter deals with the life cycle of human head lice (Pediculus humanus capitis), their history, their medical importance and their social relevance. It also takes an in-depth look at the different methods of lice control. Although head lice were and are still neglected in communities of many regions in the world (apparently due to their obvious low activity as vectors of diseases), their appearance in societies with high hygiene standards often causes hysterical reactions among people using disproportionate and often health-threatening remedies for their control. This chapter tries to convey rational information on the action needed in case of a lice-outbreak in a family and/or in other social groups (kindergarten, school, hospital, etc.). It also describes important movements within the market for anti-lice products. While there are increasing mutation-derived resistances of the lice to several pharmacologically-acting insecticides such as permethrin, malathion, lindane, etc., suffocating products are progressing worldwide. These medicinal products are based either on chemical compounds such as di- and/or cyclomethicones or on plant extracts. Some of these products, however, pose health problems due to their inflammability and/or due to toxic effects in case of intensive long-term skin contact or in case of consumption or inhalation. Since none of the products protects longer than a few hours against a new lice infestation, it is important that anti-lice treatment is carried out simultaneously in a group of people after a lice outbreak.