How to manage head lice

How to manage head licePeople are infested by 3 types of lice: body lice (Pediculus humanus var corporis), head lice (P h var capitis), and crab or pubic lice (Phthirus pubis).Lice have evolved with their human hosts and have developed life cycles and anatomy best suited to those particular areas of the body. 1 Body lice are associated with severe systemic diseases such as typhus and trench fever.Infestation with crab lice most commonly follows intimate or sexual contact. 2 Of the 3 lice types, head lice get the most attention because they are thought to be highly prevalent and to be developing resistance to commonly used pediculicides.The treatment of head lice is a multimillion dollar industry. 3In this review, we look at this treatment. THE EXTENT OF THE PROBLEMThe Centers for Disease Control and Prevention (CDC) report that 6 to 12 million people in the United States are infested each year with head lice. 4 Children aged 3 to 10 years in preschool and elementary school are most likely to have infestations.Girls have an increased risk because of more frequent head-to-head contact.African Americans have fewer reported infestations compared with other ethnic groups, which may be due to differences in hair thickness and curl.Head lice are found across all socioeconomic classes. THE LIFE OF A HEAD LOUSEHead lice are thought to be transmitted mainly through head-to-head contact.Fomites-clothing and other articles that transmit disease, such as combs, hats, helmets, bedding, and other personal items-have been implicated in their transmission, although this is not universally accepted. 1,5ead lice are obligate ectoparasites that live on human skin and can survive only on human blood; they do not infest other animals. 1 They need several meals of blood each day and die if away from the host head for more than 2 days. 1 They are wingless and cannot jump but climb quickly from hair to hair when the hair is dry.When the hair is wet, lice hardly move, making them vulnerable for identification and removal by gloved hands or with the aid of a specially designed fine-tooth comb. 6he adult female louse firmly attaches 7 to 10 eggs a day to human hair using a gluelike, water-insoluble substance.These eggs are deposited close (1 mm) to the scalp so that the heat and moisture from the host's head incubates the egg. 5 Eggs laid farther away from the scalp are not likely to be viable.They are most commonly found in the occipital and postauricular regions, but may be found anywhere on the head.By 7 to 10 days, when the nymph emerges from the egg, it is close enough (within 6 mm) to the scalp to easily have its first meal of blood.The distance