Open Access

Head Lice

Head lice, Pediculus humanus capitis, have three development stages (egg, nymph, and adult) that range from around 0.5mm up to 3mm in length. The full life cycle, including development and reproductive stages, can be found in ‘ Figure 1: The life cycle of the head louse.’ Identification of an infestation can only be made by finding one or more live lice, usually whitish or grey-brown in color, on a person’s head or scalp. There are no clear symptoms and field studies have found that as many people without lice itch as those with lice, although in some cases itching is persistent and continuous. Limited evidence suggests that wet combing with conditioner may be the most sensitive diagnostic method, however, combing dry hair with a suitable plastic detection comb is quicker and nearly as good a technique for finding lice.

Top