Human Lice

Pm 1156 | Revised | May 1998 There are three species of lice that can at times infest humans— the head louse, the body louse, and the crab or pubic louse. These pests belong to the group called sucking lice and, as their name implies, feed by sucking blood from a host. The feeding activity of these lice produces a considerable amount of personal discomfort and skin irritation that may cause itching, swelling, or the formation of various skin maladies. Additionally, continued scratching of infested areas may lead to secondary bacterial infection. Human lice infestations (called pediculosis) have become increasingly common over the past several years. These lice occur throughout the world. Contrary to popular belief, they may temporarily infest anyone, regardless of their level of cleanliness or economic status. Human lice occur almost exclusively on humans and are rarely, if ever, contracted from or passed to pets or other animals. Human lice infestations can be easily and effectively controlled. Infestations also can be prevented or minimized if individuals have a good understanding of the biology of these pests, their habits, and the methods that lead to their transmission.