Don't Be a Nit Wit; Know Your Lousy Companions!

Lice have been a burden on humans since antiquity. The species implicated in human infestations, the head louse (Pediculus humanus capitis), body louse (Pediculus humanus humanus), and pubic louse (Pthirus pubis), are very well adapted to the human host and are readily transmissible between and among individuals. In addition to dermal reactions and social stigmas associated with louse infestations, the body lice are of additional medical and public health concern in the spreading of bacterial agents associated with louse-borne relapsing fever, epidemic typhus, and trench fever. In the United States, pthiriasis, caused by P. pubis, is classified as a sexually transmitted infection. In this review, we provide an update on the taxonomy, epidemiology, biology, evolution, clinical importance, treatment and control, diagnosis, and reporting of parasitic human lice.