Trying to keep ahead of lice: a therapeutic challenge.

Pediculosis capitis, or head lice, is a world-wide public health concern affecting persons of all ages and socioeconomic backgrounds. It is caused by Pediculus humanus capitis, an obligate ectoparasite that lives on human hair and feeds on the blood from the skin. Upon diagnosis, treatment should be initiated, since established infestations with head lice generally do not spontaneously resolve. Chemical pediculicides are currently the standard treatment, however, issues of resistance have made it necessary to explore new alternatives. If an infestation is resistant to these drugs, then the physician should consider treating with an agent from a different class of pediculicides or, potentially, with newer nonpediculicides.