Head lice are a global problem affecting all strata of society. Although there is no systematic study of prevalence rates, it has been estimated that the prevalence ranges from 0.7% to 76%, and children aged three to 11 years are the most susceptible. Girls are twice as likely as boys to be infested. Although the cause for this high rate is unclear, researchers believe that social behaviours may play a role in the outbreak.
A number of developed countries have published guidelines for the treatment of head lice, based on research. These guidelines are intended to provide general guidance to many sectors of society, but they recognize that local data is important in understanding patterns of insecticide resistance and developing local recommendations that take into account local cultural factors.
While there are many different ways to treat the infestation, head lice is primarily transmitted through direct contact with another individual. The most common means of transmission involve head-to-head contact and social contacts, particularly between parents and children. The school environment is also a valuable resource in the transmission of pediculosis. The number of children per family, socioeconomic status, and school environment all contribute to the risk of infection.
The majority of people affected by head lice do not show any symptoms, but they can tell whether their child has head lice by examining the condition with a special lice comb. In addition, a child with head lice should avoid sharing hats or other grooming aids with other children.