Head lice: Overview
This magnified picture of head lice on a fine-tooth comb shows that these bugs are tiny.
The medical name for head lice is Pediculus humanus capitis
Having head lice does not mean you are dirty. Most people get head lice when they have head-to-head contact with someone who has head lice. Head-to-head contact lets the lice crawl from one head to another head. The lice do not care whether the person has squeaky-clean hair or dirty hair. The lice are looking for human blood, which they need to survive.
Millions of people get head lice each year. Head-lice infestations are especially common in schools. In the United States, it is believed that about 6 to 12 million children between 3 and 12 years of age get head lice each year.
Head lice are not known to spread disease, but having head lice can make your scalp extremely itchy. If you scratch a lot, it can cause sores on the scalp that may lead to an infection. Some people lose sleep because the itch is so intense.
Treatment, which most people can do at home, usually gets rid of head lice. If you have trouble getting rid of the lice or have an infection from scratching, you should see a dermatologist.
Related AAD resources
Burkhart CN, Burkhart CG. “Fomite transmission in head lice.” J Am Acad Dermatol 2007; 56(6):1044-1047.
Canyon, DV, Speare R, et al. “Spatial and kinetic factors for the transfer of head lice (Pediculus capitis) between hairs.” J Invest Dermatol 2002; 119(3):629-631.
Frankowski BL, Bocchini JA. “Head Lice.” Pediatrics. 2010; 126(2):392-403.
Jacobson CC, Abel EA. “Parasitic infestations.” J Am Acad Dermatol 2007; 56(6):1026-1043.
Ko CJ, Elston DM. “Pediculosis.” J Am Acad Dermatol 2004; 50(1):1-12.