Head lice are the Pediculus humanus capitis parasite, which causes infestations of the scalp, most commonly in school aged children. Head lice are commonly known as nits, however nits are egg shells that have hatched or contain unviable embryos and not the lice themselves.
Head lice are spread by close contact with someone that has head lice, usually in schools or amongst family members. Transmission is by head to head contact or by sharing equipment like combs or towels.
Infestation causes an itchy scalp. Often the nits (eggs) and even lice themselves are visible when examining the scalp.
Dimeticone 4% lotion can be applied to the hair and left to dry. This is left on for 8 hours (i.e. overnight), then washed off. This process is repeated 7 days later to kill any head lice that have hatched since treatment.
Special fine combs can be used to systematically comb the nits and lice out of the hair. They can be used for detection combing to check the success of treatment. NICE clinical knowledge summaries recommend The Bug Buster kit.
Last updated January 2020