Pubic ("crab") lice infestation is found worldwide and occurs in all races and ethnic groups and in all levels of society. Pubic lice usually are spread through sexual contact and are most common in adults. Occasionally pubic lice may be spread by close personal contact or contact with articles such as clothing, bed linens, and towels that have been used by an infested person. Pubic lice found on the head or eyelashes of children may be an indication of sexual exposure or abuse.

Pubic lice do not transmit disease; however, secondary bacterial infection can occur from scratching of the skin.