Lice are parasitic insects that can be found on people's heads, and bodies, including the pubic area. Human lice survive by feeding on human blood. Lice found on each area of the body are different from each other. The three types of lice that live on humans are:
Pediculus Humanus capitis (head lice)
Pediculus humanus corporis (body lice)
Pthirus pubis (pubic lice, or “crabs”)
Adult head lice are approximately 2-3mm in length and appear brown in color. Lice eggs, also called nits, are approximately 1mm in length and appear brown or off-white in color. Brown colored nits still contain a bug and white colored nits are empty shells. Lice tend to live and lay their eggs within ½ inch of the scalp. Eggs are attached to the hair with a strong, gluelike, non-water soluble, substance.
The lice cycle of a louse is about 30 days. Lice begin reproducing 7-10 days after they are born and lay 5-8 eggs a day. In their lifetimes, a female can lay over 100 eggs. Each egg contains one premature louse, often referred to as a nymph. A nymph is very small and often goes undetected in visual examinations. Lice infestations are most commonly detected by the discovery of eggs in the person’s hair after experience itching. Head lice are not known to spread disease.
Lice will die of starvation within 1-2 days of separation from a human host. They are reliant on warmth of the human scalp for their own survival and the incubation of their eggs. They do not usually leave the head unless attempting to transfer to a new host.
Adult body lice are approximately 2.5-3.5mm in length. Body lice live and lay eggs on clothing and only move to the skin to feed.
Body lice are known to spread disease.
Body lice infestations are spread most commonly by close person-to-person contact but is generally limited to persons who live under conditions of crowding and poor hygiene (for example., homeless, refugees, etc.). Dogs, cats, and other pets do not play a role in the transmission of human lice. Improved hygiene and access to regular changes of clean clothes is the only treatment needed for body lice.
Prevention & Control
Body lice are spread most commonly by direct contact with an infested person or an infested person’s clothing or bedding. Body Lice usually infest persons who do not change launder and change their clothes regularly. The following are steps that can be taken to help prevent and control the spread of body lice:
Bathe regularly and change into properly laundered clothes at least once a week; launder infested clothing at least once a week.
Machine wash and dry infested clothing and bedding using the hot water (at least 130°F) laundry cycle and the high heat drying cycle. Clothing and items that are not washable can be dry-cleaned OR sealed in a plastic bag and stored for 2 weeks.
Do not share clothing, beds, bedding, and towels used an infested person.
Fumigation or dusting with chemical insecticides sometimes is necessary to control and prevent the spread by body lice of certain diseases (epidemic typhus). Nit Control does not offer treatment for body lice.
Pubic "Crab" Lice
Adult pubic lice are 1.1-1.8 mm in length. Pubic lice typically are found attached to hair in the pubic area but sometimes are found on coarse hair elsewhere on the body (for example, eyebrows, eyelashes, beard, mustache, chest, armpits, etc.).
Pubic lice infestations (pthiriasis, pronounced THIR-i-a-sus) are usually spread through sexual contact. Dogs, cats, and other pets do not play a role in the transmission of human lice.
Both over-the-counter and prescription medications are available for treatment of pubic lice infestations. Nit Control does not offer treatment for pubic lice.
Body Lice. Centers for Disease Control and Prevention 5-16-08