What are human body lice?
Body lice are small insects that live on clothing or bedding of humans and feed on human blood. Homeless individuals who cannot wash clothing or bedding at least once a week or take a bath or shower regularly are at risk for getting body lice.
How are body lice different from head and pubic lice?
Body lice and head lice look very similar. Head lice are slightly smaller than body lice. Head lice are found only on the head whereas body lice are found on the clothing or on parts of the body other than the head. Body lice spend most of their time on the clothing of an infested person, visiting the body several times a day to feed. The eggs (called nits) of body lice are cemented to clothing fibers and seams or, occasionally, to body hairs. Head lice, however, live in people’s hair and glue their eggs directly to hair near the scalp. Pubic lice have a different shape than head and body lice. Pubic lice are round and have a crab-like appearance. Pubic lice are usually found in pubic hair, but may occasionally be found on other coarse body hair such as armpit, chest, and facial hair.
What do body lice look like?
The body louse has three life stages: the egg (nit), the nymph, and the adult. Nits are small (less than 1 mm long), oval, and yellow to white in color. They are generally easy to see in the seams of clothing, particularly around the waistline and under the armpits. The next life stage of the body louse is called a nymph. It looks like the adult louse but is smaller; about the size of a pinhead. The adult body louse is tan to grayish-white in color, has six legs, and is about the size of a sesame seed (2-4 mm long).
What are the signs and symptoms of body lice infestation?
The most common signs of body lice infestation are intense itching and development of a rash caused by an allergic reaction to the bites. A long term body lice infestation may lead to thickening and discoloration of the skin, particularly around the waist, groin, and upper thighs, causing a condition called "vagabond’s disease". Because intense itching may also occur, scratching can lead to secondary bacterial or fungal infections.
Can body lice transmit disease?
Yes, trench fever, epidemic typhus, and louse-borne relapsing fever can be transmitted by the human body louse. Infections with the organism that causes trench fever are occasionally seen in the United States. Homeless individuals with chronic alcoholism and body lice infestation are at higher risk for infection with the agent of trench fever than the general population. Epidemic typhus and louse-borne relapsing fever are rarely, if ever, reported in the United States.
How are body lice spread?
Body lice are spread among individuals living in unsanitary, crowded conditions when clothing and/or bedding are shared. Infestations are most common in homeless populations in the United States. Lice will not survive off the host without feeding for
more than 1 to 2 days. Eggs can survive, however, on clothing for up to 30 days away from a host.
How are body lice infestations diagnosed?
Infestations are diagnosed by finding eggs and lice in the seams of clothing and occasionally by observing lice crawling or feeding on the skin. Body lice are usually found on clothing that is close to the skin and will be seen on other layers only when there is a heavy infestation.
How are body lice infestations treated?
The infested person should shower; in extreme cases, individuals with extensive body hair may apply an over-the-counter louse medication (pediculicide – same products used for head lice treatments) to the body. Infested clothing and bedding should be washed in hot water (130°F) and then placed in a clothes dryer on the hot cycle.
How can body lice infestations be prevented?
Avoid sharing clothing or bedding. Remove and wash clothing frequently (at least once per week on a high heat setting). Bathe regularly; bathing can also reduce itching and chance of secondary bacterial or fungal infections.
Revised June 2017