Body Lice Body Lice
Centers for Disease Control and Prevention
What are body lice?
Body lice are parasitic insects that live on clothing and bedding used by infested persons. Body lice frequently lay their eggs on or near the seams of clothing. Body lice must feed on blood and usually only move to the skin to feed. Body lice exist worldwide and infest people of all races. Body lice infestations can spread rapidly under crowded living conditions where hygiene is poor (homeless, refugees, victims of war or natural disasters). In the United States, body lice infestations are found only in homeless transient populations who do not have access to bathing and regular changes of clean clothes. Infestation is unlikely to persist on anyone who bathes regularly and who has at least weekly access to freshly laundered clothing and bedding.
What do body lice look like?
Body lice have three forms: the egg (also called a nit), the nymph, and the adult.
Nit: Nits are lice eggs. They are generally easy to see in the seams of an infested person’s clothing, particularly around the waistline and under armpits. Body lice nits occasionally also may be attached to body hair. They are oval and usually yellow to white in color. Body lice nits may take 1-2 weeks to hatch.
Nymph: A nymph is an immature louse that hatches from the nit (egg). A nymph looks like an adult body louse, but is smaller. Nymphs mature into adults about 9-12 days after hatching. To live, the nymph must feed on blood.
Adult: The adult body louse is about the size of a sesame seed, has 6 legs, and is tan to greyish-white. Females lay eggs. To live, lice must feed on blood. If a louse falls off of a person, it dies within about 5-7 days at room temperature.
Where are body lice found?
Body lice generally are found on clothing and bedding used by infested people. Sometimes body lice are be seen on the body when they feed. Body lice eggs usually are seen in the seams of clothing or on bedding. Occasionally eggs are attached to body hair.
Lice found on the head and scalp are not body lice; they are head lice.
What are the signs and symptoms of body lice?
Intense itching (“pruritus”) and rash caused by an allergic reaction to the louse bites are common symptoms of body lice infestation. When body lice infestation has been present for a long time, heavily bitten areas of the skin can become thickened and discolored, particularly around the midsection of the body (waist, groin, upper thighs); this condition is called “vagabond’s disease.”
As with other lice infestations, intense itching can lead to scratching which can cause sores on the body; these sores sometimes can become infected with bacteria or fungi.
Can body lice transmit disease?
Yes. Body lice can spread epidemic typhus, trench fever, and louse-borne relapsing fever. Although louse-borne (epidemic) typhus is no longer widespread, outbreaks of this disease still occur during times of war, civil unrest, natural or man-made disasters, and in prisons where people live together in unsanitary conditions. Louse-borne typhus still exists in places where climate, chronic poverty, and social customs or war and social upheaval prevent regular changes and laundering of clothing.
How are body lice spread?
Body lice are spread through direct physical contact with a person who has body lice or through contact with articles such as clothing, beds, bed linens, or towels that have been in contact with an infested person. In the United States, actual infestation with body lice tends to occur only in persons who do not have access to regular (at least weekly) bathing and changes of clean clothes, such as homeless, transient persons.
How are body lice infestations diagnosed?
Body lice infestation is diagnosed by finding eggs and crawling lice in the seams of clothing. Sometimes a body louse can be seen on the skin crawling or feeding. Although body lice and nits can be large enough to be seen with the naked eye, sometimes a magnifying lens may be necessary to find lice or nits Diagnosis should be made by a health care provider if you are unsure about an infestation.