Lice

Facts, Identification & Control

Latin Name

Family Pediculidae

Appearance


What Do Lice Look Like?
Adults are 2 to 4.2 mm long, wingless and flattened. They are whitish to grey in color and have a hooklike claw at the end of their legs.

Behavior, Diet & Habits

Lice are parasites that prey on mammalian and avian orders. There are several species of lice, with only certain species relying on human hosts.

Bird Lice
Lice that feed on the human body may also be found in the folds and seams of clothing. Because birds can have lice, bird handlers can also be bitten by the lice that bite birds.

Head Lice
Head lice are the most common of human infestations and do not indicate a lack of cleanliness. Lice can be present in short or long hair, though they do require some hair. Human head lice are often found behind the ears or near the hairline, at the base of the neck. Their eggs, known as nits, thus the term “nit-picking,” are attached to a host’s hair with specialized saliva. Nits are white in color and are located near the scalp on individual strands of hair.

Body Lice
Body lice resemble head lice, though they make their homes in clothing rather than on the scalp. They are not as common, since people usually do not wear the same clothing continuously for days at a time or without washing it. Body lice infestations are characterized by severe itchiness and red marks on the body. These bites can result in skin infection. 

Can Body lice spread disease?
Body lice (Pediculus humanus) can spread epidemic typhus (Rickettsia prowazekii), trench fever (Bartonella quintana) and louse-borne relapsing fever (Borrelia recurrentis). 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 may occur in places where climate, chronic poverty, social customs or war and social upheaval prevent regular changes and laundering of clothing.

Body lice are spread through direct 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. However, in the United States, actual infestation with body lice tends to occur only in homeless, transient persons who do not have access to regular bathing and changes of clean clothes.

Reproduction

Reproduction and development vary depending on lice species. Head lice females produce 50 to 100 round eggs which they secure to a person’s scalp. Body lice lay up to 200 eggs which they usually deposit in a person’s clothing.

Signs of a Lice Infestation

Signs of lice may include skin irritations or sightings of small whitish bugs in the clothing or hair. Nits are an important indicator of head lice.

Intense itching and rash caused by an allergic reaction to louse bites are common symptoms of body lice infestation. As with other lice infestations, intense itching leads to scratching and can cause sores and secondary bacterial infection of the skin. When body lice infestation is long lasting, heavily bitten areas of the skin can become thickened and darkened, particularly in the mid-section of the body, producing a condition called “vagabond’s disease.”

More Information

Treating for Lice

Head lice can be removed at home with the use of a nit comb. Body lice can be addressed by thorough body washing. All clothing and bed linens should be washed in hot cycles. Over-the-counter antilice agents are also available, though medical care should be sought if skin or scalp infections develop.

Human Head Lice

Bird Lice