Body Lice

What Is It?

Body lice are small, parasitic insects found on the human body or on clothing. These creatures are very similar to head lice, but they typically do not infest the head. Instead, they spend most of their life in an infested person's clothing, crawling onto the skin to feed on the host's blood one or more times a day. Female lice lay their eggs on the seams of clothing near the skin, where body heat allows them to hatch in about a week. A female louse (a single lice) can lay up to 300 eggs in her lifetime at a rate of about nine or 10 per day. Eggs require temperatures between 75 and 100 degrees Fahrenheit to hatch, and take between three and five weeks to develop into adults.

Symptoms

An infestation with body lice usually causes intense itching. Where the lice have been feeding, small welt-like marks often develop, along with redness and swelling. In certain people, infestations can cause hives even on areas of the skin not infested directly. In underdeveloped countries, body lice may transmit trench fever, relapsing fever and epidemic typhus due to poor sanitation and overcrowding.

Diagnosis

Body lice are apparent in the clothing of an infested person. Lice in all stages of development can be found, especially along the seams of clothes worn close to the body. Someone infested with body lice typically will have 10 or fewer active lice on their skin at any one time, since the lice only return to the skin surface to feed. Body-lice infestation is more common in the winter months, when people may wear layers of clothing. This creates a warm, moist environment perfect for lice. Wearing the same garments without washing for prolonged periods of time increases the risk of infestation.

Expected Duration

Body-lice infestations can persist indefinitely without treatment. With treatment, the condition can be eliminated immediately.

Prevention

Body lice are spread by direct person-to-person contact or by contact with infested bedding or clothing. To prevent infestation, avoid sharing clothes and bedding and close contact with an infested person. It is not necessary to quarantine infested people to avoid spreading body lice. It is important to remember that body lice can survive for a day or two on clothing that is off the body, so avoid contact with clothing or other items that recently have been in contact with an infected person.

Treatment