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Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Body lice

What are body lice?

Lice are insects that infest humans, causing a condition called pediculosis. The proper name for the body louse is Pediculus humanus corporis.

How do you get body lice?

Infestation with body lice is uncommon in comparison to head lice. Body lice tend to infest people in extreme states of poverty or personal neglect, particularly when unwashed and wearing the same clothing for weeks-on-end.

The risk of catching body lice is increased in close, crowded living situations, such as in refugee camps and crowded buses/trains. Shared bedding and/or clothing or very close contact with a person infested with lice can be the cause of body lice spreading.

Body lice in the past have been responsible for spreading diseases such as typhus.

What do body lice look like and where do they live?

The body louse is larger than the head louse and is between 2 and 4mm in size. The body louse is flat and white to grey in colour. Body lice do not live on the body, they only crawl onto the body when they need to feed. They can survive for up to 10 days away from the human body without a blood meal. When they are not feeding they live and lay their eggs on the fibres of clothing, mainly close to the seams.

A female body louse can lay 10-15 eggs per day on clothing and on average, 20 adult female lice are usually found on a person with an infestation.

How do you get rid of body lice?

Treating the body infested with lice is not usually necessary as the lice live on the clothing. If the infestation is widespread and covers much of the body, insecticides used in the treatment of head lice may also used in the treatment of body lice.

Environmental measures are the focus of treating body louse infestations. Laundering of clothing and bed linens using hot washes is essential to killing body lice and their eggs on clothing.

Regular hot washing of clothes and bathing has led to a decrease in incidence of body lice but during wartime and in some undeveloped countries the condition can still occur. Household contacts and close friends should also be educated about hygiene and how to launder clothing and linen to prevent the spread of body lice and reinfestation.

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Author: Steven Lamb MBChB, Department of Dermatology, Health Waikato. Updated by Vanessa Ngan, Staff writer, 1 February 2014.

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