Body lice

Body lice (Pediculus humanus corporis) are small blood-sucking insects that live on the body of infested humans and in their clothing or bedding, particularly the seams. Body lice can spread from person to person and are normally associated with crowded and unhygienic living conditions.

Body lice should not be confused with head lice (that infest the scalp) or pubic lice (that infest the pubic hair). They are another species of louse. In Australia body lice are less common than head lice or pubic lice – they do not cause disease but can result in secondary bacterial infection of the skin caused by scratching.

What is it
Body lice are flat wingless insects with six legs ending in a claw. They are greyish or brown in colour and range in size from 2–5mm. Body louse eggs (nits) are small, white and oval-shaped. Lice lay their eggs in the seams of any clothing worn next to the skin, such as underwear. A special gluey secretion anchors each egg to clothing fibres, or sometimes to body hairs.

The eggs take five to 14 days to hatch, depending on the availability of the host’s body heat. If the infested item of clothing is removed at night and the eggs are deprived of continuous warmth, it will take longer for the eggs to hatch. Seven days after hatching the egg matures into an adult louse. The female body louse lives for around four weeks and lays approximately eight eggs per day. Without a constant source of blood a louse will die within two to five days.

Mature lice survive by feeding on human blood and live exclusively inside clothing. Their strong grasping claws allow them to move through clothing and against the skin. They feed often and at any time of day or night and typically choose a site where the skin is soft, creased and close to clothing such as the armpit or waistline. The insect bites into the skin and sucks blood. Its grey body takes on a darkened colour as blood is ingested.

Symptoms and signs of body lice
The bite of a body louse has certain characteristics, including:

• Initially, a tiny red dot appears
• The red dot rises into a small cyst-like lump or papule
• The area becomes inflamed
• The bite causes irritation and severe itching
• Secondary infection may result from the continuous scratching
• Body lice are visible to the naked eye and occasionally a body louse can be seen crawling or feeding on the skin, or crawling lice may be noticed in the seams of clothing or bedding.

• Appropriate insecticide treatment may be prescribed and is readily available from pharmacies
• Other medication to reduce itching and control secondary infection may also be required
• Increased level of personal hygiene with regular bathing or showering is essential for control
• Avoid close contact with infested persons, their clothing and bedding
• Regular changing and laundering of clothes (especially underwear), or disposal of affected clothing is required
• Check seams of any second-hand clothing or bedding for the presence of body lice
• Clothing and blankets recently used by an infested person should be laundered in hot water (greater than 60ºC) and preferably tumble dried or ironed with all seams turned outwards
• Items of clothing that cannot be laundered or dry-cleaned can be ironed paying special attention to seams, or may be sealed in a plastic bag for four days
• Thoroughly vacuum mattresses paying attention to seam, creases and under buttons.

• Your doctor

• Body lice are small blood-sucking insects that live inside clothing, particularly the seams.
• People who live in unhygienic and crowded conditions, where personal hygiene is neglected and clothes are not changed, are most susceptible to body lice infestations.
• An increased level of personal hygiene with regular bathing or showering is essential for control.

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