Body lice

Overview

Body lice are tiny insects, about the size of a sesame seed. Body lice live in your clothing and bedding and travel to your skin several times a day to feed on blood. The most common sites for bites are around the neck, shoulders, armpits, waist and groin — places where clothing seams are most likely to touch skin.

Body lice are most common in crowded and unhygienic living conditions, such as refugee camps and shelters for homeless people. They can also spread from contact with an infected person's clothes. Body lice bites can spread certain types of diseases and can even cause epidemics.

Clothing and bedding that have been infested with body lice should be laundered in hot, soapy water and machine dried using the hot cycle.

Symptoms

Body lice bites can cause intense itching, and you may notice small areas of blood and crust on your skin at the site of the bite marks.

See your doctor if improved hygiene doesn't remove the infestation, or if you develop a skin infection from scratching the bites.

Causes

Body lice are similar to head lice but have different habits. While head lice live in your hair and feed on your scalp, body lice usually live in your clothes and bedding. They travel to your skin several times a day to feed on blood.

Your clothing seams are the most common places for body lice to lay their eggs (nits). You can become infested with body lice if you come into close contact with a person who has body lice, or with clothing or bedding that is infested with body lice.

Risk factors

People who are at higher risk of body lice tend to live in crowded, unclean conditions. They include:

• War refugees
• Homeless people
• People displaced by natural disasters

Dogs, cats and other pets do not spread body lice.

Complications

Body lice infestations usually cause minimal problems. However, a body lice infestation sometimes leads to complications such as:

• Secondary infections. When body lice scratch and dig to feed on your blood, they may irritate your skin. If you scratch to relieve itching, this also can irritate your skin. If your skin becomes raw from these irritations, other infections may develop.
• Skin changes. If you're infested with body lice for a long time, you may experience skin changes such as thickening and discoloration — particularly around your waist, groin or upper thighs.
• Spread of disease. Body lice can carry and spread some bacterial diseases, such as typhus, relapsing fever or trench fever.

Prevention

To prevent body lice infestation, avoid having close physical contact or sharing bedding or clothing with anyone who has an infestation. Regular bathing and changing into clean clothing at least once a week also may help prevent and control the spread of body lice.

Diagnosis

You or your doctor can usually confirm a body lice infestation through a visual examination of your body and clothing items. The presence of eggs and moving lice confirms infestation.

Treatment

Body lice are primarily treated by thoroughly washing yourself and any contaminated items with soap and hot water and drying clothing and bedding in a machine dryer using the hot cycle. Dry cleaning and ironing clothing that cannot be washed also is effective.

If these measures don't work, you can try using an over-the-counter lotion or shampoo that has 1% permethrin (Nix) or pyrethrin. If that still doesn't work, your doctor can provide a prescription lotion. Lice-killing products can be toxic to humans, so follow the directions carefully.

Self care

You can usually get rid of body lice by cleaning yourself and any personal belongings that may be contaminated. Wash infested bedding, clothing and towels with hot, soapy water — at least 130 F (54 C) — and machine dry them on high heat for at least 20 minutes.

Clothing that can't be washed may be dry cleaned and ironed.

Items that can't be washed or dried should be sealed in a plastic bag and stored in a warm area for two weeks. Mattresses, couches and other upholstered furniture items should be hot ironed or sprayed with lice-killing products to eliminate eggs from seams. Exposure to infested items should be avoided for two weeks.

Preparing for your appointment

If you can't get rid of body lice on your own, you may need to talk to your family doctor.

What you can do

Before the appointment, you may want to write the answers to the following questions:

• How long do you think you've had body lice?
• What are your symptoms?
• How were you infested with body lice?
• Have you been in contact with others since noticing the body lice? What treatments have you tried?
• Do you have any chronic health problems?
• What medications and supplements do you take?

What to expect from your doctor

During the physical exam, your doctor will examine your skin and the seams of your clothes.