An Introduction to Body Lice
Also called Pediculus humanus corporis, body lice are small, wingless insects found on clothing and the body of infested people. A body louse (body lice is plural) has three pairs of legs located directly behind the body. The legs end in sharp claws that are designed for feeding and allow the louse to hold on tightly to clothing or hair.
When a person is infested with lice (whether it is body lice,
head lice, or
pubic lice), the condition is known as pediculosis. However, body lice are not the same as head lice.
Lice found on the hair and head are caused by an infestation with another parasite known as
Pediculus humanus capitis.
Anyone can get body lice. Such infestations are common and are found worldwide, affecting people of all races. These infestations spread rapidly under crowded conditions where hygiene is poor and where there is frequent contact among people.
In the United States and other developed countries, body lice are found mainly in homeless, transient populations who don't have regular access to baths or changes of clothes. Infestation is unlikely to persist on anyone who bathes regularly and who has regular access to freshly laundered clothing and bedding.
How Are They Transmitted?
Body lice are contagious. Contact with an infested person's clothing or bedding is the most common way that transmission occurs. They can also be spread through direct skin-to-skin contact with an already infested person.
Unlike
head lice, which do not transmit disease, body lice can, in some cases, spread other diseases. Epidemics of typhus and louse-borne relapsing fever have been caused by body lice.
Though typhus is no longer widespread, epidemics still occur in the following cases:
- During times of war
- During civil unrest
- During natural disasters
- In refugee camps
- In prisons where people live crowded together in unsanitary conditions.
Typhus still exists in places where climate, chronic poverty, and social customs prevent regular changes and laundering of clothing.
The Life Cycle of Body Lice
There are three forms of body lice:
- The egg (also called a nit)
- The nymph
- The adult.
The Nit
Nits are the eggs of body lice. They are quite small (about the size of a knot in thread) and can be hard to see. They are generally easy to see in the seams of clothing, particularly around the waistline and under armpits. They may also be firmly attached to the hair shaft. They are oval in shape and are usually yellow to white in color.
Nymph
The nit hatches into a baby body louse called a nymph. It looks like an adult body louse, but is smaller. To live, the nymph must feed on blood.
Adult Body Louse
The adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white in color. Adult lice can live up to 30 days on a person's body. To live, adult lice need to feed on blood. If the body louse does not get a blood meal, it dies within 10 days.
The most common symptom of body lice is frequent, intense itching. This is because the saliva of the body lice causes an allergic reaction.
Long-term infestations may lead to thickening and discoloration of the skin, particularly around the waist, groin, and upper thighs.
A body lice diagnosis is made by looking closely in the seams of clothing and on the body for eggs and for crawling lice. They are most commonly seen along the seams of clothing. It is not uncommon for clothing to contain several hundred active lice. The body usually has a lot fewer active lice. Typically, when
diagnosing body lice, the body will contain less than ten active lice.
Body lice live primarily on clothing. Therefore, in a lot of cases, an infestation can be treated by giving the person a clean change of clothes and a shower, and by laundering or throwing away all worn clothing, bed linens, and towels. In some cases, medications may be needed in order to treat an infestation.
