lice

lice: They are called cooties or crabs and are so small that it is hard to see them without a magnifying glass. They can live on any part of the body that has hair, where they cement clusters of eggs to the hair shafts. They crawl from place to place, puncturing the skin and sucking blood. They are lice.

Cause Three species of lice affect humans. Prediculosis capitis, or head lice, infest the scalp. Pediculosis corporis, body lice, inhabit clothing and bedding and bite the skin they contact. Pediculosis pubis, pubic lice, are found in the pubic hair around the genitals.
Lice are often called crabs because they look like tiny crabs. They are a bit more than 1/16 inch long, the size of a sesame seed. Their tiny, white, elongated eggs are called nits; the eggs hatch into larvas. All three generations can be found on the body at the same time.
Lice feed on human blood and move from place to place by crawling. They attach to the skin of the human host and bite to suck out the blood.

Incidence Outbreaks of head lice occur frequently among young children in day-care centers, elementary schools, and day camps. These outbreaks can occur at any time, but are seen most often in September. Body lice often are associated with lack of cleanliness; they tend to be found in clothing that is not cleaned regularly. Pubic lice are usually passed during intimate sexual contact.

Symptoms you are likely to notice Intense itching in the area of infestation is usually the first sign that a person has lice. The person may also notice the lice themselves or clusters of nits attached to body hairs. (A handheld magnifying glass is useful for this observation.)

Symptoms your physician may observe The physician may diagnose lice infestation by observing lice or nits, or by observing puncture marks where the lice have fed.

Treatment options Body and pubic lice infestations are usually treated with medicated lotions. Some of the lotions can be purchased without a prescription but others require a prescription. The lotion is put on liberally to cover the affected area and is left on overnight. It is then washed off and clean clothing is put on. Special shampoos are used to get rid of head lice; a special comb, called a nit comb, can help remove the eggs. To be sure that all stages of the louse life cycle are destroyed, the treatment is repeated after seven to ten days. Lice and their eggs sometimes get onto the eyebrows and eyelashes. Petroleum jelly rather than medicated lotion is used to destroy lice in these sensitive areas.
All clothing, towels and bedding the infested person had contact with should be washed in hot water and dried in a dryer or dry-cleaned. All individuals in a household should be treated at the same time to prevent any further spread.
Antibiotics may be prescribed if scratching has caused an infection.

Stages and progress It can take two to three weeks after lice inhabit the body before intense itching begins. This is the length of time it takes the eggs to hatch and grow into adults. Although body lice can carry typhus, a serious disease, the most common complication of untreated lice infestation is secondary infection caused by scratching too hard.
Untreated, the infestation increases and can spread to others through shared clothing, towels, bedding, and sexual contact.

Prevention Head lice in children are very common. It is important to look for lice and nits whenever a child scratches his or her head a lot. If lice are found, notify the public health department or school so that an outbreak can be prevented.
Body lice can be prevented by good housekeeping practices. Thorough, frequent cleaning of clothing and linens reduces the likelihood of body lice infestations. Sharing only clean clothing can reduce the possibility of lice finding new hosts.
Pubic lice are more of an embarrassment than a health hazard. Prompt treatment of all sex partners will prevent the spread to others.

Killing lice saved more lives in World War II than any weapon World War II, in the late 1930s and early 1940s, was the largest conflict between nations in recorded history. Battles raged in all parts of Europe, in Asia, in Africa, and across much of the Pacific Ocean. Over 400,000 Americans died in the war, most of them as a direct result of fighting. But near the end of the war a serious epidemic of typhus was killing American, European, and Asian soldiers faster than any weapons.
At the beginning of World War II the Swiss scientist Paul Müller had discovered that a chemical known as DDT is a powerful killer of insects, including lice. By the end of the war DDT in powder form was being produced. Soldiers were dusted with DDT powder, which stopped the epidemic by killing the lice that transmitted typhus. Later scientists calculated that without DDT far more soldiers and civilians would have died from typhus than had been killed from all the weapons of war.
By the early 1960s, however, the widespread use of DDT was recognized as a possible health problem itself. DDT was banned for most uses in the 1970s in the United States.