Lice and scabies are two types of skin conditions that are caused by ectoparasites, or parasites that that live on the outside of their hosts. A parasite obtains nourishment and/or protection from another organism, called a host.
Lice (also called pediculosis) are tiny, parasitic insects that feed on blood from their hosts, which may be human. When a human becomes infected with lice, it is not considered a major health concern. However, it typically causes the skin to become red and itchy.
There are several types of lice, including head lice, body lice, and pubic lice. Head lice develop on the scalp, and they may be visible near the ears, shoulder, and at the nape of the neck. The lice produce small eggs, called nits, which attach to the shaft of hairs. After about one week, the nits hatch and more lice are then present. Body lice spend most of their lives on a person's clothing, crawling on the person's skin to feed a couple times a day. The females attach their sticky eggs to the seams and folds of clothing. Pubic lice, commonly called crabs, are found on the skin and hair of the pubic area and eyelashes. Lice are easily spread through close personal contact with an infected person or his/her belongings.
Scabies is a contagious skin disease that is caused by microscopic mites that live three to four weeks in a person's skin. The female mite burrows into the skin's surface to lay her eggs. The mites, eggs, and their waste cause an inflammatory response in the host results in itching, redness, and mild swelling of the skin.
Both lice and scabies can be successfully treated with over-the-counter products and/or prescription-strength anti-parasitic medications. It is also recommended that individuals wash and vacuum items that may be contaminated to prevent re-infections. Also, individuals who live with or have close personal contact with someone who has lice or scabies should receive treatment as well.

Related Terms

Allergic reaction, anti-parasitics, antihistamines, ectoparasites, host, mites, nit comb, nits, parasites, parasitic, parasitic infection, Sarcoptes scabiei, scabicide, skin infection, vinegar rinse.