Shingles.

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Shingles.
Shingles or Herpes Zoster, disorder in which a rash of small blisters develops on the skin. Shingles is caused by the varicella-zoster virus, the same virus that causes
chicken pox. While the exact cause of shingles is not understood, scientists theorize that during an attack of chicken pox, the virus may invade large clusters of neurons
(nerve cells) found on either side of the spinal cord. The virus may live dormant within these neurons for years, held in check by the body's immune system. But if the
immune system becomes impaired, perhaps during the normal aging process or as a result of disease, the virus can reactivate, causing neurons to become inflamed.
Blisters develop on the skin that lies above the inflamed neurons. In the United States shingles affects two in every ten persons in their lifetime. An estimated 1 million
people develop shingles each year, and many scientists believe the number is likely to rise as the population ages.
In a typical attack of shingles, a person first feels pain in the area that will later break out in blisters. Other initial symptoms include fever, headache, muscle soreness,
fatigue, stomach upset, and diarrhea. After three to five days of these initial symptoms, the blisters appear, often accompanied by burning and tingling. The blisters are
usually confined to one side of the body, most commonly in an area extending from the upper half of the spine to the breastbone. The face, abdomen, arms, and legs
may also be affected. The rash usually goes away after a few weeks without complications. About 50 percent of shingle-sufferers over age 60 have persistent skin
irritation and pain in the affected area for as long as six months. A single attack of shingles usually confers lifelong immunity against further outbreaks.
Treatment of shingles may include the use of calamine lotion to relieve itching. A lidocaine patch, a stretchy bandage coated with a long-acting topical anesthetic, may
be applied to the painful area to numb affected nerve endings and temporarily relieve pain. In addition, a physician may prescribe antidepressants and other drugs that
help calm inflamed nerves, lessening pain. When shingles is diagnosed in patients with suppressed immune systems, such as those with acquired immunodeficiency
syndrome (AIDS) or cancer, the antiviral drug acyclovir may be prescribed.
In 1995 the United States Food and Drug Administration (FDA) approved a vaccine for chicken pox. The vaccine has reduced the number of chicken pox cases in some
regions of the United States by 90 percent. In 2005 medical researchers reported that a more potent version of the vaccine was successful in preventing shingles
among Americans aged 60 and older. A three-year-long study involving nearly 39,000 people in that age group found that the vaccine was more than 50 percent
effective in reducing the incidence of shingles. It was more than 60 percent effective in preventing postherpetic neuralgia, an extremely painful condition that often
occurs as a complication of shingles. Postherpetic neuralgia can last for years and can seriously harm a person's quality of life. It is not effectively treated with current
medication. In the study half of the participants received the experimental vaccine and half received a placebo. Following the successful results of the study, an advisory
panel to the FDA approved the vaccine, which is made by the drug manufacturer Merck & Co., Inc. In 2006 the FDA formally approved the vaccine.

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