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|Complications||Herpes Zoster (Shingles)|
Herpes zoster, also known as shingles, is a disease caused by the varicella-zoster virus (VZV), the same virus that causes chickenpox. It affects an estimated 2 in every 10 people in their lifetime. Shingles are most common in people over age 50 or with weakened immune systems.
The first sign of shingles is often burning or tingling pain, or itch, in one particular location on only one side of the body. After several days or a week, a rash of fluid-filled blisters, similar to chickenpox, appears in one area on one side of the body. Recent studies have shown that subtle cases of shingles with only a few lesions, or none, are more common than previously thought. These cases will usually remain unrecognized. Cases without any known lesions are known as zoster sine herpete.
Shingles pain can be mild or intense. Some people have mostly itching; some feel pain from the gentlest touch or breeze. The most common location for shingles is a band, called a dermatome, spanning one side of the trunk around the waistline. The second most common location is on one side of the face around the eye and on the forehead. However, shingles can involve any part of the body. The number of lesions is variable. Some rashes merge and produce an area that looks like a severe burn. Other patients may have just a few scattered lesions that don't cause severe symptoms.
For most healthy people, shingles rashes heal within a few weeks, the pain and itch that accompany the lesions subside, and the blisters leave no scars. Other people may have complications that linger for months or years.
Virtually all adults in the United States have had chickenpox, even if it was so mild as to pass unnoticed, and thus may develop shingles later in life. In the original exposure to VZV (chickenpox), some of the virus particles leave the blood and settle into clusters of nerve cells (neurons ) called sensory ganglia, where they remain for many years in an inactive (latent) form. The sensory ganglia, which are adjacent to the spinal cord and brain, relay information to the brain about what the body is sensing - heat, cold, touch, pain.
When the VZV reactivates, it spreads down the long nerve fibers (axons) that extend from the sensory cell bodies to the skin. The viruses multiply, the telltale rash erupts, and the person now has herpes-zoster, or shingles. With shingles, the nervous system is more deeply involved than it was during the bout with chickenpox, and the symptoms are often more complex and severe.
Shingles attacks can be made less severe and shorter by using prescription antiviral drugs: acyclovir, valacyclovir, or famcyclovir. Acyclovir is available in a generic form, but the pills must be taken five times a day, whereas valacyclovir and famcyclovir pills are taken three times a day. It is important not to miss any doses and not to stop taking the medication early. Antiviral drugs can reduce by about half the risk of being left with postherpetic neuralgia, which is chronic pain that can last for months or years after the shingles rash clears. Doctors recommend starting antiviral drugs at the first sign of the shingles rash, or even if the telltale symptoms indicate that a rash is about to erupt. Even if a patient is not seen by a doctor at the beginning of the illness, it may still be useful to start antiviral medications if new lesions are still forming. Other treatments to consider are anti-inflammatory corticosteroids such as prednisone. These are routinely used when the eye or other facial nerves are affected.