A Painful Rash - Is It Shingles?
Shingles (Herpes zoster) is an extremely painful skin rash caused by the Varicella zoster virus, the same virus that causes chickenpox. In people who have had chickenpox, the virus is never fully cleared from the body; instead, it remains dormant in the nerve tissues. When physical or emotional stresses to the body weaken the immune system, the virus reactivates and spreads along the nerve fibers to the particular area of skin supplied by the involved nerve (called a dermatome). The virus responsible for chickenpox and shingles is a member of the Herpesviruses, although it is not the same as the Herpes simplex 1 and 2 viruses that cause cold sores and genital herpes, respectively.
Pain, itching, tingling, or burning of the skin often precede the rash in an outbreak of shingles. The blisters that develop resemble the lesions of chickenpox but are concentrated in the area supplied by the involved nerve. Rarely, more than one nerve is involved. Blisters may occur along the entire path of the nerve or only in certain areas supplied by the nerve. As with the blisters of chickenpox, the blisters in shingles eventually burst and begin to crust over and heal. The entire outbreak can last for three to four weeks.
Before the blisters are crusted over, the virus can be spread to anyone who does not have immunity to chickenpox through vaccination or previous infection.
The pain of shingles can be so severe, even before the rash develops, that it mimics dangerous conditions such as appendicitis, kidney stones, or a heart attack, depending upon the location of the nerve that is affected. The appearance of the characteristic rash is usually sufficient to establish the diagnosis of shingles. Antiviral drugs are sometimes prescribed to reduce the duration of the rash, but their effectiveness is limited. Steroids or pain medications are sometimes given to help control the pain of shingles.
Most people with intact immune systems recover completely from shingles, although recurrences are possible. Since immune function declines with age, older people are most vulnerable to shingles. About half of shingles cases occur in people over age 60. People with weakened immune systems due to cancers, chemotherapy, or HIV infection are also at increased risk for the development of shingles. In 2006, the U.S. Food and Drug Administration (FDA) approved the first vaccine against shingles. The vaccine, Zostavax, which is recommended for use in people over 60, has been shown to be 60% effective in the reduction of symptoms of shingles and reduces the incidence of the painful complication of shingles known as postherpetic neuralgia by at least two-thirds.
Last Editorial Review: 1/14/2008