Shingles (Herpes Zoster)

Shingles is another name for herpes zoster, an acute infection caused by reactivation of the varicella zoster virus (VZV). It is characterized by a painful skin rash with blister-like lesions which is usually localized to one side of the body, often the face or trunk. Shingles may also produce fever, headache, chills, swollen lymph nodes, joint or abdominal pain and impaired vision and hearing; very rarely serious complications may occur including pneumonia, blindness, hearing problems, paralysis, encephalitis and death. Shingles usually clears up without treatment in two to three weeks and usually does not recur. Medical treatments available include antivirals such as Acyclovir, corticosteroids such as prednisone to reduce inflammation, and pain and anti-itching medications for symptom relief.

Shingles is caused by the same virus which causes chicken pox; because VZV remains in the nerve cells of the body after the chicken pox episode is over, anyone who has had chicken pox in the past may develop shingles. It is not known why the virus is reactivated in some people, it is more common in people who are immunosuppressed due to medical conditions such as AIDS or who are receiving immunosuppressive drugs, and in people age 50 and older. Consequences may also be more serious in older person: for instance half of shingles patients over age 60 have lingering neuralgia (nerve pain). There are about 300,000 to 600,000 cases of shingles annually in the United States, and about 12 percent of the cases have sequelae, the most common of which is postherpetic neuralgia. Incidence in the United States is 2.2 cases per 1000 per-son-years, with persons over age 75 age highest risk with 14.2 cases per 1000 person-years.

Shingles occurs worldwide because its root cause, infection with VZV, also occurs worldwide. Shingles rates in developed countries may fall in the future: the introduction of varicella vaccines which offer protection against chicken pox are commonly administered in childhood in most industrialized countries, so that the rate of childhood chicken pox is much lower than previously. However, the effectiveness of this vaccine in preventing shingles is not known, because widespread use has occurred too recently to allow studies of older adults vaccinated as children. Studies with immunocompromised individuals indicate that childhood varicella vaccination seems to lessen the risk of shingles, but further studies are needed to determine if this also holds true for the general public.

A shingles vaccine, Zostavax, was licensed in 2006 by the Food and Drug Association for shingles prevention in persons age 60 and older; it does not treat the disease once it has developed. In clinical trials, it prevented shingles in about half of test subjects and prevented post-herpetic neuralgia in two-thirds of the subjects, and was most effective for people 60–69 years of age, although it also conferred some protection on older individuals. The Advisory Committee on Immunization Practices recommends vaccination with a single dose of Zostavax for Americans aged 60 and over, with the exception of persons with active tuberculosis, a compromised immune system, or who are allergic to gelatin or the antibiotic neomycin.

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