June 30, 2006

Doctor’s Corner:

Chicken pox

By Eduardo Grunvald, M.D.

Chicken pox is a familiar condition. But a related one that strikes adults, called shingles, can be even more miserable and dangerous than the itchy rash most common in childhood.

About 10 to 15 percent of normal adults can be expected to get shingles during their lifetimes.

Shingles —its scientific name is Herpes Zoster— is actually a reactivation of the chicken pox virus. The two most common groups affected by shingles are the elderly and those whose immune systems have been weakened by disease or medications.

In fact, the risk of developing shingles climbs more steeply after age 65, and certain sources indicate half of all individuals who live to be 85 will have developed the condition.

When reactivation of the virus occurs, it travels down the nerves to the nerve endings in the skin, causing a very irritating and painful rash. One of the possible symptoms is called allodynia, which means that even a light touch or a gentle breeze across the affected skin can be excruciatingly painful. There are anti-viral medications that, if started early enough, can help shorten the duration of the illness but cannot prevent its occurrence.

Fortunately, researchers have recently developed a vaccine for shingles. It’s called Zostavax, different from the chickenpox vaccine given to children.

Vaccine therapy is a hot topic of medical research. This is because it is usually easier to prevent disease than to treat or cure it.

To better appreciate the importance of this medical breakthrough, one must understand the condition and its consequences.

Chicken Pox is caused by a virus called Varicella Zoster. Most people are infected during childhood, causing the well-known illness characterized by a very itchy rash and flu-like symptoms. Chicken pox resolves but the virus continues to live dormant in the spinal cord for the remainder of the person’s life.

Under certain conditions, the virus “reactivates” as shingles.

Unfortunately, in some individuals, after the shingles rash resolves, a very painful condition —Post Herpetic Neuralgia— develops and can last for months, and in some cases years. It can be very debilitating and sometimes requires very potent medications just to make the symptoms tolerable.

The unique aspect of this new vaccine is that it does not prevent infection of the virus —it has been living dormant in the patient’s body for many decades— but reduces the risk of reactivation, thus reducing the risk of developing shingles.

San Diego’s Dr. Michael Oxman of the VA Medical Center and UCSD School of Medicine, in collaboration with colleagues across the country, led the study that developed this important vaccine.

The investigation took place from 1998 to 2001 and involved more than 38,500 patients nationwide, all older than 60. Over three years of follow up showed patients receiving the vaccine had half the probability of developing shingles when compared to patients who did not receive the vaccine.

Moreover, the likelihood of developing Post Herpetic Neuralgia —the most devastating complication of shingles— was reduced by two thirds in patients who received the vaccine.

These are very important results, translating into potential reduction of suffering in hundreds of thousands of people.

Not all medical professionals have the vaccine yet but if you are older than 60, you may want to discuss the benefits of the vaccine with your doctor. Those unfortunate people who have developed shingles and Post Herpetic Neuralgia know how devastating it can be, both in personal suffering and in economic losses from reduced productivity. Now there is hope from a simple shot in the arm.

Dr. Grunvald is Assistant Clinical Professor, Department of Medicine at the Perlman Internal Medicine Group, UCSD Medical Center.

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