THE MISERY OF SHINGLES ITS PAIN KNOWS NO CEILING, BUT THIS CONDITION OF THE CHICKEN POX VIRUS MAY YET BE CONTAINED.

Byline: Mariko Thompson Staff Writer

Imagine not being able to wear a shirt because fabric touching your skin causes pain. Or never playing tennis because the rush of air against your forehead as you run toward the ball is unbearable.

For some, chronic skin pain is the devastating aftermath of shingles, a rash triggered by reactivated chicken pox virus lying dormant in the body. Shingles affects an estimated 1 million Americans annually, with this year's tally including late-night talk show host David Letterman. Letterman, who has been sidelined with shingles since late February, is scheduled to return to his show tonight.

Most people completely recover from shingles in three to five weeks. But with age, the likelihood increases that a person will suffer from chronic pain for months or even years afterward - a condition called post-herpetic neuralgia. About 45 percent of patients over the age of 60 will develop post-herpetic neuralgia, compared to about 20 percent overall.

``The pain makes it difficult to function,'' said Dr. Steven Richeimer, director of the USC Pain Center. ``Sometimes it's the air, or clothes, or bedsheets. If you have a hard time imagining this, think of the last time you had a sunburn and imagine stroking your skin with a hairbrush.''

Stupid virus tricks

About one in seven people who have had chicken pox will suffer from an outbreak of shingles later in life. Once chicken pox has run its course, the varicella zoster virus migrates from the skin and lies dormant in nerve tissue along the spinal cord. Doctors aren't sure what reactivates the virus, though the elderly and people with weakened immune systems are at greatest risk.

Shingles is not contagious. However, a person who has never had chicken pox may get chicken pox if exposed to someone who has shingles.

Before the shingles rash appears, the area of skin may burn, tingle or itch. Other symptoms include nausea, fever, chills and headache. The painful lesions typically form a band on one side of the body or face. The rash then blisters and dries out.

When shingles breaks out on the face, the virus also can affect the eyes. Letterman complained of eye pain on his show before he was diagnosed.

Shingles is commonly treated with anti-viral medications such as acyclovir. Anti-seizure and anti-depressant medications can be prescribed to soothe irritated nerves. Richeimer says nerve block procedures - epidurals combining a steroid and a local anesthetic - also can be effective.

Treating shingles aggressively may be the key to avoiding post-herpetic neuralgia. Since pain precedes the lesions, researchers suspect that nerve damage has started before shingles can be diagnosed. The need for preventive treatment is critical because the arsenal of drugs available to counter post-herpetic neuralgia is small and not as potent as doctors would like. Doctors can prescribe anti-seizure medications. Some patients have found relief with the Lidoderm dermal patch.

``The problem with post-herpetic neuralgia is we don't understand why and how it happens,'' said Dr. Michael N. Oxman, professor of medicine and pathology at the University of California, San Diego, who serves on the VZV Research Foundation scientific advisory board. ``It doesn't respond well to conventional pain treatments.''

Dr. Donald Gilden, professor and chairman of the neurology department at the University of Colorado School of Medicine in Denver, has a theory about post-herpetic neuralgia. Instead of returning to dormancy after the shingles attack, the virus remains active at a low level.

Gilden is investigating the anti-viral medication acyclovir, taken intravenously rather than orally. Though Gilden believes the intravenous treatment is more effective at heading off post-herpetic neuralgia, it requires either a week in the hospital or home visits from a nurse - an expensive proposition many insurance plans are reluctant to cover.

``Ultimately, we need a good anti-viral drug to drive the virus back into a latent state,'' Gilden said.

Nailing it down

Oxman of UC San Diego would like to find a way to keep the chicken pox virus dormant forever. He's the lead investigator of a national study for a shingles vaccine. Half of the 38,000 adults enrolled in the study will receive the vaccine, which essentially is a higher dose of the chicken pox vaccine administered to children.

Research suggests having shingles once boosts immunity and keeps most people from having the condition a second time. Parents caring for young children with chicken pox also seem to benefit from a boost in immunity, Oxman said.

``This big (shingles vaccine) study is designed to see if we can imitate Mother Nature,'' Oxman said. ``As our population ages, shingles and post-herpetic neuralgia become a bigger problem.''

Since 1995, the chicken pox vaccine has become routine for children. Does that mean the current generation of children will never have to worry about shingles? Experts say the vaccine reduces but does not completely eliminate the chances of developing shingles. Because the vaccine contains a live virus, the vaccine virus remains dormant in the body just as the natural virus does. So far, children vaccinated for chicken pox appear to be five to 10 times less likely to have shingles, Oxman said.

The full effect of the chicken pox vaccine won't be known for another 50 to 60 years, when the current generation of children reach an age when they are more susceptible to shingles, he said.

The chicken pox vaccine may be good news for kids, but it could be bad news for their parents. Now that their kids don't get chicken pox, parents may lose the boost in immunity that keeps shingles at bay, Oxman said.

``Maybe we'll have shingles a little sooner than we would have otherwise,'' he said.

Facts on shingles

What is shingles?

Shingles is a painful rash that forms a band on one part of the body or clusters on the face. The condition is caused by the reactivation of the chicken pox virus. After a person has chicken pox, the virus remains dormant in the body's sensory nerves near the spinal cord.

Who gets shingles?

Only people who have had chicken pox can get shingles. The risk of shingles increases with age and is more common in people over the age of 50. One in seven people who live to the age of 85 will suffer from shingles at some point in their lives.

What are the symptoms of shingles?

The skin will burn, tingle or itch in the area where the rash will later form. Early signs include mild flulike symptoms such as headache, nausea, fever and chills. The lesions begin as small red bumps. See your doctor as soon as the rash appears. Anti-viral treatments are most effective within 24 to 72 hours of the outbreak.

Is shingles contagious?

No, shingles isn't contagious. However, a person who has never had chicken pox may get it if exposed to shingles.

What is post-herpetic neuralgia?

Chronic pain in the area of the shingles rash that may last months to years. The odds of suffering from post-herpetic neuralgia increase with age.

For more information:

Visit the USC Pain Center Web site at www.helpforpain.com or call [phone].

Visit the VZV (Varicella Zoster Virus) Research Foundation Web site at www.vzvfoundation.org.

Visit the National Institute of Neurological Disorders and Stroke Web site at www.ninds.nih.gov/health-and-medical/disorders/shingles-doc.htm.

CAPTION(S):

3 photos, box

Photo:

(1 -- cover -- color) SHINGLES

Scientists are at work on a vaccine for the viral disease that has sidelined David Letterman

(2) Talk-show host David Letterman's case of shingles first presented itself as eye irritation.

(3) Shingles causes blister-like sores to form on the body. Some recover from the condition within weeks, while others experience pain for months or years.

Box:

Facts on shingles (see text)