By Evelyn Zamula
In Italy, shingles also is called St. Anthony's fire, a fitting name for a
disease that has bedeviled saints and sinners throughout the ages. Caused by
the same varicella-zoster virus that causes chickenpox, shingles (also called
herpes zoster) most commonly occurs in older people. Treatment was once limited
to wet compresses and aspirin. Today's treatments provide a variety of ways
to shorten the duration of a shingles outbreak and to control the associated
pain. Sometimes, however, shingles leads to a chronic painful condition called
post-herpetic neuralgia (PHN) that can be difficult to treat.
After an attack of chickenpox, the varicella-zoster virus retreats to nerve
cells in the body, where it may lie dormant for decades. But under certain conditions,
usually related to aging or disease, the virus can reactivate and begin to reproduce.
Once activated, the virus travels along the path of a nerve to the skin's surface,
where it causes shingles.
Shingles' symptoms may be vague and nonspecific at first. People with shingles
may experience numbness, tingling, itching, or pain before the classic rash
appears. In the pre-eruption stage, diagnosis may be difficult, and the pain
can be so severe that it may be mistaken for pleurisy, kidney stones, gallstones,
appendicitis, or even a heart attack, depending on the location of the affected
nerve.
Pain may come first, but when the migrating virus finally reaches the skin--usually
the second to the fifth day after the first symptoms--the rash tells all. The
virus infects the skin cells and creates a painful, red rash that resembles
chickenpox.
Doctors can distinguish shingles from chickenpox (or dermatitis or poison
ivy) by the way the spots are distributed. Since shingles occurs in an area
of the skin that is supplied by sensory fibers of a single nerve--called a dermatome--the
rash usually appears in a well-defined band on one side of the body, typically
the torso; or on one side of the face, around the nose and eyes. (Shingles'
peculiar name derives from the Latin cingulum, which means girdle or belt.)
If a diagnosis is in doubt, lab tests can confirm the presence of the virus.
The rash usually begins as clusters of small bumps that soon develop into
fluid-filled blisters (vesicles). In turn, the blisters fill with pus (pustules),
break open, and form crusty scabs. In about four or five weeks, the disease
runs its course, the scabs drop off, the skin heals, and the pain fades. Most
healthy individuals make an uneventful, if not particularly pleasant, recovery.
Not everyone sails through without incident, however. Although it's difficult
to resist scratching the itchy rash, it's better to keep hands off, as the damaged
skin may develop a bacterial infection requiring antibiotic treatment. After
such an infection, the skin may be left with significant scarring, some of it
serious enough to require plastic surgery.
Another complication called the Ramsay Hunt syndrome occurs when the varicella-zoster
virus spreads to the facial nerve, causing intense ear pain. The rash can appear
on the outer ear, inside the ear canal, on the soft palate (part of the roof
of the mouth), around the mouth and on the face, neck and scalp. The hearing
loss, vertigo and facial paralysis that may result are usually, but not always,
temporary.
Occasionally, the rash will appear as a single spot or cluster of spots on
the tip of the nose, called Hutchinson's sign. This is not good news. It means
that the ophthalmic nerve is probably involved and the eye may become affected,
possibly causing temporary or permanent blindness.
"My husband was undergoing chemotherapy treatment for prostate cancer," says
Julia Hershfield, of Kensington, Md., "when he developed shingles in his right
eye. The pain was so bad, that he lost all will to live. Shingles finished him."
In people whose immune systems are extremely weakened, the shingles virus can
also spread to the internal organs and affect the lungs, central nervous system
and the brain, sometimes causing death.
Like other members of the herpes family (such as the herpes simplex viruses
that cause cold sores and genital herpes), the varicella-zoster virus that causes
chickenpox never completely leaves the body. Most people don't get chickenpox
a second time. However, anyone who has had chickenpox has the potential to develop
shingles, because after recovery from chickenpox, the virus settles in the nerve
roots.
Researchers are not sure exactly what triggers the virus to spontaneously start
reproducing in nerve cells later in life and reappear as shingles. However,
they do know the virus may reactivate when the immune system is weak.
Certain factors can cause the immune system to let down its guard. Age is one
of them. Immunity declines with aging, so susceptibility to disease increases.
The incidence of shingles and of resulting PHN rises with increasing age. More
than 50 percent of cases occur in people over 60. Older people may also lack
exposure to children with chickenpox, thereby losing an opportunity to boost
immunity and prevent virus reactivation. Although most people have only one
attack of shingles, about 4 percent will have further attacks.
People who have had chickenpox cannot "catch" shingles from someone who has
it. However, people who've never had chickenpox can be infected with chickenpox
if exposed to someone with an active case of shingles. The rash sheds the varicella-zoster
virus and can be contagious. A caregiver or other person who lacks immunity
developed from a prior case of chickenpox or the vaccine must avoid coming into
contact with the rash or contaminated materials.
Also at risk for shingles are people with leukemia, lymphoma, or Hodgkin's
disease, and those whose immune systems have been weakened because they are
HIV-positive, or have undergone chemotherapy, radiation, transplant surgery
with immunosuppression, or treatment with corticosteroids. Moreover, about 5
percent of people with shingles are found to have an underlying cancer, about
twice the number of people in the population expected to have undiagnosed cancer.
It pays to be vigilant when unexplained symptoms occur. "New development of
a rash or pain, especially when it occurs on only one side of the chest or face,
should prompt a visit to the health-care provider," says Therese A. Cvetkovich,
M.D., a medical officer in the Food and Drug Administration's Center for Drug
Evaluation and Research (CDER).
Although viral diseases can't be cured, doctors can prescribe oral antiviral
medications, such as Zovirax (acyclovir), Famvir (famciclovir) and Valtrex (valacyclovir),
that help control the infection by hindering reproduction of the virus in the
nerve cells. "Antiviral therapy may shorten the course of an episode of shingles,"
says Cvetkovich. "However, therapy must be started as early as possible after
symptoms develop--within 48 hours--in order to have an effect."
To relieve pain, the doctor may recommend over-the-counter analgesics (pain-relieving
drugs), such as ibuprofen and naproxen, or prescription drugs, such as indomethacin,
all members of a class of medications known as nonsteroidal anti-inflammatory
drugs. Acetaminophen is also commonly used to relieve the pain. If pain is severe,
doctors may add stronger analgesics, such as codeine or oxycodone.
In some patients, the misery continues long after the rash has healed. Many
of the 1 million people who develop shingles each year experience a complication
called post-herpetic neuralgia (PHN). This term refers to pain that is present
in the affected area for months, or even years, afterward. Although the acute
pain of shingles and the chronic pain of PHN (called neuropathic pain) both
originate in the nerve cells, their duration and the reaction to treatment is
different.
Pain that occurs with the initial outbreak responds to treatment and is limited
in duration. In contrast, PHN lasts longer, is difficult to treat and can be
incapacitating. Furthermore, for unknown reasons, older people suffer more from
this debilitating pain than younger people. In many individuals, the skin is
so sensitive that clothing or even a passing breeze cannot be tolerated on the
affected area. Described by PHN sufferers as agonizing, excruciating, and burning,
the pain can result in an inability to perform daily tasks of living, and lead
to loss of independence and, ultimately, depression and isolation.
"I would rather have ten babies than the pain I've endured for the past ten
years," says 87-year-old Etta Watson Zukerman of Bethesda, Md., who has lost
partial use of her right arm and hand due to nerve damage from PHN. "Nothing
my doctor prescribed helped. I even went to a sports medicine specialist who
recommended exercises. They didn't help either." Many PHN sufferers receive
no relief at all, no matter what medications or therapies they use. And what
works for one doesn't necessarily work for another.
Doctors use other methods to alleviate pain with varying degrees of success.
"One of the relatively new medications that I'm enthusiastic about is the Lidoderm
patch," says Veronica Mitchell, M.D., director of the pain management center
and inpatient pain service at Georgetown University Hospital, Washington, D.C.
"It's the transdermal form of lidocaine and it's been studied in the PHN population
with very good results," adds Mitchell. "We prescribed the Lidoderm patch for
a patient who had intolerable side effects with oral medications--and no relief--and
she's had about a 50 percent-plus improvement in pain relief. It's one of my
first-line therapies." The medication contained in this soft, pliable patch
penetrates the skin, reaching the damaged nerves just under the skin without
being absorbed significantly into the bloodstream. This means that the patch
can be used for long periods of time without serious side effects.
Yet another method used to treat PHN is transcutaneous electrical nerve stimulation,
or TENS. A device that generates low-level pulses of electrical current is applied
to the skin's surface, causing tingling sensations and offering some people
pain relief. One theory as to how TENS works is that the electrical current
stimulates production of endorphins, the body's natural painkillers.
TENS is not for everyone. "TENS didn't help at all," says Einar Raysor of Rockville,
Md. "I found there was a problem in fine-tuning the administration of the electrical
current. Low doses of the electrical current didn't do anything for me. When
the technician increased the current, it gave me a painful response. After this
happened a couple of times, we dropped the treatment."
As a last resort, invasive procedures called nerve blocks may be used to provide
temporary relief. These procedures usually entail the injection of a local anesthetic
into the area of the affected nerves. "We have controversial results in the
terms of the efficacy of nerve blocks," says Mitchell. "I do consider nerve
blocks in treating PHN and I would perform them because there's some evidence
that they work, but the real efficacy is to catch and treat the patient in the
acute shingles phase. As PHN presents mostly in the elderly, and the older patient
often is unable to tolerate some of the medications we use, I find nerve blocks
useful in these cases."
Injection directly into the spine is another option for relief of pain that
is not easily treated. A Japanese clinical study published in the New England
Journal of Medicine found that an injection of the steroid methylprednisone
combined with the anesthetic lidocaine reduced pain by more than 70 percent
in one patient group compared with groups that received lidocaine alone or an
inactive substance.
Before the FDA approved the chickenpox vaccine in 1995, about 95 percent of
the U.S. population developed chickenpox before age 18. Since then, more than
60 percent of American youngsters have been vaccinated against chickenpox.
"The vaccine is a live attenuated strain of the chickenpox virus," says Philip
R. Krause, M.D., lead research investigator in the FDA's Center for Biologics
Evaluation and Research. "However, it's a weaker form so it gives rise to a
milder infection. But in the course of giving rise to this milder infection,
it induces enough immunity to prevent people from getting the natural infection."
It is estimated that the vaccine is between 75 and 85 percent effective in preventing
chickenpox. "But the important thing," says Krause, "is that it is almost completely
effective in preventing severe cases of chickenpox."
Now that we have a chickenpox vaccine, are shingles and PHN on their way out?
Although the FDA hasn't evaluated the effects of the vaccine on shingles, Krause
believes that "in the long term, if you can prevent enough people from getting
the wild (natural) type of chickenpox, you're likely to see a beneficial effect
on the incidence of shingles and post-herpetic neuralgia. But it may take several
generations for this to happen."
Evelyn Zamula is a freelance writer in Potomac, Md.
Since shingles can be very serious in older people, the Department of Veterans
Affairs, the National Institute of Allergy and Infectious Diseases, and Merck
& Co. Inc. are conducting a five-year clinical study at 22 sites nationwide
to determine whether vaccination can prevent shingles in people ages 60 years
and older who have had chickenpox.
As with the chickenpox vaccine now in use, the experimental vaccine is made
from a weakened form of the chickenpox virus, but is much more potent than the
existing vaccine.
"Immunity to the virus declines with advancing age, making older adults vulnerable
to shingles," says Norberto Soto, M.D., principal investigator for the Shingles
Prevention Study at the National Institutes of Health site in Bethesda, Md.
"We believe that by boosting the body's immune response with this vaccine, shingles
and its complications may be prevented."
The clinical trial hopes to recruit 37,200 volunteers. Besides the age requirement,
the enrollees must be in good health and never experienced shingles.
The study, which began in 1999, is a "double-blind" study, which means that
neither the researchers nor the participants know who is receiving the experimental
vaccine or an inactive substance (placebo).
If the vaccine is effective, it may help reduce illness and health-care costs
among older people. For more information on the study, call 1-877-841-6251,
or visit www.niaid.nih.gov/shingles.
--E.Z.
