varicella-zoster virus (VZV) is the virus that causes chickenpox,
shingles and post-herpetic neuralgia (PHN).
The varicella-zoster virus (VZV)
first strikes as chickenpox
, a highly contagious
disease affecting 95 percent of Americans by age 18, or four million
individuals annually. Although it is commonly regarded as a mild childhood
illness, chickenpox is a significant disease. It usually causes fever,
discomfort, loss of appetite, headache and skin lesions, which can leave
scars. But it can also lead to hospitalization and, in rare instances,
Bacterial skin infections are the most common chickenpox-related complications
and they are increasing in number and severity. Other complications
include inflammation of the brain (encephalitis) and pneumonia, although
these are rare in otherwise healthy people.
According to the Centers for Disease Control and Prevention (CDC),
each year in the U.S., chickenpox results in: the hospitalization
of nearly 11,000 individuals, the majority of whom are otherwise healthy,
and two-thirds of whom are children; and 105 deaths.
Chickenpox is now preventable. In March 1995, following more than a
decade of development and testing, the U.S. Food and Drug Administration
approved the country's first chickenpox vaccine for use in children
and adults who have not had chickenpox. The FDA concluded that the vaccine
is safe and effective.
Shingles & PHN
an episode of chickenpox, the varicella-zoster virus lies dormant, or
asleep, in nerve tissues. However, in an estimated one out of seven
people over the course of an 85-year lifetime, the virus can reappear
as shingles or herpes zoster
. Shingles is an outbreak of a rash
or blisters on the skin that can be very painful. The rash and pain
usually occur in a band on one side of the body, or clustered on one
side of the face.
In otherwise healthy individuals, shingles may disappear without major
consequence in two to four weeks. But the risk of complications from
shingles increases with age, weakened immunity (the body's ability to
ward off disease) and delay or lack of treatment. Complications include
post-herpetic neuralgia (PHN)
, which can cause debilitating pain
that persists for months or even years after the shingles rash has healed.
The pain of PHN may be sharp, piercing, throbbing or stabbing, and it
may extend beyond the area of the original shingles eruption. The skin
may be unusually sensitive to even the lightest touch (as from clothing),
to the smallest breeze, and to changes in temperature (either hot or
In addition to PHN, complications affecting vision and/or hearing are
possible if shingles appears on the face. For instance, if shingles
affects the eye (ophthalmic shingles)
, the cornea can become
infected, resulting in temporary or permanent blindness. In patients
with severely weakened immunity, the shingles virus can also spread
to internal organs, affecting the lungs, central nervous system and
The National Shingles Foundation estimates that nearly one million individuals
are afflicted by shingles each year in the U.S. alone
. It is most
common among people over the age of 50, as well as among those who have
conditions or are undergoing medical treatments that weaken their immune
systems. These include: HIV infection; chemotherapy or radiation therapy;
corticosteroids; transplant operations; and possibly stress.
Currently, shingles cannot be prevented. However, a major study is underway
to determine whether vaccination can decrease the incidence and/or severity
of shingles and its complications in adults 60 years of age and older
who have had natural chickenpox.
Antiviral drugs can lessen the duration of shingles and lower the
risk for PHN if taken within 72 hours after the appearance of the
rash. PHN is treated by a variety of pain-relieving approaches: nonsteroidal
anti-inflammatory drugs, narcotic analgesics and specific medications
for nerve injury-related pain, including certain medications best
known for treating depression. In 1999, the FDA approved a lidocaine
skin patch for PHN pain.
The effectiveness of treatment for PHN varies widely among patients.
If you develop PHN, you may wish to consult a physician who specializes
in the treatment of pain; one option is the attending neurologist or
anesthesiologist of a leading hospital in your area.
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