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Herpes zoster, colloquially known as
shingles, is
the reactivation of varicella zoster virus,
leading to a crop of painful blisters over
the area of a dermatome. Shingles /
herpes zoster occurs very
rarely in children and adults, but its
incidence is high in the elderly, as well as
in any age group of immunocompromised
patients. Treatment for shingles /
herpes zoster is generally with
acyclovir. Many develop a painful condition
termed postherpetic neuralgia.
Signs and
Symptoms of Shingles
Often, the
pain is the first shingles /
herpes zoster symptom. Then 2-3
crops of red lesions develop, which
gradually turn into small blisters filled
with serous fluid. With shingles / herpes
zoster, the
symptoms of a feeling of unwellness often
occurs.
As long as the blisters have not dried
out, Herpes Zoster / Shingles patients may transmit
varicella zoster virus to
others. This could lead to chickenpox in
people (mainly young children) who are not
yet immune for varicella zoster virus.
Shingles blisters are unusual in that
they only appear on one side of the body.
That is because the chickenpox virus can
remain dormant for decades, and does so
inside the spinal column or a nerve fiber.
If it reactivates as shingles / herpes
zoster, it affects
only a single nerve fiber, or ganglion,
which can radiate to only one side of the
body. The blisters therefore only affect one
area of the body and do not cross the
midline. Shingle blisters are most common on the torso,
but can also appear on the face (where they
are potentially hazardous to vision) or
other parts of the body.
Diagnosis of Shingles
The diagnosis
of shingles / herpes zoster is visual - very few other
diseases mimic herpes zoster. In case of
doubt, fluid from a blister may be analysed
in a medical laboratory.
Pathophysiology of
Shingles
The causative agent for
herpes zoster (shingles) is
varicella zoster virus (VZV). Most people
are infected with this virus as a child, as
it causes chickenpox. The body eliminates
the virus from the system, but it remains
dormant in the ganglia adjacent to the
spinal cord or the ganglion semilunare
(ganglion Gasseri) in the cranial base.
Generally, the immune system
suppresses
reactivation of the varicella zoster virus. In the elderly,
whose immune response
generally tends to
deteriorate, as well as in those patients
whose immune system
is being suppressed,
this process fails. (Some researchers
speculate that sunburn and other, unrelated
stresses that can affect the
immune system
may also lead to viral reactivation.) The
shingle virus starts replicating in the nerve cells,
and newly formed viruses are carried down the
axons to the area of skin served by that
ganglion (a dermatome). Here, the virus
causes local inflammation in the skin, with
the formation of blisters.
The pain characteristic of
herpes zoster / shingles
is thought to be due to irritation of the
sensory nerve fibers in which the virus
reproduces.
Transfer Factor helps your
immune system
function properly to protect your body.
Therapy for Shingles
Aciclovir (an antiviral drug)
inhibits replication of the viral DNA,
and is used both as prophylaxis (e.g.
in patients with
AIDS) and as therapy
for shingles / herpes zoster. Other antiviral are valaciclovir and famciclovir. Steroids
are often given in severe cases of
shingles.
The long term complication
postherpetic neuralgia may cause
persistent pain that lasts for years.
Pain management
of shingles is difficult as
conventional analgesics may be
ineffective. Alternative agents are
often used, including tricyclic
antidepressants, anticonvulsants,
and/or topical agents.
Shingles
Prognosis
The rash and pain
of shingles usually subside
within 3 to 5 weeks. Sometimes serious
effects including partial facial
paralysis (usually temporary), ear
damage, or encephalitis may occur.
Shingles / herpes zoster on the upper half of the face
(the first branch of the trigeminal
nerve) may result in eye damage and
require urgent ophthalmological
assessment. |
