Shingles
Or Herpes Zoster Introduction: The same varicella-zoster
virus that causes chickenpox also causes shingles, which involves only a segment
of the skin. In a child with no antibodies to the chickenpox virus the virus travels
to the whole skin surface causing the typical chickenpox lesions all over the
body. In an adult who had prior exposure to the varicella-zoster virus there is
a latent infection in the dorsal root ganglia of the spinal cord. It remains
confined to these cells until there is a change of the immune status. Factors
such as stress weakening the immune system (often in college or university students)
or a weakened immune system due to AIDS or due to immunosuppression (in transplant
patients or patients who had chemotherapy for cancer) can allow the varicella-zoster
virus to migrate along the nerve fibers to the associated skin segment. It is
there where the disease breaks out and affects one dermatome on one side of the
body. This is called "shingles" in common language or "herpes zoster"
in the medical language. Shingles Symptoms: Usually
there is a prodromal stage where there is shooting pain in the skin dermatome,
which will be breaking out later in the shingles rash. The pain period usually
lasts about 2 or 3 days. Then redness of the skin appears from the inflammation
of the virus. There is hypersensitivity to touch in the affected dermatome and
multiple skin blisters (vesicles) appear in the same region. Most commonly it
is in the skin of the lumbar and thoracic region that is affected and the rash
is confined to one side. Typically, the rash lasts for about 4 to 5 days.
Most often the patients get herpes zoster only once, only less than 4% of patients
might get a recurrence of it. However, these patients warrant a thorough workup
for cancer that might be hidden, but weaken the immune system. Here is a link
to a picture
of shingles (use the back arrow in your left upper screen to return
to this page). There are two special cases that warrant mentioning:
A) In ophthalmic herpes zoster (=herpes
zoster ophthalmicus) one of the facial branches (ophthalmic, maxillary or mandibular
branch of the trigeminal nerve) is affected. If the ophthalmic branch is affected
the varicella-zoster virus will often affect the cornea and there is a danger
of corneal perforation. An emergency assessment and treatment by an ophthalmologist
is required to abort the disease. B) Ramsey Hunt's syndrome
or herpes zoster oticus is due to invasion of the varicella-zoster
virus of the 8th cranial nerve and a ganglion of the facial nerve. This causes
severe pain in the ear, dizziness (vertigo), hearing loss and palsy of the affected
facial nerve. Herpes zoster vesicles can be seen in the ear canal. Two thirds
of the tongue towards the tip of the tongue can experience a loss of taste. Signs
of mild meningitis and encephalitis and involvement of other cranial nerves can
be found associated with this. Diagnosis and prognosis: The
diagnosis is mostly made clinically although in occasional cases special blood
tests (ELISA titer) might have to be done to confirm the diagnosis. This
involves that blood for serum is drawn early into the disease and at the time
of complete recovery. A rise of specific antibodies detected this way will confirm
the diagnosis. Most of the time the prognosis is good meaning that the
patient recovers without any consequences. However, with ophthalmic herpes
zoster not infrequently postherpetic neuralgia develops, which is a painful
condition in the affected dermatome with chronic pain and exaggerated skin hypersensitivity.
With herpes zoster oticus loss of taste of the front 2/3 of the tongue
could stay permanent, as can the loss of hearing on the affected side. Shingles
treatment: There has been a breakthrough with the introduction
of acyclovir (brand name: Zovirax) with respect to the recovery time from shingles
as well as with respect to the recovery from chickenpox. Often the overall
time of disease is cut in half and complications such as postherpetic neuralgia
or bacterial superinfection are diminished significantly. Similarly, the other
newer agents such as valacyclovir (brand name: Valtrex) and famciclovir (brand
name: Famvir) are equally effective. Ophthalmic herpes zoster:
As mentioned above treatment of ophthalmic herpes zoster should be supervised
by an ophthalmologist. Frequent examinations with a slit lamp and topical applications
of antiviral eye drops in combination with oral antiviral therapy are essential.
If the eye-specialist sees keratitis (involvement of the cornea of the eye) treatment
with topical corticosteroid eye drops would be given. This is quite different
from herpes simplex keratitis, where topical corticosteroids are contraindicated
for fear of perforation of the cornea. Herpes zoster oticus:
Treatment of herpes zoster oticus should be supervised by an ENT specialist,
although there are not too many options for effective treatment. High doses of
oral prednisone are given as early as possible to control inflammation. Antiviral
antibiotics are also administered to shorten the overall duration of the disease.
However, no evidence is available to show reliably that hearing loss or loss of
tongue sensitivity would be improved by these therapeutic measures. Decompression
surgery to free the sensory branch of the facial nerve sometimes improves facial
paralysis. Dizziness is treated symptomatically with diazepam, pain is treated
with codeine or other narcotics. Aids and herpes zoster:
In AIDS patients who developed herpes zoster ongoing antiviral
suppression therapy must be considered as otherwise herpes zoster will reoccur
repeatedly. |
