Page 207 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 6-32 Infectious Diseases

VARICELLA ZOSTER WITH KERATITIS

HERPES ZOSTER (SHINGLES) Herpes zoster.
(Continued) Painful vesicles,
erosions with
an erythematous
base
Simultaneous involvement of the facial and vestibular
nerves is not infrequent and has been termed the
Ramsay Hunt syndrome. These two nerves originate in
close proximity to each other, and reactivation of VZV
within the geniculate ganglion may involve both these
nerves. This can lead to hearing loss and motor nerve
loss due to involvement of the vestibular and the facial
nerve, respectively. The ear and the anterior tongue
develop the vesiculation seen in routine VZV infec-
tions. The motor loss may mimic Bell’s palsy, and
hearing loss may be permanent. Other cranial nerves
have been reported to be affected in Ramsay Hunt
syndrome, but the seventh and eighth nerves are those
most frequently affected by far.
Scarring may be a severe sequela of this infection,
and it can be made worse by bacterial superinfection.
The presence of any honey-colored crusting or expand-
ing erythema outside the dermatome should suggest the Dendritic keratitis
possibility of secondary impetigo or cellulitis. Prompt (herpes simplex)
recognition and therapy are required to help prevent demonstrated by
serious, disfiguring scarring. fluorescein
The diagnosis is made clinically, and the Tzanck test
can confirm the diagnosis. The presence of multinucle-
ated giant cells on a Tzanck preparation taken from
a vesicular rash in a dermatomal distribution confirms
the diagnosis. Viral culture can be performed, but is
not cost-effective. Direct immunofluorescent antibody
testing (DFA) is a rapid method to determine the viral
cause, but it is expensive and is rarely needed in these
cases.
Histology: Skin biopsies are not needed for diagnosis
of this infection. If one were to biopsy a vesicle, bal-
looning degeneration of the keratinocytes would be
present. This ballooning degeneration leads to the
vesiculation and bulla formation. Multinucleated giant
cells can be seen at the base of the blister. A mixed
dermal inflammatory infiltrate is present.
Pathogenesis: Any individual previously infected with
VZV in the form of chickenpox is predisposed to
develop herpes zoster later in life. Most cases occur
with advancing age, as cell-mediated immunity tends to
wane with time. The virus remains latent in the nerve Acute keratitis
ganglia until it reactivates. The ability to reactivate and Technique of applying fluorescein (ciliary injection,
the exact signal for reactivation are unknown. Once the strip in previously anesthetized eye irregular corneal surface)
virus reactivates, it begins to replicate and to cause
necrosis of the affected nerve cells. The virus travels
along the cutaneous sensory nerves and eventually
affects the skin that is innervated by the nerve root decrease the risk of postherpetic neuralgia, but large the number of cases of herpes zoster and the fre-
where the virus became reactivated. studies have thus far shown inconclusive data to support quency of postherpetic neuralgia in those who do
Treatment: Treatment with antiviral medications this approach. The therapy has the best chance of develop herpes zoster after vaccination. As with all
from the acyclovir family should be instituted immedi- changing the course of the disease if given within the live vaccines, its use in immunosuppressed patients is
ately. The sooner therapy is started, the better is the first 72 hours after the onset of disease symptoms. contraindicated.
chance of decreasing the length of disease. Therapy A live attenuated zoster vaccine for the pre vention Currently, the treatment of postherpetic neuralgia is
may also decrease the incidence of postherpetic neural- of herpes zoster is being given to patients older than not optimal. Amitriptyline, gabapentin, lidocaine
gia. The use of oral corticosteroids in conjunction with 60 years of age. This vaccine has been shown to patches, pregabalin, anticonvulsants, and opioids are all
the antiviral medication has been advocated to help boost natural immunity against VZV and to decrease used with varying success.

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