11.18 Herpes Zoster (Shingles)
==============================

agk's Library of Common Simple Emergencies

Presentation: Patients complain of pain, 
paresthesia, or an itch that covers a specific 
dermatome and then develops into a characteristic 
rash. Prior to the onset of the rash, zoster can 
be confused with pleuritic or cardiac pain, 
cholecystitis, or ureteral colic. Approximately 
3-5 days from the onset of symptoms, an eruption 
of erythematous macules and papules will appear, 
first posteriorly then spreading anteriorly along 
the course of the involved nerve segment. In most 
instances grouped vesicles will appear within the 
next 24 hours. Herpes zoster most often occurs in 
the thoracic and cervical segments.

What to do:
-----------

- Prescribe acyclovir (Zovirax) 800mg q4h (five 
    times a day, skip a dose at night) or 
    famiclovir (Famvir) 500mg tid x7d.
- Prescribe analgesics appropriate for the level 
    of pain the patient is experiencing. 
    Anti-inflammatory medications may help, but 
    narcotics are often required (e.g., Percocet 
    q4h).
- Cool compresses with Burow's solution will be 
    comforting (e.g Domeboro powder, 2 pkts in 1 
    pint of water).
- Dressing the lesions with gauze and splinting 
    them with an elastic wrap may also help bring 
    relief.
- Secondary infection should be treated with 
    povidone-iodine (Betadine) ointment or 
    systemic antibiotics.
- Ocular lesions should be evaluated by an 
    ophthalmologist and treated with topical 
    ophthalmic corticosteroids. Although topical 
    steroids are contraindicated in herpes 
    simplex keratitis, because they allow deeper 
    corneal injury, this does not appear to be a 
    problem with herpes zoster ophthalmicus. If 
    the rash extends to the tip of the nose, the 
    eye will probably be involved, because it is 
    served by the same ophthalmic branch of the 
    trigeminal nerve.

What not to do:
---------------

- Do not prescribe systemic steroids to prevent 
    post herpetic neuralgia, especially for 
    patients at high risk, i.e., with latent 
    tuberculosis, peptic ulcer, diabetes 
    mellitus, hypertension, and congestive heart 
    failure.

Discussion
----------

Zoster results from reactivation of latent herpes 
varicella/zoster (chickenpox) virus residing in 
dorsal root or cranial nerve ganglion cells. 
Two-thirds of the patients are over 40 years old. 
This is a self-limiting, localized disease and 
usually heals within 3-4 weeks. Postherpetic 
neuralgia in patients over 60 years old, however, 
can be an extremely painful, recurrent misery. 
Before the availability of anti-viral agents, the 
best prophylaxis was systemic corticosteroids, 
but these have not been shown to improve outcome 
when added to a week of anti-viral treatment.

References:
-----------

- Wood MJ, Johnson RW, McKendrick MW, Taylor J, 
    Mandal BK, Crooks J: A randomized trial of 
    acyclovir for 7 days or 21 days with and 
    without prednisolone for treatment of acute 
    herpes zoster. *N Eng J Med* 1994;330:896-900.

 ----------------------------------------------------
 from Buttaravoli & Stair: COMMON SIMPLE EMERGENCIES
 Longwood Information LLC 4822 Quebec St NW Wash DC
 1.202.237.0971 fax 1.202.244.8393 electra@clark.net
 ----------------------------------------------------