Medicine for the Outdoors
Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.See all posts »
Zostavax for Herpes Zoster (Shingles)
Zostavax is a new vaccine to reduce the risk for herpes zoster (HZ), commonly known as “shingles,” in elder adults. It is given as a single subcutaneous injection.Having encountered shingles in emergency department patients regularly over the years, and in a few unfortunate victims during adventure travel, I can state affirmatively that shingles can be quite debilitating. We are keeping our fingers crossed that this new vaccine will be as effective in the general population as it was demonstrated to be in a study population.
HZ is caused when varicella-zoster virus (VZV), which causes chickenpox, is reactivated from a latent or dormant (inactive) state. After an infection with VZV, a person can retain the virus, quite commonly in nerve tissue. While most cases of reactivation can not be linked definitively to a specific cause, some cases of viral reactivation are felt to be related to physiological stresses, such as extreme fatigue, suppression of the immune system, concurrent cancer, or intense exposure to environmental extremes (sunlight or heat), or significant emotional stress. Shingles is a situation wherein the virus becomes active in the distribution of one or more nerve roots, which are branches off the spinal cord.
In a typical episode of shingles, the victim (most commonly a person older than 60 years of age – but this is an affliction certainly seen in younger individuals as well) notes symptoms prior to eruption of the rash. These include a sensation of tingling or burning in the skin that will soon become reddened and blistered. Sometimes the tingling and burning can become sharply and intensely painful prior to appearance of the rash. When the skin is examined at this stage, it may appear normal.
Within a few days of the abnormal sensations, the skin reddens and blisters, with clusters of fluid-filled skin bubbles corresponding to the distribution of the particular involved nerve(s). During this stage, pain may be very severe. If the face, mouth, eyes, or genitals are involved, a person may have difficulty with eating, vision, or urinating.
After a case of HZ, the victim may suffer the complication of postherpetic neuralgia (PHN), which may cause debilitating pain for months. PHN is often defined as severe pain associated with HZ that persists for 90 days after the initial onset of pain.
Treatment for acute HZ includes prompt administration of an antiviral drug, such as famciclovir or acyclovir. However, this treatment is not curative, but rather, shortens the duration of the rash and pain. Furthermore, the antiviral agents do not seem to prevent the occurrence of PHN.
Zostavax is a vaccine from the pharmaceutical company Merck composed of live attenuated VZV. In one large study, vaccine administration in an elder population decreased the incidence of shingles by 51% and also diminished the duration and severity of pain and discomfort in recipients of the vaccine who developed shingles, as compared to non-immunized individuals. Immunized individuals also showed a lower incidence of postherpetic neuralgia, although this effect may largely be attributed to the decreased incidence of HZ. The beneficial effects declined as the age of the recipients rose, with the youngest age being 60 years, and the oldest begin greater than 80 years. This observation may have to do with declining immune response (to the vaccine) with increasing age.
As physicians and patients accumulate more experience with the vaccine, it may become an important immunization for elders as they prepare to embark on wilderness adventures, where an episode of HZ might at best be inconvenient, and at worse, become a medical cause for discontinuation of the trip.
Tags: Zostavax, herpes zoster, shingles, wilderness medicine, outdoor medicine, healthline
photo by Paul Auerbach
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