After a bout of the chicken pox, the varicella-zoster virus lies dormant in the body. In people with normal functioning immune systems keep the virus at bay the rest of their lives. People who have a compromised immune system due to chronic illness, advanced age, HIV or AIDS cannot fight off the virus. In these people, it re-emerges and settles in a group of nerves causing a painful case of the shingles.
Clinical findings
Neuralgia or nerve pain presents up to 48 hours before the vesicular lesions erupt. The virus attacks one dermatome. Dorland's Illustrated Medical Dictionary, 31st edition defines a dermatome as a linear group of nerve fibers that join together at the same place in the spinal cord. The favored dermatome runs from the navel area to the center of the back on one side only. Less frequently, the virus chooses the trigeminal nerve that innervates the face in three places. Another finding appears as swollen and tender lymph nodes in the region of the outbreak.
Complications
Current Diagnosis and Medical Treatment, states the pain of herpes zoster persists well after the lesions disappear. Referred to as postherpetic neuralgia, it often afflicts those over 60 and those whose outbreak hits the trigeminal nerve. In the trigeminal nerve, one nerve branch innervates the eye. When the virus settles in that nerve branch, it can impair vision. Temporary vision impairment often leads to permanent blindness. The skin eruptions leave scars in their wake. Treatment in the early part of the disease lessens the chance of postherpetic pain.
Prevention
According to Current Diagnosis and Treatment, a live effective herpes zoster vaccine became available in 2007. Primarily administered for prevention the vaccine also works to reduce neuralgia when given in the postherptic stage. The vaccine targets people over 60 because they run a higher risk of having the trigeminal nerve shingles. Another factor for giving the vaccine to this age group is, this population's tendency to have lengthy debilitating postherpetic neuralgia.
Treatment
For patients who contract herpes zoster, it remains important that they get treatment early in the disease to lessen the likelihood of a prolonged aftermath. Antivirals such as acyclovir, famcylovir and valcyclovir temper but do not cure the virus. Patients should stay well hydrated while taking this class of drugs. Corticosteroids reduce acute pain but immunocompromised people must avoid there. They receive the antiviral therapy only. For the lingering pain of shingles, an assortment of topical treatments and analgesics exist. Regional nerve blocks temporarily deaden the affected dermatome in the worst cases of pain.
Prognosis
According to Current Diagnosis and Medical Treatment 2010, the eruption of the rash lasts for two to three weeks. It runs its course in about six weeks. Generally it occurs only once in a lifetime but in rare cases it can recur. Current Diagnosis and Medical Treatment, 2010 further states in 2% to 3% of the cases, temporary motor palsy appears.
References
- Current Medical Diagnosis and Treatment; Stephen J. McPhee and Maxine A. Papadakis; 2010
- Dorland's Illustrated Medical Dictionary, 31st ed.; Sanders Elsevier, publisher; 2007
