Vol. 1, Issue 7, Part D (2015)

Abstract
Herpes zoster, or shingles, is a localized disease characterized by unilateral radicular pain and a vesicular rash limited to the area of skin innervated by a single dorsal root or cranial sensory ganglion. Whereas varicella, or chickenpox, results from primary exogenous varicella-zoster virus (VZV) infection, herpes zoster is caused by reactivation of endogenous VZV that has persisted in latent form within sensory ganglia following an earlier episode of chickenpox. In contrast to recurrent herpes simplex, herpes zoster is commonly associated with severe pain: prodromal pain often precedes the rash by several days; pain usually accompanies the dermatomal rash of herpes zoster; and many debilitating complications like postherpetic neuralgia (PHN). The incidence and severity of herpes zoster and its complications increase with age in association with an age-related decline in cell-mediated immunity to VZV.