Treating Herpes Zoster and Postherpetic Neuralgia

Michael C. Rowbotham, MD California Pacific Medical Center Research Institute Department of Anesthesia, UCSF School of Medicine San Francisco, Calif., USA Email: [email protected] P ostherpetic neuralgia (PHN) is t e most frequent chronic complication of herpes zoster ( hingles). Herpes zoster (HZ) represents a reactivation of the varicella zo ter vi us (VZV), a ubiquitous, highly neurotropic, exclusively human α-herpesvirus. rimary infection causes varicella (chickenpox), after which VZV becomes latent in sensory ganglia along the entire neuraxis. With the decline in VZV-specific cell-mediated immunity in elderly and immunocompromised individuals, VZV reactivates to cause HZ, characterized by a painful maculopapular or vesicular rash in all or part of the skin territory innervated by a single dorsal root ganglion. The most common site of HZ is thoracic, comprising about half of all cases, followed by trigeminal (usually the ophthalmic branch), cervical, and lumbar distributions. HZ generally resolves within a few weeks, but a minority of patients experience pain (PHN) persisting for months, years, or even a lifetime.