Postherpetic neuralgia in Europe: The scale of the problem and outlook for the future

Abstract

Herpes zoster (HZ; shingles) is a viral disease characterized by a painful unilateral rash involving one or two adjacent dermatomes. HZ results from reactivation of the varicella zoster virus (VZV) acquired during chickenpox. Following this primary VZV infection, the virus establishes latency in sensory nerve ganglia, until it reactivates decades later. The rash usually heals within 2-4 weeks, but some individuals experience residual neuropathic pain, known as postherpetic neuralgia (PHN), for months or even years, which can seriously impact their quality of life. We reviewed the epidemiological data for PHN in Europe since 2000 after the introduction of antiviral drugs. The overall lifetime risk for HZ was 23-30% and increased to 50% in those >80 years old. Defining PHN as pain persisting 3 months after rash onset, between 10% and 30% of patients with HZ developed PHN; this increased to 60-70% in those age ≥60 years. Some trials have reported that antiviral agents given soon after rash onset may prevent PHN. Vaccination programs with a zoster vaccine have been shown to prevent PHN, particularly in older patients. The various definitions used for PHN in different studies make it difficult to acquire a meaningful measurement of the true burden of PHN. In addition, comparisons between various studies and the prevalence and incidence data from different countries are difficult, because of this heterogeneity. This article provides a balanced overview of the important clinical and epidemiological studies carried out with respect to the definition, prevention, and treatment of this debilitating condition. Copyright © 2013, Asia Pacific League of Clinical Gerontology & Geriatrics. Published by Elsevier Taiwan LLC. All rights reserved.