Postherpetic Neuralgia

Excerpt

Postherpetic neuralgia (PHN) is the most common long-term complication of varicella-zoster virus (VZV) reactivation, also known as human herpesvirus-3 (HHV-3). This reactivation of the dormant VZV is known as herpes zoster or shingles. VZV is the causative agent for the childhood condition varicella, colloquially known as chickenpox. Before the advent of vaccination in the late 1990s and early 2000s, upward of 90% of American adults would test seropositive for VZV. Although this number and the percentage of adults who go on to develop herpes zoster and PHN may decrease in the coming generations, PHN is currently a topic of clinical importance.

The hallmark of PHN is a lancinating/burning pain in a unilateral dermatomal pattern that persists for three or more months after the onset of a herpes zoster (HZ) outbreak. Two universally accepted risk factors for HZ are increasing age and immunosuppression, and because HZ is a prerequisite for the development of PHN, the elderly and infirm are commonly afflicted. The most successful treatments are multi-modal, with some researchers/clinicians focusing on prevention in high-risk populations rather than cure because of the debilitating and often refractory nature of PHN in already fragile patient populations.