Principles & Practice of Pain Medicine > Part V. Pain Syndromes > A. Neuropathic Pain > Chapter 40. Acute Herpes Zoster and Postherpetic Neuralgia P. Prithvi Raj

Acute Herpes Zoster

"Acute herpes zoster, commonly called shingles, is an acute infectious viral disease that primarily affects the posterior spinal root ganglia of the spinal nerves. A single posterior spinal root ganglion or a small number of adjacent ones may be affected, usually on the same side. The corresponding ganglia of the cranial nerves also may be involved similarly. The causative virus, varicella-zoster, belongs to a DNA group of viruses that is host specific. The same virus produces chickenpox or varicella in children and young people.Herpes zoster most frequently occurs in adults who previously have had chickenpox. It is thought that the virus remains dormant in the dorsal root ganglia until, many years later, it is reactivated and produces herpes zoster. The decrease in immunity that permits the reactivation may be caused by infection or malignancy, or it may occur in the iatrogenically immunosuppressed patient. The impact of stress on varicella-zoster virus has not been well studied, but major depression has been associated with markedly decreased varicella-zoster virus–specific cellular immunity.¹ Patients experiencing stress during a zoster episode are more likely to have more severe pain, increasing their risk of postherpetic neuralgia.² Patients with herpes zoster occasionally relate a history of recent contact with the virus exogenously; but it is rare, if ever, that an infection so develops. The incidence of herpes zoster does not increase during seasonal chickenpox epidemics...."