Prevention of Post-herpetic Neuralgia from Dream to Reality: A Ten-step Model

Abstract

Herpes zoster (HZ) is a painful, blistering skin eruption in a dermatomal distribution caused by reactivation of a latent varicella zoster virus in the dorsal root ganglia (DRG). Post-herpetic neuralgia (PHN) is the most common complication of acute herpes zoster (AHZ). Severe prodrome, greater acute pain and dermatomal injury, and the density of the eruption are the risk factors and predictors for developing PHN. PHN has a substantial effect on the quality of life; many patients develop severe physical, occupational, social, and psychosocial disabilities as a result of the unceasing pain. The long-term suffering and the limited efficacy of the currently available medications can lead to drug dependency, hopelessness, depression, and even suicide. Family and society are also affected regarding cost and lost productivity. The pathophysiology of PHN remains unclear. Viral reactivation in the dorsal root ganglion and its spread through the affected nerve result in severe ganglionitis and neuritis, which induce a profound sympathetic stimulation and vasoconstriction of the endoneural arterioles, which decreases the blood flow in the intraneural capillary bed resulting in nerve ischemia. Our rationale is based on previous studies which have postulated that the early interventions could reduce repetitive painful stimuli and prevent vasospasm of the endoneural arterioles during the acute phase of HZ. Hence, they might attenuate the central sensitization, prevent the ischemic nerve damage, and finally account for PHN prevention. The author introduces a new Ten-step Model for the prevention of PHN. The idea of this newly suggested approach is to increase the awareness of the health care team and the community about the nature of HZ and its complications, especially in the high-risk groups. Besides, it emphasizes the importance of the prompt antiviral therapy and the early sympathetic blockades for preventing PHN. Key words: Acute herpes zoster, prevention, post-herpetic neuralgia, sympathetic blockade, tenstep model