Postherpetic neuralgia: epidemiology, pathophysiology, and pain management pharmacology

Abstract

Herpes zoster, also known as shingles, is a distinctive clinical condition caused by the reactivation of latent varicella zoster (chickenpox) virus following an initial infection. Approximately 1 million cases of herpes zoster occur annually in the US, and one in every three people develops herpes zoster during their lifetime. Postherpetic neuralgia is a neuropathic pain syndrome characterized by pain that persists for months to years after resolution of the herpes zoster rash. It stems from damage to peripheral and central neurons that may be a byproduct of the immune/inflammatory response accompanying varicella zoster virus reactivation. Patients with postherpetic neuralgia report decreased quality of life and interference with activities of daily living. Approaches to management of postherpetic neuralgia include preventing herpes zoster through vaccination and/or antiviral treatment, and administering specific medications to treat pain. Current guidelines recommend treatment of postherpetic neuralgia in a hierarchical manner, with calcium channel α2-δ ligands (gabapentin and pregabalin), tricyclic antidepressants (amitriptyline, nortriptyline, or desipramine), or topical lidocaine patches as first-line drugs. The safety and tolerability of pharmacologic therapies for pain are important issues to consider as postherpetic neuralgia affects primarily an older population. Patients should be educated on appropriate dosing, titration if applicable, the importance of adherence to treatment for optimal effectiveness, and possible side effects. Health-care professionals play a key role in helping to ameliorate the pain caused by postherpetic neuralgia through early recognition and diligent assessment of the problem; recommending evidence-based treatments; and monitoring treatment adherence, adverse events, responses, and expectations. Nurse practitioners are especially crucial in establishing communication with patients and encouraging the initiation of appropriate pain-relieving treatments.

Manipulation of the Innate Immune Response by Varicella Zoster Virus

“…The most common complication of herpes zoster is PHN which is a pain persisting for months to years after herpes zoster rash resolution (41). PHN occurs in 5-30% of people who experience herpes zoster and the prevalence and severity increases dramatically with advancing age (42). To date the mechanisms underpinning PHN are not yet fully understood.…”

Coadministration of probenecid and cimetidine with mirogabalin in healthy subjects: A phase 1, randomized, open‐label, drug–drug interaction study

“…DPNP is a common complication of diabetes affecting up to 50% of patients with diabetic neuropathy in the USA 2. PHN, a common complication of herpes zoster (shingles), affects up to 20% of patients with herpes zoster 3.…”

World Workshop on Oral Medicine VII: Burning mouth syndrome: A systematic review of disease definitions and diagnostic criteria utilized in randomized clinical trials

“…However, the presence of a trigger may provide insight into a physiological response to a traumatic insult that is unique compared with those who do not experience an initial triggering event (Jaaskelainen, ; Jaaskelainen & Woda, ). For example, burning discomfort occurs in persons who develop PHN; however, a majority of persons who develop herpes zoster infection do not experience PHN suggesting unique physiological responses in subsets of the affected patients (Mallick‐Searle, Snodgrass, & Brant, ). Accordingly, triggering events should be more carefully considered in persons suffering from BMS.…”