Efficacy of Corticosteroids in the Prevention of Post Herpetic Neuralgia

 Efficacy of Corticosteroids in the Prevention of Post Herpetic Neuralgia

Abstract

The available empirical and research evidence suggests that Postherpetic neuralgia (PHN) is a typical serious medical complication associated with herpes zoster (HZ; Chen 2010). Notable, it has been reported that anti-inflammatory properties of corticosteroids could be beneficial in the prevention of PHN (Chen 2010). The core objective of this review was to examine the effectiveness of corticosteroids in the prevention of PHN.

The researchers evaluated the studies for the relevant randomised controlled trials (RCTs) of corticosteroids for PHN prevention in Google Scholar, ClinicalTrials.gov, EMBASE, MEDLINE, and Cochrane Library databases. The timeframe was restricted to the studies published between 3 February 2010 and March 26, 2018. The rationale for this restriction was to determine whether recent studies have contributed similar or conflicting empirical evidence to Chen’s (2010) Cochrane review. The present review included all the RCTs that involved administration of corticosteroids in different forms, including intravenous or intramuscular, to patients diagnosed with herpes zoster (HZ). We identified relevant articles, obtained the data and three independent reviewers evaluated each RCT’s quality. Lack of consensus in data extraction was addressed through discussion. Assessment of the five articles included in the present review showed that a treatment intervention involving corticosteroids does not significantly prevent or mitigate the pain that is associated with PHN.   

Background

Herpes zoster (HZ) is typically described as a debilitating and painful condition “caused by a reactivation of the varicella-zoster virus (VZV) from a latent infection of sensory ganglia" (Johnson 2010). Mainly, the symptoms of this disease are often not specific and can range from an intense burning sensation to itching (Jeon 2015). Research has demonstrated varicella-zoster virus acquired during chicken pox contributes towards the reactivation of HZ, which notably is the major varicella infection (Chen 2010). It is important to note that empirical research and evidence has also revealed that the latent VZV reactivation from the dorsal ganglia is usually responsible for the traditional dermatomal rash and pain that is associated with HZ (Chen 2010; Gershon 2010; Johnson 2010; Puri 2011).

The vesicular skin rash in the affected dermatome, which is often accompanied by acute pain, is considered to be the acute phase of the HZ condition (Johnson 2010; Gan 2013). The acute phase of HZ is often described as occurring up to 30 days after the onset of the rash (Jeon 2015). The patients who later develop chronic disease usually experience a subacute phase that lasts between 30 and 90 days after the onset of the vesicular skin rash in the affected dermatome (Johnson 2010). Compared to the other side effects associated with HZ, PHN is reported to be the most troublesome (Jeon 2015). Nevertheless, PHN often exhibits a considerable degree of resistance to the existing analgesic treatments, for example, anticonvulsants, opioids, antidepressants, and topical agents, such as capsaicin cream and lidocaine patches, and thus it can persist for many years (Jeon 2015).  

It is believed that the early diagnosis and treatment of acute HZ with suitable antiviral agents reduces its severity and more importantly, mitigates the risk of PHN (Whitley 2010; Jeon 2015). It has been suggested that the prophylactic vaccination against VZV could potentially be the ideal way to prevent as well as minimize the incidence of PHN and HZ (Jeon 2015). On the other hand, corticosteroids possess a potent anti-inflammatory action that can minimize nerve damage and thereby prevent or relieve the pain in individuals that have been diagnosed with PHN (Chen 2010; Massengill 2014). Adding corticosteroids to treatment with acyclovir reduces the pain of HZ and increases the pace at which skin lesions heal (Fashner 2010). In fact, it is recommended that combination therapy of antivirals and corticosteroids should be used on older patients without contra-indications.

In a 2010 Cochrane review, it was observed that although corticosteroids possess anti-inflammatory effects that are capable of reducing nerve damage and the risk to PHN, there is no significant distinction between placebo and corticosteroids in preventing PHN six months after the onset of the common dermatomal rash and pain associated with HZ (Chen 2010). It is worth noting that the treatment of HZ has three key objectives: 1) prevention of the PHN, 2) treatment of the acute pain that is openly associated with HZ, and 3) treatment of the acute viral infection (Chen 2010). Research and empirical evidence have confirmed that antiviral agents and adjunct medications, including oral corticosteroids, tricyclic antidepressants, and opioid analgesics, can relieve the pain associated with HZ and consequently, ther