A systematic review and meta-analysis of risk factors for postherpetic neuralgia

Age-related changes in the immune system and challenges for the development of age-specific vaccines

BACKGROUND

A better understanding of how the immune system evolves with age and how vaccines work in older people has led to increasing focus on the development of vaccines aimed specifically at older age groups. We discuss strategies used to improve vaccine immunogenicity for older adults, focusing on licensed adjuvants.

FINDINGS

With age-related immune decline (immunosenescence), older adults face increased vulnerability to infections and severe complications. Immunosenescence affects T-cell and B-cell populations and innate immunity, leading to reduced chemotaxis, cytotoxicity, and altered cytokine production. This contributes to inflammaging-low-grade, chronic inflammation linked to aging. However, immune responses vary due to genetics and life-long exposures, making chronological age an imperfect indicator of immune health. Vaccination remains key to prevention, yet immune dysfunction complicates vaccine efficacy. Strategies to enhance responses in older adults include mRNA vaccines, high-antigen content vaccines, intradermal administration, and adjuvants. mRNA COVID-19 vaccines generated strong immune responses in older adults, though lower than in younger groups. High-antigen content influenza vaccines have shown superior efficacy compared to standard vaccination. Adjuvants offer a well-established approach to boosting vaccine responses by enhancing innate immunity.

CONCLUSIONS

Of various strategies used to improve immunogenicity of vaccines for older adults, adjuvants have been the most consistently effective and practical. More recently, mRNA vaccines have also shown great promise.

Default mode network-basal ganglia network connectivity predicts the transition to postherpetic neuralgia

Background

Neuroimaging studies have revealed aberrant network functional connectivity in postherpetic neuralgia (PHN) patients. However, there is a lack of knowledge regarding the relationship between the brain network connectivity during the acute period and disease prognosis.

Objective

The purpose of this study was to detect characteristic network connectivity in the process of herpes zoster (HZ) pain chronification and to identify whether abnormal network connectivity in the acute period can predict the outcome of patients with HZ.

Methods

In this cross-sectional study, 31 patients with PHN, 33 with recuperation from herpes zoster (RHZ), and 28 with acute herpes zoster (AHZ) were recruited and underwent resting-state functional magnetic resonance imaging (fMRI). We investigated the differences in the connectivity of four resting-state networks (RSN) among the three groups. Receiver operating characteristic (ROC) curve analysis was performed to identify whether abnormal network connectivity in the acute period could predict the outcome of patients with HZ.

Results

First, we found within-basal ganglia network (BGN) and default mode network (DMN)-BGN connectivity differences, with PHN patients showing increased DMN-BGN connectivity compared to AHZ and RHZ patients, while RHZ patients showing increased within-BGN connectivity compared to AHZ and PHN patients. Moreover, DMN-BGN connectivity was associated with the ID pain score in patients with AHZ. Finally, the DMN-BGN connectivity of AHZ patients could predict the outcome of HZ patients with sensitivity and specificity of 77.8 % and 63.2 %, respectively.

Conclusions

Our results provide evidence that DMN-BGN connectivity during the acute period confers a risk for the development of chronic pain and can act as a neuroimaging biomarker to predict the outcome of patients with HZ.

The Role of Cytokines in Postherpetic Neuralgia

Nerve injury is a significant cause of postherpetic neuralgia (PHN). It is marked by upregulated expression of cytokines secreted by immune cells such as tumor necrosis factor alpha, interleukin 1 beta (IL-1β), IL-6, IL-18, and IL-10. In neuropathic pain (NP) due to nerve injury, cytokines are important for the induction of neuroinflammation, activation of glial cells, and expression of cation channels. The release of chemokines due to nerve injury promotes immune cell infiltration, recruiting inflammatory cytokines and further amplifying the inflammatory response. The resulting disequilibrium in neuroimmune response and neuroinflammation leads to a reduction of nerve fibers, altered nerve excitability, and neuralgia. PHN is a typical NP and cytokines may induce PHN by promoting central and peripheral sensitization. Currently, treating PHN is challenging and research on the role of cytokine signaling pathways in PHN is lacking. This review summarizes the potential mechanisms of cytokine-mediated PHN and discusses the cytokine signaling pathways associated with the central and peripheral sensitization of PHN. By elucidating the mechanisms of cytokines, the cells and molecules that regulate cytokines, and their signaling systems in PHN, this review reveals important research developments regarding cytokines and their signaling pathways mediating PHN, highlighting new targets of action for the development of analgesic drugs.

T2 high-signal-intensity zone of the spinal cord dorsal horn in patients treated with spinal cord stimulation for herpes zoster-associated pain: a retrospective case-control study

PURPOSE

In patients with herpes zoster-associated pain (ZAP), magnetic resonance imaging (MRI) has revealed T2 high-signal intensity zones (MRI T2 HIZ) in the dorsal horn of the spinal cord, associated with postherpetic neuralgia (PHN). We retrospectively analyzed the relationship between PHN and MRI T2 HIZ in patients with refractory ZAP in the subacute phase who underwent temporary spinal cord stimulation therapy (tSCS).

METHODS

This single-center, case-control study included patients who underwent tSCS for refractory ZAP between 2010 and 2018. MRIs were re-assessed for the presence of T2 HIZ in the dorsal horn of the spinal cord. Patients were divided into T2 HIZ( +) and T2 HIZ(-) groups. Patients with a numerical rating score (NRS) ≥ 3 at the last visit were defined as PHN. The NRS values and the incidence rate of PHN were compared between the two groups.

RESULTS

Of the 67 cases extracted, 38 were included in the analysis: 22 in T2 HIZ( +) group and 16 in T2 HIZ(-) group. No significant differences were observed in background factors between the two groups. However, the T2 HIZ( +) group had a significantly higher NRS at the final visit (T2 HIZ( +):3.8 ± 2.1, T2 HIZ(-):1.4 ± 1.5; P < 0.05) and had significantly more patients with PHN than the T2 HIZ(-) group (T2 HIZ( +) vs. T2 HIZ(-), 15/22 (68%) vs. 3/16 (19%); odds ratio = 8.67; 95% confidence interval, 1.7-63.3).

CONCLUSION

T2HIZ is detected in more than half of refractory ZAP, and pain is more likely to remain after tSCS treatment in the T2HIZ( +) group.

The Use of Tricyclic Antidepressants for Postherpetic Neuralgia - A Case Series

Postherpetic neuralgia (PHN) is one of the most debilitating forms of neuropathic pain that can occur after a herpes zoster infection. PHN can significantly impair patients' quality of life due to persistent neuropathic pain. Current first-line treatments for PHN include anticonvulsants like gabapentin and pregabalin, topical agents such as lidocaine patches, and opioids in severe cases. However, many patients fail to achieve adequate pain control with these medications. Tricyclic antidepressants (TCAs) such as amitriptyline and nortriptyline may be considered as a second-line option, providing relief for patients with refractory pain. TCAs act by modulating neurotransmitters involved in pain pathways, offering analgesia in neuropathic conditions like PHN. This case series reviews four patients with PHN who found significant pain relief with the addition of TCAs after failing multiple other treatments. The patients, aged between 66 and 71, presented with severe PHN and had tried various treatments, including acetaminophen (APAP), nonsteroidal anti-inflammatory drugs (NSAIDs), lidocaine patches, gabapentinoids, and opioids, without achieving adequate pain relief. Each patient was prescribed a TCA, either amitriptyline or nortriptyline, alongside other pain medications. All four patients experienced notable reductions in pain intensity on the Numeric Rating Scale (NRS), resulting in improved daily function and better pain tolerance. Side effects were minimal, with only one patient reporting mild sedation and another reporting transient dry mouth, both of which were manageable. This case series underscores the potential of TCAs in managing PHN, particularly when other medications fail. While the results are promising, further research is needed to confirm the long-term efficacy and safety of TCAs in this patient population.

Exploring the Link Between Diabetes, Herpes Zoster, and Post-Herpetic Neuralgia: Insights From Mendelian Randomization

Background

Diabetes mellitus (DM), herpes zoster (HZ) and its sequelae, post-herpetic neuralgia (PHN), are common in elderly individuals. Previous observational studies have shown that the prevalence of HZ and PHN in conjunction with DM is increasing. Nonetheless, few studies have investigated the causal relationships between DM and the risk of HZ and PHN.

Methods

A two-sample Mendelian randomization (TSMR) analysis was conducted on genome-wide association study (GWAS) data. We obtained four separate datasets for DM: type 1 diabetes (T1D), type 2 diabetes (T2D), mother diabetes mellitus (mother-DM) and father diabetes mellitus (father-DM), and two independent datasets for HZ and anti-varicella-zoster virus IgG (VZV-IgG), a single GWAS for PHN. The inverse variance weighted (IVW), MR‒Egger, weighted median and weighted mode analyses were used to estimate the causality.

Results

Genetically predicted T1D increased the level of VZV-IgG (IVW: OR=1.011, 95% CI 1.006-1.016, P -FDR=8.44×10-6). T2D (IVW: OR=1.313; 95% CI 1.043-1.655, P -FDR=0.041), mother-DM (IVW: OR=7.909; 95% CI 1.232-50.777, P -FDR=0.039), and father-DM (IVW: OR=11.798; 95% CI 2.051-67.874, P -FDR=0.023) increased the risk of PHN. No reverse causality was found between HZ, PHN, and DM.

Conclusion

Our research reveals a causal link between genetically determined T1D and increased VZV-IgG levels. Additionally, genetically predicted T2D and a family history of DM increase the risk of PHN. These discoveries deepen our comprehension of the underlying causes of HZ and PHN.

Effect of herpes zoster vaccine on patients after hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Herpes zoster(HZ), a severe complication following hematopoietic stem cell transplantation (HSCT), is associated with significant morbidity. The effect of herpes zoster vaccine(HZV) for preventing HZ on patients after HSCT is unclear. We conducted a systematic review and meta-analysis investigating the efficacy and safety of HZV in HSCT recipients.

METHODS

The databases Pubmed, Embase, and Cochrane Library were searched to identify relevant studies. Random-effects models were used to calculate risk ratios (RRs) and 95% confidence intervals (CIs) for HZ infection and related events.

RESULTS

A total of 3048 individuals from five studies (four randomized controlled trials and one retrospective cohort study) were included. The overall incidence of HZ in the HZV group and control group was 6.4% and 18.3% respectively, resulting in a pooled RR of 0.36 (95%CI, 0.29-0.45; P < 0.001), indicating no heterogeneity (P = 0.88,I2 = 0). HZV demonstrated a reduction in the risk of PHN (RR, 0.40; 95% CI, 0.15-1.11), although statistical significance was not reached (P = 0.08). Furthermore, through two independent RCTs, HZV showed a decrease in the incidence of HZ-related complications compared to placebo administration. The overall incidence of adverse events in the HZV group and control group was found to be 63.6% and 60.2% respectively, with a pooled RR of 1.02 (95% CI, 0.97-1.06, P = 0.51), indicating no heterogeneity (P = 0.66, I2 = 0).

CONCLUSION

The HZV group demonstrated a significant reduction in the risk of HZ among HSCT recipients, without an increase in adverse events. This highlights the positive impact of HZV on decreasing the incidence of PHN and complications associated with HZ. Furthermore, our findings support the effectiveness and tolerability of HZV as a preventive measure against HZ for HSCT recipients.

Amitriptyline for the prevention of post herpetic neuralgia: study protocol for the ATHENA study

Background

Post herpetic neuralgia (PHN) is the most common complication of herpes zoster, also known as shingles. Amitriptyline has been postulated to prevent PHN. The objective is to determine whether prophylactic low-dose amitriptyline prevents PHN in patients newly diagnosed with shingles.

Methods

This is a multicentre, individually randomized, pragmatic, placebo-controlled superiority trial with health economic analysis and nested qualitative study. Patients with new-onset shingles are screened by treating clinicians in participating general practitioner surgeries. Key eligibility criteria are age ≥50 years, ≤6 days since rash onset and not already taking (and no contraindication to) amitriptyline. Participants are randomized 1:1 to amitriptyline 10 mg or matched placebo tablets (dose escalated as tolerated to a maximum of three tablets daily for 70 days). Resource-use data (including health, social and informal care, personal expenses and usual activities) are collected from electronic medical records and participant questionnaires. A sample of recruitment conversations are audio-recorded and interviews conducted with recruiters and patients, including those who decline to participate or who withdraw from the trial.

Discussion

The primary outcome is the presence of PHN (≥3/10 worst pain on Zoster Brief Pain Inventory) at 90 days after rash onset. Primary health economic analyses will present cost per case of PHN prevented and cost per quality-adjusted life year. Qualitative data will be analysed to optimize trial delivery and to aid interpretation and implementation of the trial findings. This is the largest trial to date to evaluate the clinical/cost-effectiveness and acceptability of prophylactic low-dose amitriptyline for the prevention of PHN.

Protocol registration

EudraCT 2021-001101-78 and ISRCTN14490832.

Herpes zoster after left nephroureterectomy for renal carcinoma: a case report

BACKGROUND

Diabetes and malignant tumors often lead to abnormal immune function, increasing susceptibility to herpes zoster and severe post-herpetic neuralgia. Renal insufficiency following renal cell carcinoma surgery can be compounded by treatment with nephrotoxic antiviral drugs. There have also been case reports of herpes zoster occurring at the surgical site.

CASE PRESENTATION

A 68-year-old man developed herpes zoster at the surgical site and severe neuralgia following left nephroureterectomy for left kidney clear cell carcinoma accompanied by postoperative renal insufficiency. After treatment with brivudine, the herpes was controlled, and neuralgia began to subside by day 3, with crust formation occurring by day 9.

CONCLUSIONS

Postoperative nerve injury and regeneration may influence varicella-zoster virus latency. This case indicates that brivudine is an effective treatment for herpes zoster in patients with chronic renal insufficiency.

Deciphering risk factors for severe postherpetic neuralgia in patients with herpes zoster: an interpretable machine learning approach

INTRODUCTION

Postherpetic neuralgia (PHN) is a common complication of herpes zoster (HZ). This study aimed to use a large real-world electronic medical records database to determine the optimal machine learning model for predicting the progression to severe PHN and to identify the associated risk factors.

METHODS

We analyzed the electronic medical records of 23,326 patients diagnosed with HZ from January 2010 to June 2020. PHN was defined as pain persisting for ≥90 days post-HZ, based on diagnostic and prescription codes. Five machine learning algorithms were compared with select the optimal predictive model and a subsequent risk factor analysis was conducted.

RESULTS

Of the 23,326 patients reviewed, 8,878 met the eligibility criteria for the HZ cohort. Among these, 801 patients (9.0%) progressed to severe PHN. Among the various machine learning approaches, XGBoost-an approach that combines multiple decision trees to improve predictive accuracy-performed the best in predicting outcomes (F1 score, 0.351; accuracy, 0.900; area under the receiver operating characteristic curve, 0.787). Using this model, we revealed eight major risk factors: older age, female sex, history of shingles and cancer, use of immunosuppressants and antidepressants, intensive initial pain, and the neutrophil-to-lymphocyte ratio. When patients were categorized into low-risk and high-risk groups based on the predictive model, PHN was seven times more likely to occur in the high-risk group (p<0.001).

CONCLUSIONS

Leveraging machine learning analysis, this study identifies an optimal model for predicting severe PHN and highlights key associated risk factors. This model will enable the establishment of more proactive treatments for high-risk patients, potentially mitigating the progression to severe PHN.

Successful Thoracic Spinal Cord Stimulator Implantation in a High-Risk Patient With Intractable Intercostal Neuralgia: A Case Report

Intercostal neuralgia can be debilitating and extremely difficult to treat despite multi-modal therapies. The literature describing the role of neuromodulation in patients with intercostal neuralgia is scarce. In this medically challenging case report, we describe a 56-year-old male with a near complete resolution of intractable chronic intercostal neuralgia, secondary to traumatic rib fractures and multiple surgical interventions, with a single lead thoracic spinal cord stimulator (SCS) implant. Neuromodulation therapies should be considered as a viable option for this patient population.

Modelled Public Health Impact of Introducing Adjuvanted Recombinant Zoster Vaccine into the UK National Immunisation Programme

INTRODUCTION

In 2023, recombinant zoster vaccine (RZV) replaced zoster vaccine live (ZVL) vaccine in the UK National Immunisation Programme (NIP) for prevention of herpes zoster (HZ). The vaccination age was reduced from 70 to 65 years, with a subsequent planned reduction to 60 years. This modelling study aimed to evaluate the public health impact (PHI) of RZV vaccination in the 70 years of age (YOA) population and in younger individuals 65 and 60 YOA.

METHODS

PHI was evaluated from a National Health Service perspective, as cases of HZ, post-herpetic neuralgia (PHN), non-PHN complications and deaths, hospitalisations, and general practitioner (GP) visits avoided using a multicohort Markov model. Three scenarios (RZV vs. no vaccination, ZVL vs. no vaccination, and RZV vs. ZVL) were explored for each age group using population estimates from the UK Office for National Statistics, i.e. 70 YOA (n = 649,822), 65 YOA (n = 760,578) and 60 YOA (n = 849,501).

RESULTS

Modelled outcomes in 70 YOA individuals estimated that RZV vaccination would avoid 32,894 cases of HZ and 5915 cases of PHN compared with no vaccination and 26,954 HZ and 3218 PHN cases compared with ZVL. Compared with no vaccination, 2264 fewer hospitalisations and 158,549 fewer GP visits were predicted with RZV vaccination. Hospitalisations were predicted to be reduced by 1996 and GP visits by 130,821 for RZV versus ZVL vaccination. In individuals 65 YOA, it was estimated that RZV vaccination would avoid 50,128 HZ cases, 8623 PHN cases, 222,646 GP visits, and 2671 hospitalisations versus no vaccination. In the 60 YOA group, RZV vaccination was predicted to avoid 57,182 HZ cases, 9327 PHN cases, 234,330 GP visits, and 2547 hospitalisations versus no vaccination.

CONCLUSION

The recent introduction of RZV into the NIP could substantially reduce HZ disease burden and healthcare resource use in the UK. A graphical abstract is available with this article.

The risk of postherpetic neuralgia in COVID-19 vaccination-associated herpes zoster: A retrospective cohort study using TriNetX

BACKGROUND

The administration of the COVID-19 vaccine has been linked to the development of herpes zoster (HZ). However, studies examining the clinical outcomes in COVID-19 vaccination-associated and non-COVID-19 vaccination-associated HZ are lacking.

OBJECTIVE

To investigate the risk of postherpetic neuralgia (PHN) in COVID-19 vaccination associated HZ.

METHODS

A total of 7200 patients with COVID-19 vaccination-associated HZ and 7200 matched controls were enrolled from the US Collaborative Network in the TriNetX database. The main outcome of this study was the development of PHN. Patients were followed-up from 3 months after HZ until PHN diagnoses, withdrawal from the database, or October 8, 2024.

RESULTS

We observed that patients with COVID-19 vaccination-associated HZ had a significantly higher risk of developing PHN as compared to the control group, with hazard ratio of 1.69 (> 3 months), 1.80 (> 6 months), 1.86 (> 1 year), and 1.93 (>2 years), respectively. Additionally, the association remained significant in the stratified analysis, which included sex, age, malignancy status, and initial use of antiviral agents.

CONCLUSION

This study showed that COVID-19 vaccination-associated HZ demonstrated a significantly higher risk of developing PHN.

A Case of Postherpetic Itch Effectively Treated With Pulsed Radiofrequency Therapy

We report a case of a 65-year-old female with postherpetic itch (PHI) over the left chest, who experienced significant relief after pulsed radiofrequency (PRF) therapy. While her initial pain and rash had improved with nerve blocks and medications, she had developed severe itching. PRF therapy significantly reduced the itching, which nearly disappeared. This report suggests that neuropathic pain treatments, like PRF, may also be effective for PHI, a condition that is not fully understood and has limited treatment options but can severely impact the quality of life.

Baseline Participant Characteristics at Enrollment in the Zoster Eye Disease Study

PURPOSE

The Zoster Eye Disease Study (ZEDS) is the first randomized clinical trial to study the efficacy of long-term (1 year) suppressive valacyclovir treatment on herpes zoster ophthalmicus (HZO) outcomes. This article details the baseline characteristics of participants.

METHODS

SETTING

The study was set at 95 participating clinical centers in 33 states, Canada, and New Zealand.

STUDY POPULATION

Immunocompetent adults with a history of a characteristic HZO unilateral rash and documentation of an episode of active dendriform epithelial keratitis, stromal keratitis, endothelial keratitis, or iritis within the preceding year, enrolled in ZEDS from November 2017 to January 2023.

INTERVENTION

Participants were randomized to double-masked oral valacyclovir 1 gm daily versus placebo for 1 year of treatment and followed for 18 months.

RESULTS

Five hundred twenty-seven participants were enrolled across 4 strata according to age at HZO onset (younger or older than 60 years) and duration of HZO at enrollment (less or greater than 6 months), with an even distribution of men and women and a median age of 60 years. More participants with recent (57%, 300/527) than chronic HZO and younger than 60 years at HZO onset (54%, 286/527) were enrolled. Most participants were treated acutely with a recommended antiviral regimen (91%, 480/527) and had not been vaccinated against zoster (79%, 418/527).

CONCLUSIONS

The broad ZEDS study population enhances the likelihood that ZEDS will provide generalizable high-quality evidence regarding the efficacy and safety of suppressive valacyclovir for HZO immunocompetent adults and whether it should become standard of care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03134196.

Investigating the causal effect of various metabolites on postherpetic neuralgia: a Mendelian randomization study

Background

Common side effect of Herpes Zoster, postherpetic neuralgia (PHN), causes persistent pain that seriously affects quality of life. Lack of dependable biomarkers makes the clinical diagnosis and treatment of PHN difficult, so complicating the assessment of therapeutic efficacy. Blood metabolites are becoming more and more well known as significant disease markers. With an aim to find possible biomarkers for diagnosis and treatment, this work investigates the causal link between blood metabolites and PHN using Mendelian randomization.

Methods

This work evaluated causal relationships between PHN and 1,091 plasma metabolites using Mendelian randomization (MR). Complementing MR-Egger and weighted median approaches, the main causality analysis was done using inverse variance weighted (IVW) and Wald ratio (WR) approaches. Robustness was checked using sensitivity analyses including CAUSE, Cochran's Q tests, leave-one-out analysis, MR-PRESSO, and MR-Egger intercept analysis. Reverse MR analysis and linkage disequilibrium score regression (LDSC) was used to assess significant correlations as well. Two-step MR analysis was also used to look at the mediating function of positively correlated metabolites in the causal pathway.

Results

The results of this study indicated a significant association between N-acetyl-aspartyl-glutamate (NAAG) and PHN, with an odds ratio (OR) of 0.83 (95% CI: 0.76-0.91, p = 2.68E-05). Moreover, five potential associated metabolites were identified: Gamma-glutamylthreonine (OR = 1.60, 95% CI: 1.16-2.20, p = 0.004), 3-hydroxyphenylacetoylglutamine (OR = 1.43, 95% CI: 1.00-2.05, p = 0.048), Caprate (10:0) (OR = 1.86, 95% CI: 1.11-3.12, p = 0.018), X-12013 (OR = 1.64, 95% CI: 1.03-2.60, p = 0.035), and X-17328 (OR = 1.50, 95% CI: 1.04-2.18, p = 0.032). Additionally, NAAG likely acts as a complete mediator between FOLH1(CGPII) and postherpetic neuralgia in the causal pathway.

Conclusion

The results of this study indicated a significant association between N-acetyl-aspartyl-glutamate (NAAG) and PHN, with an odds ratio (OR) of 0.83 (95% CI: 0.76-0.91, p = 2.68E-05). Furthermore five possible related metabolites were found: Glutamylthreonine gamma-wise (OR = 1.60, 95% CI: 1.16-2.20, p = 0.004), 3-hydroxyphenylacetoylglutamine (OR = 1.43, 95% CI: 1.00-2.05, p = 0.048), Caprate (10:0) (OR = 1.86, 95% CI: 1.11-3.12, p = 0.018), X-12013 (OR = 1.64, 95% CI: 1.03-2.60, p = 0.035), and X-17328 (OR = 1.50, 95% CI: 1.04-2.18, p = 0.032). Furthermore, in the causal pathway NAAG most certainly serves as a complete mediator between FOLH1(CGPII) and postherpetic neuralgia.

Analysis of Risk Factors and Development and Validation of a Dynamic Nomogram for Postherpetic Neuralgia: A Retrospective Study

Purpose

Postherpetic Neuralgia (PHN), recognized as the most common complication of Herpes Zoster, is experiencing an increasing trend in its occurrence. The goal of this study was to identify the independent risk factors for PHN and create a dynamic nomogram using routine clinical characteristics to predict PHN in patients with herpes zoster, for early identification and prevention of PHN.

Patients and Methods

A total of 2420 patients were retrospectively reviewed and divided into training (n=1696) and validation (n=724) cohort using a 7:3 random allocation. Univariable, LASSO and multivariable logistic regression analysis was performed to identified independent risk factors for PHN. A dynamic nomogram was assessed through the area under the receiver operating characteristic curve (AUC), calibration curves and Hosmer-Lemeshow test. The decision curve analysis (DCA) was used to evaluate its clinical validity.

Results

Multivariable logistic regression identified several independent risk factors for PHN, including age, female, diabetes mellitus, malignant tumors, and connective tissue diseases. The area under the curve was 0.698 (95% CI, 0.666-0.730) for training cohort and 0.713 (95% CI, 0.663-0.763) for the validation cohort. Calibration curve revealed a moderate consistency between actual observation and prediction. Decision curve analysis showed a risk threshold of 16% and demonstrated a clinically effective predictive model.

Conclusion

We have developed a user-friendly dynamic nomogram to predict PHN in patients with herpes zoster, which can assist in early identification and prevention of PHN.

Patient Experience of Herpes Zoster Disease in Argentina: Validation of a Health-Related Quality of Life Conceptual Model

OBJECTIVES

Herpes zoster (HZ) substantially affects patients' health-related quality of life (HRQoL), both in the acute phase and also in those developing postherpetic neuralgia (PHN). Building upon a previous qualitative concept elicitation study in Canada, we adopted a similar approach to further understand the patient experience of HZ/PHN in Argentina and impact on quality of life and qualitatively validate the previously published conceptual model for Argentina.

METHODS

(1) Comprehensive literature review of HZ impact on HRQoL in Latin America. (2) Qualitative concept elicitation interviews with participants aged ≥50 years with acute HZ or PHN. Verbatim interview transcripts underwent thematic and content analysis related to symptoms and impacts.

RESULTS

Studies from the literature (n = 6) identified 5 dimensions of HZ impact on HRQoL: pain management, disease management, family life, work, and emotional impact. A total of 10 participants were interviewed (5 acute HZ and 5 with PHN) with a mean age of 68.5 years (range 50-77 years) and 60% female. All participants reported rash and pain (some reporting a migratory element), fatigue (7 of 10), and itchiness (4 of 10). HRQoL domains most commonly affected were activities of daily living (9 of 10), emotional functioning (8 of 10), physical functioning (8 of 10), and sleep (7 of 10). Emergent themes on disease management included the need for greater public disease awareness/education, participants with PHN seeking alternative/traditional medical therapies.

CONCLUSIONS

This study qualitatively validates the previously reported HRQoL conceptual framework. HZ symptoms, especially acute and chronic pain, substantially impair various aspects of HRQoL, prompting some participants to seek out alternative medical treatments.

Retraction notice to Cost-effectiveness of the Recombinant Zoster Vaccine among People Living with Human Immunodeficiency Virus in Japan: [VHRI Volume 44, November 2024, 101025]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the authors due to an error in the study discovered after the paper was published. In this study, the cost-effectiveness of the recombinant zoster vaccine (RZV) (Shingrix®) for people living with HIV (PLWHIV) aged ≥50 years was analyzed, comparing a 2-dose RZV strategy to no RZV strategy. The initial model indicated that the no RZV strategy was more cost-effective than the 2-dose RZV strategy (Erratum to Table 2). However, an error occurred in the model, where the cost parameter for the 2-dose RZV strategy was mistakenly applied as if PLWHIV individuals received the 2-dose vaccine in every cycle, significantly inflating the cost of this strategy. Upon correcting the model to reflect that the 2-dose RZV is administered only at cycle 0, the revised results indicate that the 2-dose RZV strategy is dominant over the no RZV strategy (Erratum to Table 2). Given that this error leads to a completely reversed conclusion, this paper has been retracted.

Effect of Preoperative Level of Glycemic Control with Pulsed Radiofrequency on the Incidence of Postherpetic Neuralgia in Patients with Herpes Zoster Combined with Type 2 Diabetes Mellitus: A Cohort Study

Purpose

To investigate the correlation between the level of glycosylated hemoglobin (HbA1c) and postherpetic neuralgia (PHN).

Patients and Methods

This cohort study included 100 patients with herpes zoster (HZ) undergoing treatment with pulsed radiofrequency (PRF). Patients with comorbid type 2 diabetes mellitus (T2DM) were divided into three groups based on their glycemic control levels: good [HbA1c < 7% (53.01 mmol/mol), group D1], fair [7% (53.01 mmol/mol) ≤ HbA1c < 9% (74.86 mmol/mol), group D2], and poor [9% (74.86 mmol/mol) ≤ HbA1c, group D3]. The control group (group N) consisted of patients without T2DM. The main outcome measured was the occurrence of PHN in the four groups.

Results

A total of 90 patients were included in the cohort. The occurrence of PHN was found to be higher in groups D2 and D3 when compared to group N (N vs D2, P = 0.007; N vs D3, P < 0.001). Furthermore, the occurrence of PHN was higher in groups D2 and D3 in comparison to group D1 (D1 vs D2, P = 0.022; D1 vs D3, P < 0.001), with the incidence of PHN in group D3 being greater than in group D2 (P < 0.001).

Conclusion

Preoperative HbA1c predicts the incidence of PHN after PRF in T2DM patients.

Validity of Plasma Neuropeptide Y in Combination with Clinical Factors in Predicting Neuralgia Following Herpes Zoster

Background

Numerous lines of evidence suggest that neuropeptide Y (NPY) is critically involved in the modulation of neuropathic pain. Postherpetic neuralgia (PHN) is characterized by prolonged duration, severe pain, and significant treatment resistance, substantially impairing patients' quality of life. This study aims to evaluate the potential of plasma NPY levels in patients with PHN as a predictive biomarker for the development of this condition.

Methods

Between February 2022 and December 2023, 182 patients with herpes zoster (HZ) were recruited. Thirty-eight volunteers with no history of HZ were also recruited as controls. Clinical factors, NPY, brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) were assessed within 3 days of healing. Logistic regression analysis was used to predict the development of PHN.

Results

NPY levels were lower and BDNF and NGF were higher in HZ patients than those in controls. Only NPY levels were lower in patients with PHN (n = 59) compared with those without PHN (n = 123). Age, acute pain severity, and rash area were independent predictors of PHN, as were NPY levels. The area under the curve (AUC) to predict the development of PHN based on the combination of NPY levels and clinical factors was 0.873 (95% CI: 0.805 to 0.940), and the AUC was 0.804 based on only clinical factors (AUC: 0.804, 95% CI: 0.728 to 0.881).

Conclusion

Low plasma NPY levels are a predictor of developing PHN in patients with HZ. Combining clinical predictors with NPY levels may improve predictive accuracy.

8. Herpes zoster and post herpetic neuralgia

INTRODUCTION

Patients suffering from postherpetic neuralgia (PHN) report unilateral chronic pain in one or more dermatomes after an acute herpes zoster (HZ) infection. The incidence of acute HZ ranges between three and five patients per 1000 person-years. In one out of four patients, acute HZ-related pain will transition into PHN. PHN can be very disabling for patients and reduce quality of life. Additionally, the treatment of PHN is characterized by high failure rates. The aim of this review is to give an update on the previous practical guideline published in 2011 and revised in 2015 (published in 2019) and to provide an overview of current interventional treatment options for HZ infection and PHN.

METHODS

The literature on the diagnosis and treatment of HZ and PHN was systematically reviewed and summarized.

RESULTS

The most important treatment for acute HZ-related pain is antiviral therapy within 72 h of symptom onset. Additional symptomatic treatment options are analgesic drugs according to the WHO pain ladder, tricyclic antidepressants (eg, nortriptyline), and antiepileptic drugs (eg, gabapentin). If pain is not sufficiently reduced, interventional treatment such as an epidural injection with local anesthetics and corticosteroids or pulsed radiofrequency of the dorsal root ganglion (DRG) are options. Treatment for PHN is preferably transdermal capsaicin, lidocaine, or oral drugs such as antidepressants or antiepileptics.

CONCLUSIONS

Treatment of acute HZ-related pain especially PHN is challenging. Besides the conventional treatment for PHN, interventional management is considered a new treatment option. PRF of DRG seems to be the most promising interventional management.

Peripheral Neuropathic Pain

OBJECTIVE

This article synthesizes current knowledge on neuropathic pain, with a brief review of mechanisms, diagnostic approaches, and treatment strategies to help neurologists provide effective and individualized care for patients with this complex condition.

LATEST DEVELOPMENTS

The most promising developments in peripheral neuropathic pain are related to the molecular biology of the peripheral nervous system. Systematic molecular and genetic analyses of peripheral nerve terminals and dorsal root ganglia have advanced our understanding of the genetics of function and disease of peripheral nerves, as well as their physiology and clinical manifestations.

ESSENTIAL POINTS

Peripheral neuropathic pain, similar to central neuropathic pain, is primarily influenced by the biology and pathophysiology of the underlying structures, peripheral sensory nerves, and their central pathways. The clinical course is widely variable in sensory symptoms and intensities, natural history, and response to treatments.

Identifying and Evaluating Biological Markers of Postherpetic Neuralgia: A Comprehensive Review

Postherpetic neuralgia (PHN) manifests as persistent chronic pain that emerges after a herpes zoster outbreak and greatly diminishes quality of life. Unfortunately, its treatment efficacy has remained elusive, with many therapeutic efforts yielding less than satisfactory results. The research to discern risk factors predicting the onset, trajectory, and prognosis of PHN has been extensive. However, these risk factors often present as nonspecific and diverse, indicating the need for more reliable, measurable, and objective detection methods. The exploration of potential biological markers, including hematological indices, pathological insights, and supportive tests, is increasing. This review highlights potential biomarkers that are instrumental for the diagnosis, management, and prognosis of PHN while also delving deeper into its genesis. Drawing from prior research, aspects such as immune responsiveness, neuronal injury, genetic makeup, cellular metabolism, and pain signal modulation have emerged as prospective biomarkers. The immune spectrum spans various cell subtypes, with an emphasis on T cells, interferons, interleukins, and other related cytokines. Studies on nerve injury are directed toward pain-related proteins and the density and health of epidermal nerve fibers. On the genetic and metabolic fronts, the focus lies in the detection of predisposition genes, atypical protein manifestations, and energy-processing dynamics, with a keen interest in vitamin metabolism. Tools such as functional magnetic resonance imaging, electromyography, and infrared imaging have come to the forefront in the pain signaling domain. This review compiles the evidence, potential clinical implications, and challenges associated with these promising biomarkers, paving the way for innovative strategies for predicting, diagnosing, and addressing PHN.

Association of the incidence of postherpetic neuralgia with early treatment intervention of herpes zoster and patient baseline characteristics: A systematic review and meta-analysis of cohort studies

OBJECTIVES

To conduct a meta-analysis of the association between postherpetic neuralgia (PHN), baseline characteristics of patients with herpes zoster (HZ), and early interventions.

METHODS

Literature searches were conducted in seven databases, in June 2021 and updated in June 2022. Two investigators independently conducted literature screening and data extraction, and the studies were evaluated according to the Newcastle-Ottawa scale.

RESULTS

A total of 53 cohort studies were included. The meta-analyses identified skin lesions, timing of initial treatment (≥3 days), and comorbidities as potential risk factors for PHN. In contrast, female sex (odds ratio [OR] = 1.13, 95% confidence interval [CI]: 0.99-1.29), cervical herpes (OR = 0.80, 95% CI: 0.21-2.99), lumbar herpes (OR = 1.29, 95% CI: 0.61-2.74), and immunosuppressive therapy (OR = 1.96, 95% CI: 0.22-17.12), were not significantly associated with PHN. In addition, glucocorticoid use (OR = 0.61, 95% CI: 0.22-1.70) may be a protective factor for the development of PHN; however, the difference was not statistically significant.

CONCLUSION

A series of baseline characteristics were identified among populations at high risk of developing PHN from HZ. Additionally, the timing of initial treatment is associated with PHN occurrence. The preventive effect of glucocorticoids warrants further validation.

Efficacy of Gasserian Ganglion High-Voltage, Long-Duration Pulsed Radiofrequency Combined With Block on Acute/Subacute Zoster-Related Trigeminal Neuralgia

Background: Trigeminal postherpetic neuralgia (TPHN) is a severe chronic pain that can lead to various socioeconomic consequences. Therefore, it is necessary to explore optimal treatment options for acute/subacute herpes zoster (HZ)-related trigeminal neuralgia and prevent the further development of TPHN. High-voltage, long-duration pulsed radiofrequency (HL-PRF) of the Gasserian ganglion is a new surgical intervention used to treat PHN. A ganglion block has been reported to possess anti-inflammatory effects and potential analgesic benefits. Methods: We included 83 patients with HZ-related acute/subacute trigeminal neuralgia admitted from January 1, 2021, to June 1, 2023, and received Gasserian ganglion HL-PRF combined with block. A 6-month follow-up was conducted, including Numerical Rating Scale (NRS) scores, Pittsburgh Sleep Quality Index (PSQI), the incidence of TPHN, the dosage of anticonvulsants and analgesics, efficacy, and adverse events. Results: All patients showed a significant decrease in postoperative NRS scores (p < 0.05). The NRS scores of the acute HZ group were consistently lower than those of the subacute HZ group at different time points (p < 0.01). The overall incidence of TPHN from the onset of HZ to 12 weeks is 21.68%. The incidence of TPHN in the acute phase group was 12.77%, significantly lower than the 33.33% in the subacute phase group (p=0.024). The effective rate was 74.7% in all patients, at 3 months after the treatment. The effective rate was 82.98% in the acute phase group and 63.89% in the subacute phase group, showing a statistically significant difference (p=0.047). The PSQI score of the acute group was consistently lower than that of the subacute group (p < 0.01). The dosage of analgesics and anticonvulsants used in the acute HZ group was lower than that in the subacute group (p < 0.01). All patients did not experience serious adverse reactions. Conclusions: Gasserian ganglion HL-PRF combined with block can be an effective and safe technique to relieve the pain of acute/subacute zoster-related trigeminal neuralgia and prevent the incidence of TPHN.

Natural Language Processing Versus Diagnosis Code-Based Methods for Postherpetic Neuralgia Identification: Algorithm Development and Validation

Background

Diagnosis codes and prescription data are used in algorithms to identify postherpetic neuralgia (PHN), a debilitating complication of herpes zoster (HZ). Because of the questionable accuracy of codes and prescription data, manual chart review is sometimes used to identify PHN in electronic health records (EHRs), which can be costly and time-consuming.

Objective

This study aims to develop and validate a natural language processing (NLP) algorithm for automatically identifying PHN from unstructured EHR data and to compare its performance with that of code-based methods.

Methods

This retrospective study used EHR data from Kaiser Permanente Southern California, a large integrated health care system that serves over 4.8 million members. The source population included members aged ≥50 years who received an incident HZ diagnosis and accompanying antiviral prescription between 2018 and 2020 and had ≥1 encounter within 90-180 days of the incident HZ diagnosis. The study team manually reviewed the EHR and identified PHN cases. For NLP development and validation, 500 and 800 random samples from the source population were selected, respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), F-score, and Matthews correlation coefficient (MCC) of NLP and the code-based methods were evaluated using chart-reviewed results as the reference standard.

Results

The NLP algorithm identified PHN cases with a 90.9% sensitivity, 98.5% specificity, 82% PPV, and 99.3% NPV. The composite scores of the NLP algorithm were 0.89 (F-score) and 0.85 (MCC). The prevalences of PHN in the validation data were 6.9% (reference standard), 7.6% (NLP), and 5.4%-13.1% (code-based). The code-based methods achieved a 52.7%-61.8% sensitivity, 89.8%-98.4% specificity, 27.6%-72.1% PPV, and 96.3%-97.1% NPV. The F-scores and MCCs ranged between 0.45 and 0.59 and between 0.32 and 0.61, respectively.

Conclusions

The automated NLP-based approach identified PHN cases from the EHR with good accuracy. This method could be useful in population-based PHN research.

Neuromodulation for postherpetic neuralgia: Preliminary experience in a single center

BACKGROUND

Postherpetic neuralgia (PHN) after herpes zoster is a debilitating complication that severely affects the quality of life of patients. Neuromodulation such as spinal cord stimulation (SCS) and trigeminal semilunar ganglion stimulation (TSGS) have become effective methods for treating postherpetic neuralgia.

METHODS

A retrospective analysis of clinical data from 30 patients with postherpetic neuralgia who underwent SCS or TSGS treatment from January 2022 to January 2024. Patients received conventional treatment before neuromodulation. Clinical data including patient age, gender, pain characteristics, treatment outcomes were collected. The efficacy was evaluated using the Visual Analog Scale (VAS) and the Modified Global Impression of Change scale. Optimal stimulation parameters were also analyzed.

RESULTS

The results showed that postoperative pain was significantly reduced in both SCS and TSGS groups, with a higher satisfaction rate in the SCS group (89 % vs. 77 %). The optimal stimulation parameters for the two treatments were also different. Compared to SCS, TSGS required a higher frequency but lower pulse width and voltage.

CONCLUSION

This study suggests that neuromodulation may be an effective treatment for PHN, but the subtle differences between SCS and TSGS support a more personalized treatment approach.

Efficacy of Botulinum Type A Injection for the Treatment of Postherpetic Neuralgia and Pruritus Persisting for More Than Four Years-A Case Report

Background: Postherpetic neuralgia (PHN) and postherpetic pruritus (PHP) are common complications of shingles that affect patients' quality of life. PHN and PHP can be managed using various medications and interventional procedures; however, complications persisting for at least six months may hamper recovery. Subcutaneous injections of botulinum toxin type A (BTX-A) can control persistent PHN and PHP. Case presentation: A 71-year-old man presented at our hospital with itching and pain. He had been diagnosed with shingles in the ophthalmic branch of the trigeminal nerve one year previously. As the pain and itching persisted despite medication, a supraorbital nerve block, Gasserian ganglion block, epidural nerve block, and radiofrequency thermocoagulation were performed. A subcutaneous injection of BTX-A was administered into the ophthalmic area of the trigeminal nerve three years after the initial presentation. A decrease of >80% in pain and itching was reported after the injection; however, the left eyelid drooped and the eyeball shifted downward and outward immediately after the injection. No deterioration in vision or pupil dilation was observed, and almost complete resolution of these symptoms occurred spontaneously three months after the injection. Pain and itching continued to improve without further side-effects until six months after the injection. Conclusions: The subcutaneous injection of BTX-A may be an alternative treatment option for chronic and refractory neurological diseases such as PHN and PHP, which persist for four years and are resistant to conventional treatments. Nevertheless, care must be taken to minimize the risk of ptosis.

Peripheral and central pathogenesis of postherpetic neuralgia

BACKGROUND

Postherpetic neuralgia (PHN) is a classic chronic condition with multiple signs of peripheral and central neuropathy. Unfortunately, the pathogenesis of PHN is not well defined, limiting clinical treatment and disease management.

OBJECTIVE

To describe the peripheral and central pathological axes of PHN, including peripheral nerve injury, inflammation induction, central nervous system sensitization, and brain functional and structural network activity.

METHODS

A bibliographic survey was carried out, selecting relevant articles that evaluated the characterization of the pathogenesis of PHN, including peripheral and central pathological axes.

RESULTS

Currently, due to the complexity of the pathophysiological mechanisms of PHN and the incomplete understanding of the exact mechanism of neuralgia.

CONCLUSION

It is essential to conduct in-depth research to clarify the origins of PHN pathogenesis and explore effective and comprehensive therapies for PHN.

A Prognostic Model Incorporating Relevant Peripheral Blood Inflammation Indicator to Predict Postherpetic Neuralgia in Patients with Acute Herpes Zoster

Objective

To determine the risk of postherpetic neuralgia (PHN) in patients with acute herpes zoster (HZ), this study developed and validated a novel clinical prediction model by incorporating a relevant peripheral blood inflammation indicator.

Methods

Between January 2019 and June 2023, 209 patients with acute HZ were categorized into the PHN group (n = 62) and the non-PHN group (n = 147). Univariate and multivariate logistic regression analyses were conducted to identify risk factors serving as independent predictors of PHN development. Subsequently, a nomogram prediction model was established, and the discriminative ability and calibration were evaluated using the receiver operating characteristic curve, calibration plots, and decision curve analysis (DCA). The nomogram model was internally verified through the bootstrap test method.

Results

According to univariate logistic regression analyses, five variables, namely age, hypertension, acute phase Numeric Rating Scale (NRS-11) score, platelet-to-lymphocyte ratio (PLR), and systemic immune inflammation index, were significantly associated with PHN development. Multifactorial analysis further unveiled that age (odds ratio (OR) [95% confidence interval (CI)]: 2.309 [1.163-4.660]), acute phase NRS-11 score (OR [95% CI]: 2.837 [1.294-6.275]), and PLR (OR [95% CI]: 1.015 [1.010-1.022]) were independent risk factors for PHN. These three predictors were integrated to establish the prediction model and construct the nomogram. The area under the receiver operating characteristic curve (AUC) for predicting the PHN risk was 0.787, and the AUC of internal validation determined using the bootstrap method was 0.776. The DCA and calibration curve also indicated that the predictive performance of the nomogram model was commendable.

Conclusion

In this study, a risk prediction model was developed and validated to accurately forecast the probability of PHN after HZ, thereby demonstrating favorable discrimination, calibration, and clinical applicability.

Parabolic Changes in Pain Scores Among Partial Herpes Zoster Patients: A Retrospective Study

Background

Herpes zoster (HZ) typically manifests in the acute phase with distinct blisters and severe neuropathic pain. Remarkably, a subset of patients initially presents with only a mild skin rash and moderate pain that gradually intensifies, following a parabolic pattern. Despite being frequently observed in clinical settings, the underlying causes of this trajectory and its potential connection with post-herpetic neuralgia (PHN) remain unclear.

Methods

To investigate this phenomenon in-depth, we conducted a meticulous retrospective study involving 529 eligible HZ patients. All these patients sought medical care at the Third Central Hospital of Tianjin, China, between January 2020 and December 2023.

Results

The research identified that 14.6% of the sample (77 patients) experienced pain scores aligning with a parabolic curve. This trend was significantly more prevalent in patients aged 60 and above, accounting for 90.9% of this group, and demonstrated a positive correlation with age. Moreover, 87.0% of these patients had pre-existing medical conditions, highlighting the potential role of comorbidities in influencing the pain trajectory. A concerning 45.5% of patients sought medical attention more than seven days after the onset of symptoms, a delay that could exacerbate neurological damage. Notably, among those following a parabolic pain pattern, 66.2% eventually developed PHN, a considerably higher rate compared to the broader patient population.

Conclusion

We emphasize that healthcare practitioners meticulously assess patients who initially report lower pain scores for high-risk factors potentially leading to parabolic pain increases, including being over 60 years old, having comorbid conditions, and delaying medical consultation beyond seven days from symptom onset. Early implementation of supplementary pain management therapies may mitigate the risk of PHN development and enhance the quality of life for patients. This study furnishes clinicians with a deeper understanding of the variations in HZ-related pain trajectories, promising to improve treatment approaches and prognoses for HZ patients while paving the way for enriched clinical practice in the future.

Genetics of causal relationships between circulating inflammatory proteins and postherpetic neuralgia: a bidirectional Mendelian randomization study

Objective

According to data from several observational studies, there is a strong association between circulating inflammatory cytokines and postherpetic neuralgia (PHN), but it is not clear whether this association is causal or confounding; therefore, the main aim of the present study was to analyze whether circulating inflammatory proteins have a bidirectional relationship with PHN at the genetic inheritance level using a Mendelian randomization (MR) study.

Methods

The Genome-Wide Association Study (GWAS) database was used for our analysis. We gathered data on inflammation-related genetic variation from three GWASs of human cytokines. These proteins included 91 circulating inflammatory proteins, tumor necrosis factor-alpha (TNF-α), macrophage inflammatory protein 1b (MIP-1b), and CXC chemokine 13 (CXCL13). The PHN dataset was obtained from the FinnGen biobank analysis round 5, and consisted of 1,413 cases and 275,212 controls. We conducted a two-sample bidirectional MR study using the TwoSampleMR and MRPRESSO R packages (version R.4.3.1). Our main analytical method was inverse variance weighting (IVW), and we performed sensitivity analyses to assess heterogeneity and pleiotropy, as well as the potential influence of individual SNPs, to validate our findings.

Results

According to our forward analysis, five circulating inflammatory proteins were causally associated with the development of PHN: interleukin (IL)-18 was positively associated with PHN, and IL-13, fibroblast growth factor 19 (FGF-19), MIP-1b, and stem cell growth factor (SCF) showed reverse causality with PHN. Conversely, we found that PHN was closely associated with 12 inflammatory cytokines, but no significant correlation was found among the other inflammatory factors. Among them, only IL-18 had a bidirectional causal relationship with PHN.

Conclusion

Our research advances the current understanding of the role of certain inflammatory biomarker pathways in the development of PHN. Additional verification is required to evaluate the viability of these proteins as targeted inflammatory factors for PHN-based treatments.

Incidence of herpes zoster in patients with inflammatory bowel disease

BACKGROUND

Herpes zoster (HZ) is a prevalent disease caused by the reactivation of the varicella-zoster virus (VZV) and associated with chronic morbidity, particularly with post-herpetic neuralgia (PHN). Inflammatory bowel disease (IBD) has been associated with an increased risk of HZ, mainly when immunosuppressive treatment (IMT) is used. However, studies assessing the risk of HZ in IBD are scarce.

AIMS

To evaluate the incidence rate and risk factors of HZ in IBD.

METHODS

Retrospective study in IBD patients with a positive VVZ serology from two referral hospitals from the area of Barcelona. Diagnosis of HZ and its clinical features were recorded.

RESULTS

A total of 398 IBD patients with a positive IgG-VVZ serology were identified. Fifty-eight percent of the patients received IMT (46.5% immunosuppressants monotherapy, 20.6% biologics monotherapy and, 32.7% combination therapy). After a median follow-up of 71 months (IQR 41.5-138.0), 17 (4.3%) patients developed HZ (cumulative incidence of 5.2 per 1000 person-year), 12 of them (70.6%) while receiving IMT. Median age at HZ episode was 38 years (IQR 27.5-52.5). Two (11%) developed PHN. Biological therapy was the only risk factor for developing HZ (OR 3.8 IC 95% 1.3-11.5; p=0.018).

CONCLUSIONS

HZ is quite prevalent in IBD, occurring at early ages and particularly among patients using IMT. NPH appears to occur in a notable proportion of cases.

Herpes zoster in Belgium: a new solution to an old problem

Herpes zoster (HZ) is caused by reactivation of the varicella-zoster virus. The life-time risk of developing HZ is ~ 30%. Management of HZ can be challenging due to limited efficacy of oral antivirals on pain control, and neuropathic pain that may require aggressive management. Post-herpetic neuralgia (PHN) can cause substantial pain and occurs in up to one-quarter of patients with HZ. Up to 48,000 HZ cases are estimated to occur annually in Belgium, estimated to cost almost 7 million euros in treatment. The recombinant zoster vaccine (RZV, Shingrix, GSK) was approved in Europe in 2017. In 2022, the Belgian Superior Health Council recommended vaccination with RZV for immunocompetent adults aged ≥ 60 years, and immunocompromised patients aged ≥ 16 years, including those receiving immunosuppressive therapy, in particular Janus kinase inhibitors. RZV showed high age-independent efficacy in preventing HZ infection and in clinical trials that has since been confirmed in real-world effectiveness studies. In clinical trials, protection was sustained for at least 10 years after vaccination. As of 1 November 2023, RZV is reimbursed for three immunocompromised patient groups aged ≥ 18 years: malignancy treated in the past 5 years, HIV infection, and organ or haematological stem cell transplantation or are a transplant candidate. HZ is vaccine-preventable and RZV provides a highly effective tool for HZ prevention. While reimbursement for some at-risk groups is welcomed, reimbursement currently falls well short of Superior Health Council recommendations. Adult immunisation strategies should be promoted to achieve high vaccination coverage against HZ, contributing to healthy aging in Belgium.

Efficacy and safety of therapies related to acupuncture for acute herpes zoster: A PRISMA systematic review and network meta-analysis

BACKGROUND

Herpes zoster (HZ) is mainly characterized by intense pain and severe skin lesions, particularly during the acute phase, which seriously affects the patient's quality of life. Acupuncture is a widely used and effective treatment for HZ. However, there are many types of acupuncture, which have different curative efficacy. This study employed a network meta-analysis (NMA) to assess and rank the clinical efficacy of different acupuncture therapies.

METHODS

The database of Cochrane Library, Web of Science, PubMed, MEDLINE, Embase, China National Knowledge Infrastructure (CNKI), Chinese BioMedical Database, VIP Database, and Wanfang Database were searched from inception to December 31, 2022 to identify eligible randomized controlled trials (RCTs) of acupuncture related therapies in the treatment of acute HZ. The outcome indicators measured were visual analogue scale (VAS), date of cessation of herpes increase (DCHI), effective rate (ER), postherpetic neuralgia (PHN), and adverse events (AEs). Bayesian network meta-analyses were performed using the GeMTC package (version 1.0-1) and R software (version 4.2.3).

RESULTS

A total of 59 RCTs with 3930 patients were included. The results of this NMA were as follows: compared with pharmacotherapy, electroacupuncture (EA) + pricking and cupping (PC) shown the best efficacy to improve VAS score and reduce DCHI. In terms of ER, EA + fire needle (FN) had the highest results of probability ranking. PC was more effective in reducing the incidence of PHN. Furthermore, this study shown that the incidence of AEs associated with acupuncture-related therapies was acceptable.

CONCLUSIONS

This study indicated that therapies related to acupuncture were both effective and safe in treating acute HZ, and could significantly reduce patients' symptoms such as pain and skin lesions with fewer adverse events. Clinically, the selection of the appropriate therapy should be based on practical considerations. However, due to the limitations of this study, more high-quality trials are required to evaluate the efficacy and safety of acupuncture-related therapy for the treatment of acute HZ.

Systematic Literature Review on the Incidence of Herpes Zoster in Populations at Increased Risk of Disease in the EU/EEA, Switzerland, and the UK

INTRODUCTION

Older adults and patients with underlying conditions such as immunocompromised (IC) populations (e.g., due to medical conditions or immunosuppressive medication) are at increased risk for herpes zoster (HZ). The first HZ recombinant vaccine for IC patients was approved in 2020. Limited evidence exists to inform decision-makers on HZ incidence in high-risk patients in Europe. This systematic literature review (SLR) assessed HZ incidence across 14 high-risk populations in the European Union/European Economic Area, Switzerland, and the United Kingdom.

METHODS

An SLR (Embase, Medline, 2002-2022, observational studies) was performed to identify HZ incidence (i.e., primary outcomes: rate or cumulative; secondary: relative incidence) in type 1 and 2 diabetes mellitus (DM); chronic obstructive pulmonary disease and asthma; depression; rheumatic disorders (RD); multiple sclerosis (MS); inflammatory bowel diseases (IBD); psoriasis; lupus; human immunodeficiency virus (HIV); solid organ transplantation (SOT); solid organ malignancy (SOM); hematologic malignancy (HM); and stem cell transplantation (SCT).

RESULTS

Of 776 unique records screened, 59 studies were included (24 reported incidence rate per 1000 person-years; two, cumulative incidence per 1000 persons; and 33, relative incidence). The highest incidence rates were reported for SOT (12.1-78.8) and SCT (37.2-56.1); HM (2.9-32.0); RD (0.41-21.5); lupus (11.0-16.5); IC mixed population (11.3-15.5); HIV/AIDS (11.8-13.0); chronic respiratory diseases (4.7-11.4); SOM (8.8-11.0); IBD (7.0-10.8); DM (4.3-9.4); depression (7.2-7.6); MS (5.7-6.3); and psoriasis (5.3-6.1). In many high-risk populations, HZ incidence was higher for older age groups, women, and some treatments.

CONCLUSIONS

The HZ incidence rate in Europe increased with age and varied across high-risk populations, with high rates for solid organ and stem cell transplants, cancer, and rheumatoid arthritis. Most studies were retrospective with methodological differences affecting generalizability and comparability. Future studies should stratify data by IC population, age, sex, severity, medication, and study timeframe.

Combined Therapy of Paravertebral Nerve Pulsed Radiofrequency and Subcutaneous Block for Acute/Subacute Herpetic Neuralgia: A Retrospective Study

OBJECTIVES

This retrospective study aimed to investigate the effectiveness and safety of early combined therapy with CT-guided paravertebral nerve (PVN), pulsed radiofrequency (PRF), and subcutaneous block on acute/subacute herpes zoster (HZ).

METHODS

A total of 98 medical records were analyzed. All patients underwent CT-guided PRF on PVN immediately followed by a single subcutaneous block with lidocaine and dexamethasone in acute/subacute phase. The therapy efficacy was evaluated by pain numeric rating scale (NRS) and effective rate, which was defined as a percent of cases with a reduction in pain NRS>50% at day 1, week 2, 4, 12, and 24 after the procedure. The incidences of medication reduction and postherpetic neuralgia (PHN) were also retrieved. Further comparison was conducted between acute group (disease duration<30 days from HZ onset) and subacute group (30 day

RESULTS

Early combined therapy indicated an immediate and sustained improvement in pain NRS as compared with before treatment ( P <0.0001), with effective rates of 74%, 79%, 80%, 76%, and 79% at day 1, week 2, 4, 12, and 24 after procedure, respectively. At the end of follow-up, the proportion of patients with a reduction of >50% in prior medications amounted to 83% and the incidence of clinically meaningful PHN decreased to 23%. The clinical efficacy was more profound in acute group than in subacute group at every time points ( P <0.05). No severe complications occurred.

DISCUSSION

Our data revealed surprising levels of pain relief by combination therapies of PRF and subcutaneous block targeting different sites of pain pathway, thus suggesting a valuable treatment option for acute/subacute herpetic neuralgia.

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Key Words Collapse

MESH Headings

• Humans
• Retrospective Studies
• Pulsed Radiofrequency Treatment/methods
• Neuralgia/complications
• Neuralgia, Postherpetic/therapy
• Herpes Zoster/complications
• Herpes Zoster/therapy

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Grants Collapse

Affiliation(s)

Wei Zhang Departments of Day Surgery
Bin Yu Departments of Day Surgery
Zipu Jia Departments of Day Surgery
Chunmei Zhao Day Surgery and Pain Management, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China
Fang Luo Day Surgery and Pain Management, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China

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Trigeminal Postherpetic Neuralgia: From Pathophysiology to Treatment

PURPOSE OF REVIEW

Trigeminal postherpetic neuralgia (TG-PHN) is a neuropathic pain condition complicating herpes zoster (HZ) attributed to the trigeminal nerve. It poses significant challenges due to its persistent and debilitating nature. This review explores the clinical characteristics of TG-PHN, analyzes its pathophysiological underpinnings, and addresses existent and potential therapies.

RECENT FINDINGS

TG-PHN is one of the most common and complex PHN locations. It has distinguishing clinical and pathophysiological characteristics, starting with viral triggered injuries to the trigeminal ganglion (TG) and peripheral tissue and involving the ascending and descending brain modulation pathways. Current therapies include vaccines, oral and topical medications, and interventional approaches, like nerve blocks and neurostimulation. This review covers TG-PHN's clinical and physiological components, treatment options, and potential future targets for improved management. By exploring the complexities of this condition, we aim to contribute to developing more effective and targeted therapies for patients suffering from trigeminal PHN.

Efficacy and safety of intravenous fosphenytoin for patients with acute herpes zoster-associated pain: A placebo-controlled randomized trial

Acute zoster-associated pain develops in most patients with herpes zoster. Nonopioid analgesics are usually used to treat acute zoster-associated pain but are frequently ineffective. We administered intravenous fosphenytoin, the prodrug of phenytoin, to patients with acute zoster-associated pain to examine its analgesic efficacy and safety. At 13 medical institutions in Japan, we conducted a phase II, double-blind, placebo-controlled, randomized trial of intravenous fosphenytoin in Japanese inpatients with acute zoster-associated pain for whom nonopioid analgesics had shown an insufficient analgesic effect. The patients were randomly assigned (1:1:1) to receive a single intravenous dose of fosphenytoin at 18 mg/kg (high dose), a single intravenous dose of fosphenytoin at 12 mg/kg (low dose), or placebo. The primary endpoint was the mean change per hour (slope) in the numerical rating scale score from the baseline score until 120 min after dosing. Seventeen patients were randomly assigned to the low-dose fosphenytoin group (n = 6, median age 62.5 years, range 39-75 years), high-dose fosphenytoin group (n = 5, median age 69.0 years, range 22-75 years), and placebo group (n = 5, median age 52.0 years, range 38-72 years). One patient was excluded because of investigational drug dilution failure. This study was discontinued because of the influences of coronavirus disease 2019. The slope was significantly lower in the high- and low-dose fosphenytoin groups than in the placebo group (P < 0.001 and P = 0.016, respectively). Responsiveness to intravenous fosphenytoin (≥2-point reduction in the numerical rating scale score from baseline to 120 min after dosing) was inferred at plasma total phenytoin concentrations of 10-15 μg/mL. Treatment-emergent adverse events caused no safety concerns in the clinical setting and intravenous fosphenytoin was well tolerated. Intravenous fosphenytoin appears to be an effective and promising alternative treatment for acute zoster-associated pain. Trial Registration: ClinicalTrials.gov NCT04139330.

Effect of CT-Guided Repeated Pulsed Radiofrequency on Controlling Acute/Subacute Zoster-Associated Pain: A Retrospective Cohort Study

INTRODUCTION

Zoster-associated pain (ZAP) treatment and management is still inadequate. Repeated intervention protocol is often applied to manage ZAP. This study aimed to retrospectively investigate the effect of repeated applications of pulsed radiofrequency therapy on controlling acute/subacute ZAP.

METHODS

From March 2019 to December 2021, 150 patients with acute/subacute ZAP who underwent repeated application of pulsed radiofrequency treatment (R-PRF) and pulsed radiofrequency combined paravertebral block interventions (PRF + PVB) in the Pain Department of the affiliated Hospital of Jiaxing University were enrolled. Patients were grouped by intervention protocol and received at least 12 months of follow-up assessments using the Numerical Rating Scale score (NRSs), Pittsburg Sleep Quality Index (PSQI), Simple McGill Pain Questionnaire-2 score (SF-MPQ-2s), and follow-up interventions.

RESULTS

Both groups experienced a reduction in the incidence of clinically meaningful ZAP after the intervention therapy. In the R-PRF group, there were 36 cases of clinically meaningful ZAP within the first month post-treatment, while the PRF + PVB group had 38 cases. The incidence of clinically meaningful ZAP, as determined by multivariable generalized estimating equations, was 42.86% in the R-PRF group and 57.58% in the PRF + PVB group during the first month of follow-up. There was a significant difference in the incidence of clinically meaningful ZAP between the two groups after 1 month of treatment (adjusted odds ratio: 0.40; 95% confidence interval: 0.18-0.91; p = 0.03).

CONCLUSIONS

Both R-PRF and PRF + PVB treatments effectively relieve pain in patients with acute/subacute ZAP. However, R-PRF may have superior efficacy compared to PRF + PVB in reducing the incidence of clinically meaningful ZAP 1 month after treatment.

Suppression of neuropathic pain in the circadian clock-deficient Per2m/m mice involves up-regulation of endocannabinoid system

Neuropathic pain often results from injuries and diseases that affect the somatosensory system. Disruption of the circadian clock has been implicated in the exacerbation of the neuropathic pain state. However, in this study, we report that mice deficient in a core clock component Period2 (Per2m/m mice) fail to develop tactile pain hypersensitivity even following peripheral nerve injury. Similar to male wild-type mice, partial sciatic nerve ligation (PSL)-Per2m/m male mice showed activation of glial cells in the dorsal horn of the spinal cord and increased expression of pain-related genes. Interestingly, α1D-adrenergic receptor (α1D-AR) expression was up-regulated in the spinal cord of Per2m/m mice, leading to increased production of 2-arachidonoylglycerol (2-AG), an endocannabinoid receptor ligand. This increase in 2-AG suppressed the PSL-induced tactile pain hypersensitivity. Furthermore, intraspinal dorsal horn injection of adeno-associated viral vectors expressing α1D-AR also attenuated pain hypersensitivity in PSL-wild-type male mice by increasing 2-AG production. Our findings reveal an uncovered role of the circadian clock in neuropathic pain disorders and suggest a link between α1D-AR signaling and the endocannabinoid system.

Public health impact of recombinant zoster vaccine for prevention of herpes zoster in US adults immunocompromised due to cancer

Individuals who are immunocompromised (IC) due to therapy or underlying disease are at increased risk of herpes zoster (HZ). This study evaluates the public health impact of recombinant zoster vaccine (RZV) relative to no HZ vaccination for the prevention of HZ among adults aged ≥18 years diagnosed with selected cancers in the United States (US). A static Markov model was used to simulate three cohorts of individuals who are IC with cancer (time horizon of 30 years; one-year cycle length): hematopoietic stem cell transplant (HSCT) recipients, patients with breast cancer (BC; a solid tumor example), and patients with Hodgkin's lymphoma (HL; a hematological malignancy example). Cohort sizes reflect the estimated annual incidence of each condition in the US population (19,671 HSCT recipients, 279,100 patients with BC, and 8,480 patients with HL). Vaccination with RZV resulted in 2,297; 38,068; and 848 fewer HZ cases for HSCT recipients, patients with BC, and patients with HL, respectively (each versus no vaccine). Vaccination with RZV also resulted in 422; 3,184; and 93 fewer postherpetic neuralgia cases for HSCT, BC, and HL, respectively. Analyses estimated the quality-adjusted life years gained to be 109, 506, and 17 for HSCT, BC, and HL, respectively. To prevent one HZ case, the number needed to vaccinate was 9, 8, and 10, for HSCT, BC, and HL, respectively. These results suggest RZV vaccination may be an effective option to significantly reduce HZ disease burden among patients diagnosed with selected cancers in the US.

Efficacy of High-Voltage Pulsed Radiofrequency in Zoster-Associated Pain: A Meta-Analysis and Systematic Review

Background

Zoster-associated pain (ZAP) is often refractory to conventional treatments and can seriously affect patients' physical and mental health. High-voltage pulsed radio frequency (H-PRF) is a new method for treating ZAP with pulse voltages above 60 V or even up to 100 V. The purpose of this paper was to conduct a systematic review and meta-analysis to evaluate the efficacy of H-PRF in the management of ZAP.

Methods

PubMed, Embase, and the Cochrane library were searched from their inception to June 2022 to identify controlled trials which evaluated the effectiveness of H-PRF compared with standard PRF and sham operations. The primary outcome was pain scores at different treatment times. The secondary outcomes included SF-36 scores, rescue analgesic dose, and side effects.

Results

We reviewed 6 randomized controlled trials involving 428 patients. There was no significant difference between the H-PRF and standard PRF pain scores at 1 week after surgery and the sham operation group at 1 month. At 1, 3, and 6 months, the H-PRF group had better pain score than the standard PRF group, and at 3 months, the pain score was better than the sham operation group. The H-PRF group showed improvement in the SF-36 score, and there were no significant complications in the H-PRF group.

Conclusions

H-PRF is an effective and safe treatment method that has better effects in relieving pain and improving the quality of life and physical and mental health. Although H-PRF provides pain relief rates comparable to those of the control group in the early stages, it remains the preferred and alternative treatment for relieving herpes zoster-related pain.

Novel Bipolar High-Voltage Pulsed Radiofrequency Targeting the Cervical Sympathetic Chain for Treating Acute Herpetic Neuralgia

INTRODUCTION

Postherpetic neuralgia (PHN) in the oral, maxillofacial, neck, and upper limb regions is a refractory neuropathic pain and severely affects the quality of life of patients. Because of the absence of ideal treatments for this condition, relieving pain in the acute stage and preventing the occurrence of PHN are of great clinical significance. However, the optimal intervention for this acute herpetic neuralgia remains obscure.

OBJECTIVES

This study aimed to investigate whether bipolar high-voltage pulsed radiofrequency (PRF) targeting the cervical sympathetic chain could effectively treat acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions and reduce the incidence of PHN.

MATERIALS AND METHODS

A total of 60 patients with acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions were enrolled. The radiofrequency group (n = 30) received bipolar high-voltage PRF under ultrasound guidance at the level of the transverse processes of C6 and C7 to modulate the cervical sympathetic chain. In the sham group (n = 30), the electrodes were simply placed at the same position as in the radiofrequency group, but no radiofrequency energy was applied. The same treatment was repeated in each group after 72 hours. If patients were reported to have a visual analog scale (VAS) score ≥4, they would receive oral tramadol and gabapentin as rescue analgesics. The VAS score, Pittsburgh Sleep Quality Index (PSQI), 36-Item Short Form Health Survey (SF-36) score, use of tramadol and gabapentin, incidence of PHN, and adverse reactions were recorded to assess the effect and safety of therapy during three months of follow-up.

RESULTS

Decreased VAS scores, PSQI scores, and improved SF-36 scores were detected in the two groups at different time points after treatment (all p < 0.05). The VAS scores, PSQI scores, use of tramadol and gabapentin, and incidence of PHN were significantly lower, whereas the SF-36 scores were significantly higher in the radiofrequency group than in the Sham group (all p < 0.05). No serious adverseness related to the treatment was detected in either group.

CONCLUSIONS

Bipolar high-voltage PRF treatment targeting the cervical sympathetic chain could effectively relieve acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions and reduce PHN incidence. The efficacy and safety of this novel treatment make it worthy of recommendation for clinical application.

Efficacy and safety of the recombinant zoster vaccine: A systematic review and meta-analysis

In this systematic review with meta-analysis, the efficacy, effectiveness, and safety of the new GSK recombinant zoster vaccine (RZV) were assessed.Twenty three publications reporting on 14 studies were selected, including 2 pivotal RCTs in older immunocompetent adults (ZOE-50 and ZOE-70), 4 RCTs on immunocompromised patients (haematopoietic stem cell transplantation (HSCT), haematological malignancies, solid tumour, and renal transplantation), and 8 observational studies. Vaccine efficacy of RZV against herpes zoster (HZ) and postherpetic neuralgia (PHN) was very high in immunocompetent older adults (respectively 94% and 91.2% in adults ≥50 years and 91.3% and 88.8% in adults ≥70 years). However, the number needed to vaccinate (NNV) was relatively high (between 32 and 36 for HZ and between 261 and 335 for PHN). Slow waning of the vaccine efficacy has been described after a median follow-up of 10 years after vaccination. In patients after HSCT, vaccine efficacy of RZV against HZ was lower compared to immunocompetent adults (68.2%), while vaccine efficacy of RZV against PHN was similar (89.3%). Higher incidences of HZ and PHN in patients after HSCT resulted in higher absolute reduction of cases and lower NNV (respectively 10 and 115). Observational studies confirmed a good vaccine effectiveness, albeit lower than in RCTs (ranging between 70% and 85%). No safety signal was identified neither in RCTs with immunocompetent or immunocompromised adults nor in observational studies and post-marketing surveillance. Increased reactogenicity after RZV vaccination, limited in extent and duration, did not result in low second dose compliance.

Conclusion

Although vaccine efficacy in RCTs and effectiveness in the real world has been reported to be good, it needs to be stressed that high numbers of immunocompetent adults need to be vaccinated to prevent HZ and PHN. Due to higher incidence, more acceptable NNVs were calculated in immunocompromised adults after HSCT.

Impact of Type 1 Versus Type 2 Diabetes on Developing Herpes Zoster and Post-herpetic Neuralgia: A Population-based Cohort Study

Type 2 diabetes is associated with an increased risk of herpes zoster and postherpetic neuralgia. However, the association of type 1 diabetes with herpes zoster or postherpetic neuralgia remains unclear. This retrospective cohort study using Taiwan's Health Insurance Research Database included 199,566 patients with type 1 diabetes and 1,458,331 with type 2 diabetes, identified during the period 2000 to 2012. Patients with type 1 diabetes had a significantly higher risk of developing herpes zoster than those with type 2 diabetes (p < 0.001). Across all age groups, the impact of diabetes on herpes zoster was greater in type 1 than in type 2 diabetes. Patients with both type 1 and type 2 diabetes had a 1.45-fold higher risk of post-herpetic neuralgia than those without diabetes (hazard ratio 1.45, 95% confidence interval 1.28-1.65; hazard ratio 1.45, 95% confidence interval 1.37-1.52, respectively), and there was no difference between the 2 types of diabetes (hazard ratio 1.06; 95% confidence interval 0.93-1.21). The results recommend consideration of herpes zoster vaccination at an earlier age in patients with type 1 diabetes.

Efficacy and effectiveness of Herpes zoster vaccination in adults with diabetes mellitus: a systematic review and meta-analysis of clinical trials and observational studies

AIM

The risk for Herpes zoster (HZ) and its complications is higher in people with diabetes mellitus (DM). Our aim is to assess efficacy and effectiveness of the currently available live-attenuated zoster vaccine (LZV) and recombinant zoster vaccine (RZV) in adults with DM.

METHODS

A Systematic Review and Meta-analysis of clinical trials and observational studies comparing incidence of HZ and its complications in vaccinated and unvaccinated people with DM was performed, on PubMed, Cochrane, Clinical Trials.gov and Embase databases, up to January 15th, 2023. Risk of bias was assessed through the Cochrane Collaboration tool and the Newcastle-Ottawa Scale. The protocol was registered on the PROSPERO website (CRD42022370705).

RESULTS

Only three observational studies reported LZV efficacy and effectiveness in people with DM. A lower risk for HZ infection (MH-OH Ratio 95% CI = 0.52 [0.49, 0.56] was observed, for unadjusted analysis, and 0.51 [0.46, 0.56] for adjusted analysis, both with P < 0.00001 and no heterogeneity). No data on LZV safety were reported. A pooled analysis of two trials comparing RZV and placebo, showed a reduced risk for HZ incidence: (95% CI Odds Ratio: 0.09 [0.04-0.19]), with no difference in severe adverse events and mortality.

CONCLUSIONS

In our meta-analysis of three observational studies LZV showed a 48% effectiveness in reducing HZ incidence in adults with diabetes whereas in a pooled analysis of two RCTs, RZV showed a 91% efficacy. No data are available on the effects of vaccination on the incidence and severity of HZ-related complications among subjects with diabetes.

Infectious Neuropathies

OBJECTIVE

This article discusses the clinical manifestations and management of infectious peripheral neuropathies.

LATEST DEVELOPMENTS

Several infectious etiologies of peripheral neuropathy are well-recognized and their treatments are firmly established. The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with several central and peripheral nervous system manifestations, including peripheral neuropathies. Additionally, some COVID-19 vaccines have been associated with Guillain-Barré syndrome. These disorders are an active area of surveillance and research. Recent evidence-based guidelines have provided updated recommendations for the diagnosis and treatment of Lyme disease.

ESSENTIAL POINTS

Infectious agents of many types (primarily bacteria and viruses) can affect the peripheral nerves, resulting in various clinical syndromes such as mononeuropathy or mononeuropathy multiplex, distal symmetric polyneuropathy, radiculopathy, inflammatory demyelinating polyradiculoneuropathy, and motor neuronopathy. Knowledge of these infections and the spectrum of peripheral nervous system disorders associated with them is essential because many have curative treatments. Furthermore, understanding the neuropathic presentations of these disorders may assist in diagnosing the underlying infection.

Exploring the prevalence, characteristics and nursing assessment of neuropathic pain

Neuropathic pain results from damage to the nerves. It affects many in the general population, but its prevalence is higher in certain groups, for example those who have undergone certain procedures or systemic anti-cancer therapy and people with conditions such as diabetes mellitus, viral infections or central nervous system disorders. Regardless of the cause, neuropathic pain can have significant adverse effects on people's quality of life, so nurses need to be able to conduct a holistic pain assessment that incorporates physical, emotional, social and spiritual aspects. This article explores the prevalence, characteristics and nursing assessment of neuropathic pain with the aim of improving nurses' awareness, practice and care of people affected by this type of pain.