Transcutaneous Auricular Vagus Nerve Stimulation for Acute Herpes Zoster Pain in Middle-Aged and E

Introduction and study objective

This randomized controlled trial assessed the efficacy and safety of acute-phase transcutaneous auricular vagus nerve stimulation (taVNS) in middle-aged and elderly patients with acute herpes zoster (HZ) who also had comorbid depressive and anxiety symptoms. The investigators aimed to determine whether a short course of taVNS administered during the acute rash phase could reduce the incidence of subacute pain and improve emotional and sleep outcomes.

Study design and patient population

The study enrolled 40 middle-aged and elderly patients with acute-phase HZ who presented to the Department of Dermatology at Xuanwu Hospital, Capital Medical University, and one additional dermatology department between June 2024 and June 2025. Participants were randomized in a 1:1 ratio using a random number table to either the active taVNS group (n = 20) or a sham stimulation group (n = 20).

Baseline characteristics reported in the source included sex and age: the taVNS group comprised 7 women (35%) with mean age 64.1 ± 9.7 years, while the sham group comprised 10 women (50%) with mean age 61.5 ± 8.5 years. Baseline scores for pain, mood, and sleep (measured by VAS, PHQ-4, and ISI) did not differ significantly between groups (all P > 0.05).

Interventions and concomitant treatments

Participants in the active group received taVNS for 5 consecutive days. The control arm received sham stimulation over the same 5-day period. Both groups received standard antiviral therapy and had access to on-demand rescue analgesia. The specific taVNS device parameters and sham procedures were not detailed in the PubMed abstract.

Outcome measures and endpoints

Primary outcome:

• Incidence of subacute pain at 30 days after rash onset.

Secondary outcomes included:

• Cumulative analgesic (lofentadine) consumption at 1 and 2 weeks after treatment.
• Changes from baseline (Δ values) in PHQ-4 and ISI scores at 2 weeks.
• Incidence of postherpetic neuralgia (PHN) at 90 days after rash onset.

Pain, anxiety/depression, and sleep quality were assessed using the Visual Analog Scale (VAS), the 4-item Patient Health Questionnaire (PHQ-4), and the Insomnia Severity Index (ISI) respectively.

Key results: pain, mood, sleep, and analgesic use

Primary outcome:

• The incidence of subacute pain at 30 days was significantly lower in the taVNS group compared with the sham group: 5% (1/20) versus 35% (7/20). The reported risk difference was -30.0% (95% CI: -52.1% to -4.9%), risk ratio 0.14 (95% CI: 0.02–1.06), and P = 0.044.

Mood and sleep:

• At 2 weeks after treatment, the magnitude of improvement from baseline (Δ values) in both PHQ-4 and ISI scores was significantly greater in the taVNS group than in the sham group, indicating better short-term reductions in anxiety/depressive symptoms and insomnia severity with taVNS.

Analgesic consumption:

• The proportion of patients taking lofentadine and the cumulative lofentadine consumption at weeks 1 and 2 were both lower in the taVNS group compared with sham (all P < 0.05), indicating reduced short-term rescue analgesic requirements in the active treatment arm.

Longer-term pain (PHN):

• The incidence of postherpetic neuralgia (PHN) at 90 days did not differ significantly between groups (P > 0.05) in this sample.

Safety and adverse events

No serious adverse events occurred in either the taVNS or sham groups during the study period as reported in the abstract. The authors declared no conflicts of interest. Detailed adverse event profiles or device-related tolerability data were not provided in the abstract.

Conclusions and clinical implications

In this randomized trial of 40 middle-aged and elderly patients with acute HZ and comorbid depressive and anxiety symptoms, a 5-day course of acute-phase taVNS appeared feasible and safe and was associated with a significantly lower incidence of subacute pain at 30 days compared with sham stimulation. taVNS also produced greater short-term improvements in mood (PHQ-4) and sleep (ISI) scores and reduced cumulative lofentadine consumption at 1 and 2 weeks. There was no statistically significant difference in PHN incidence at 90 days in this study.

Clinical interpretation should note the sample size (n = 40) and that device parameters and many procedural details were not reported in the abstract. The findings support further investigation of taVNS as an adjunctive, noninvasive neuromodulation strategy for acute HZ pain in older patients with coexisting mood disturbance, with larger trials and longer follow-up needed to clarify effects on PHN prevention and to better characterize safety and tolerability.