[Efficacy and safety of acute-phase transcutaneous auricular vagus nerve stimulation for herpes zoster-related pain in middle-aged and elderly patients with comorbid depression and anxiety].
Objective: To evaluate the efficacy and safety of transcutaneous auricular vagus nerve stimulation (taVNS) during the acute phase in middle-aged and elderly patients with herpes zoster (HZ) comorbid depressive and anxiety states. Methods: This was a randomized controlled trial. Forty middle-aged and elderly patients with acute-phase HZ who attended the Department of Dermatology at Xuanwu Hospital, Capital Medical University, from June 2024 to June 2025 were enrolled and randomly assigned in a 1∶1 ratio using a random number table to receive either taVNS (n=20) or sham stimulation (n=20) for 5 consecutive days. Both groups received antiviral therapy and on-demand rescue analgesia. Pain, anxiety/depression, and sleep quality were evaluated using the Visual Analog Scale (VAS), the 4-item Patient Health Questionnaire (PHQ-4), and the Insomnia Severity Index (ISI), respectively. The primary outcome was the incidence of subacute pain at 30 days post-rash onset. Secondary outcomes included cumulative analgesic consumption at 1 and 2 weeks after treatment, the changes from baseline (Δ values) in PHQ-4 and ISI scores at 2 weeks, and the incidence of postherpetic neuralgia (PHN) at 90 days post-rash onset. Results: In the taVNS group, 7 patients (35%) were female, with a mean age of (64.1±9.7) years; in the sham group, 10 patients (50%) were female, with a mean age of (61.5±8.5) years. There were no statistically significant differences between the two groups in baseline VAS, PHQ-4, or ISI scores (all P>0.05). The incidence of subacute pain was significantly lower in the taVNS group than in the sham group [5% (1/20) vs 35% (7/20), RD=-30.0% (95%CI:-52.1%--4.9%); RR=0.14 (95%CI: 0.02-1.06); P=0.044]. At 2 weeks after treatment, the Δ values of PHQ-4 and ISI in the taVNS group were significantly greater than those in the sham group. The proportion of patients taking Lofentadine and the cumulative Lofentadine consumption at weeks 1 and 2 were both lower in the taVNS group than in the sham group (all P<0.05). No serious adverse events occurred in either group, and the difference in PHN incidence between groups was not statistically significant (P>0.05). Conclusions: Acute-phase taVNS appears to be feasible and safe in middle-aged and elderly patients with HZ and comorbid depressive and anxiety, effectively reducing subacute pain and improving emotional and sleep outcomes.