Abstract / Summary
Abstract Background Acute herpes zoster (HZ) causes severe pain and frequently progresses to postherpetic neuralgia (PHN), especially in middle-aged and older adults with comorbid depressive or anxiety symptoms. Transcutaneous auricular vagus nerve stimulation (taVNS) has emerging analgesic and affective benefits, but its adjunctive value in acute HZ remains unclear. Methods In this prospective, multicenter, observational cohort study (ChiCTR2100045232), 122 adults aged ≥ 50 years with acute HZ and screen-positive depressive and/or anxiety symptoms were enrolled. Sixty-two patients received adjunctive taVNS (30 min, twice daily, 14 days) plus conventional therapy; 60 received conventional therapy alone. The primary outcome was VAS pain score change from baseline to Day 7. Secondary outcomes included responder rates, pain trajectory, 90-day cumulative pain burden, PHN, emotional and sleep outcomes, and rescue analgesic consumption. Results The primary outcome did not differ significantly (adjusted difference 0.33 points; P = 0.245). However, taVNS recipients showed significantly faster pain resolution at Weeks 1 and 2 (both P < 0.05) and lower 90-day cumulative pain burden (93.1 vs 138.3 VAS·days; P = 0.023). Anxiety remitted more rapidly (GEE interaction P < 0.001), with higher Week-2 screen-negative rates (85.1% vs 37.8%; adjusted OR 13.57; P < 0.001). ISI improvement was greater (adjusted difference 3.75 points; P < 0.001). Rescue analgesic consumption was lower (rate ratio 0.40; P = 0.036). PHN at Day 90 was numerically lower (8.1% vs 20.0%; P = 0.128). No serious adverse events occurred. Conclusion Adjunctive taVNS was associated with faster acute pain resolution, lower cumulative pain burden, marked anxiety and sleep improvement, and reduced rescue analgesic use, without serious adverse events. Randomized sham-controlled trials are warranted.