Targeting Neuroinflammation and Peripheral Nerve Dysfunction in Refractory Postherpetic Neuralgia: A Multimodal Injection Case Series.

BACKGROUND Postherpetic neuralgia (PHN) is a chronic neuropathic pain condition that often persists despite standard pharmacological therapy. Interventional approaches targeting neurogenic inflammation and peripheral nerve dysfunction are increasingly considered in refractory cases. Perineural or epidural steroid injections exert local antiinflammatory effects, whereas 5% dextrose water (5DW) injections have been reported to modulate neural activity and reduce neuroinflammation. However, evidence regarding the combined use of these 2 modalities in PHN remains limited. CASE REPORT Four patients with PHN persisting for more than 3 months and refractory to pharmacological therapy underwent steroid injections (supraorbital, lumbar or thoracic epidural, or stellate ganglion block) combined with intralesional 5DW injections. All procedures were performed under ultrasound guidance. Within 2 to 3 weeks, all patients demonstrated clinically meaningful reductions in pain intensity (>50% reduction in visual analog scale scores), with consistent response patterns across different dermatomal distributions (V1, L2-L3, C4-T4, and T2-T4). No adverse events or procedural complications were observed. CONCLUSIONS The findings of this case series suggest that the combination of steroid and 5DW injections may represent a feasible multimodal approach for refractory PHN, with consistent clinical responses across dermatomes. Although synergistic mechanisms cannot be established based on the present study design, these results provide an initial basis for the hypothesis that simultaneous targeting of neurogenic inflammation and peripheral nerve dysfunction may confer additional benefit. Prospective controlled studies with larger sample sizes are warranted to evaluate comparative effectiveness, durability of benefit, and the positioning of this intervention within PHN management algorithms.