Association of platelet-rich plasma combined with dorsal root ganglion-targeted pulsed radiofrequency with outcomes in subacute thoracic herpes zoster neuralgia: a retrospective cohort study

Background Subacute herpes zoster neuralgia is a clinically important transitional stage before pain becomes fully established as persistent postherpetic neuralgia. Methods In this single-center retrospective cohort study, patients with subacute thoracic herpes zoster neuralgia treated between January 2024 and December 2025 were identified from routine clinical records. Patients were classified according to the treatment received as PRP + PRF or PRF alone. The primary outcome was the Numerical Rating Scale (NRS) score at 3 months after treatment. Repeated NRS and Pittsburgh Sleep Quality Index (PSQI) measurements were analyzed longitudinally. Secondary outcomes included pregabalin requirement and persistent clinically meaningful zoster-related pain, defined as NRS > 3 at the 3-month post-treatment follow-up. Results Seventy patients were analyzed, including 36 in the PRP + PRF group and 34 in the PRF group. At 3 months, the observed mean NRS score was lower in the PRP + PRF group than in the PRF group (1.39 ± 1.44 vs. 2.56 ± 1.02). In the prespecified ANCOVA adjusted for baseline NRS, PRP + PRF was associated with a lower 3-month NRS score than PRF alone (adjusted mean difference, −1.13; 95% confidence interval [CI], −1.71 to −0.54; p < 0.001). The association remained directionally consistent in additional multivariable and change-score sensitivity analyses. Significant group-by-time interactions were observed for NRS and PSQI, with lower NRS and PSQI scores in the PRP + PRF group from 1 week through 3 months. Pregabalin requirement at 3 months was lower in the PRP + PRF group ( p = 0.001). Persistent clinically meaningful zoster-related pain at 3 months occurred in 4 of 36 patients (11.1%) in the PRP + PRF group and 7 of 34 patients (20.6%) in the PRF group ( p = 0.336). Conclusion In this retrospective cohort, PRP combined with DRG-targeted PRF was associated with faster early improvement in pain and sleep and with lower post-treatment pregabalin use than PRF alone. Further prospective studies are needed to confirm these findings and determine whether this approach influences progression to persistent pain and PHN.