Impact of Early Pain Clinic Consultation and Underlying Conditions on Postherpetic Neuralgia Outcomes

OBJECTIVES: Postherpetic neuralgia (PHN) is a common and debilitating complication of herpes zoster (HZ). We evaluated whether earlier pain-clinic consultation was associated with improved PHN outcomes, including incident PHN, recurrence, and pain response. METHODS: In a ten-year retrospective cohort, we included adults with dermatologist-confirmed HZ referred for pain-clinic consultation. Patients were classified as having early (≤14 d from HZ diagnosis) or late/no consultation. After 1:1 propensity score matching (n=200 per group), we compared incident PHN, defined as persistent dermatomal pain at ≥90 days with numerical rating scale (NRS) ≥3, PHN recurrence, and clinically meaningful pain improvement (NRS decrease ≥2). PHN was adjudicated using structured NRS documentation and clinician notes; standardized neuropathic pain questionnaires were not routinely available. RESULTS: Compared with the late or no consultation group, the early consultation group showed lower incident PHN (RR 0.60, 95% CI 0.38-0.96, P=0.010), lower recurrence (RR 0.50, 95% CI 0.24-0.94, P=0.030), and greater pain improvement (RR 1.33, 95% CI 1.17-1.52, P <0.001). In adjusted models, late consultation (odds ratio [OR] 2.10, 95% CI 1.23-3.59) and autoimmune disease (OR 2.71, 95% CI 1.05-6.99) were associated with higher PHN risk. DISCUSSION: Earlier pain-clinic consultation was associated with lower PHN incidence and greater pain improvement, with a similar direction of effect for recurrence. These findings should be interpreted as a care-pathway association rather than a direct treatment effect, because referral timing may also reflect patient, physician, and health-system factors.