Prednisolone 20 mg vs 40 mg in complex regional pain syndrome type I: A randomized controlled trial

Background: High dose of corticosteroid has been found beneficial in complex regional pain syndrome type I (CRPS-I). We report the efficacy and safety of prednisolone 20 mg versus 40 mg in CRPS-I in an open label randomized controlled trial.

Methods: The patients with CRPS-I of the shoulder joint with a CRPS score of ≥8 were included. Their demographic details, comorbidities, and underlying etiology were noted. The severity of CRPS was assessed using a 0-14 CRPS scale, the pain using a 0-10 Visual Analogue Scale (VAS), and sleep quality using a 0-10. Daily Sleep Interference Scale (DSIS). Patients were randomized to prednisolone 40 mg/day (group I) or 20 mg/day (group II) for 14 days, then tapered to 10 mg in group I and to 5 mg in group II by 1 month. Thereafter both groups received prednisolone 5 mg/day for 2 months. The primary outcome was a >50% reduction in VAS score, and secondary outcomes were a reduction in CRPS score, DSIS score, and adverse events.

Results: Fifty patients were included, and their baseline characteristics were comparable. At one month, all the patients had >50% reduction in the VAS score. The effect size was 0.38 (95% CI 0.93-0.20; p = 0.20). On the Kaplan-Mayer analysis, the improvement in the VAS score (Hazard ratio-1.43, 95 % CI-0.80-2.56, p = 0.22) and the CRPS score (HR-0.79,95 % CI-0.45-1.39; p = 0.41) was insignificant between the two groups. The DSIS score improved in group II (HR-1.85,95 % Cl-1.04-3.31,p = 0.04). Group I patients needed frequent adjustment of antidiabetic drugs (14 vs 6; p = 0.04).

Conclusion: The efficacy of prednisolone 20 mg is not inferior to 40 mg in CRPS-I, and is safe in diabetic patients.

Limitations: This is an open label randomized controlled trial with small sample size without a placebo arm.