P111 Evaluating the performance of the Vitiligo Signs of Activity Score using prospective photographically documented vitiligo activity

Abstract

The Vitiligo Signs of Activity Score (VSAS) has been developed as a clinician-observed score to quantify clinically visible signs of vitiligo activity. However, its performance in measuring vitiligo activity has not been studied in detail. The aim of this study was to evaluate VSAS as a tool to measure vitiligo activity. This was a post hoc analysis of a randomized trial comparing oral betamethasone minipulse vs. oral tofacitinib in active vitiligo. VSAS and Vitiligo Disease Activity Score (VDAS) and Vitiligo Disease Improvement Score were evaluated on standardized whole-body photographs by two blinded evaluators. VDAS 60 (≥ 60% improvement from baseline) at 3 months was used as a marker of recent vitiligo activity. Vitiligo was categorized as active or stable (no new lesions or extension since last visit) by an independent expert based on comparison of sequential photographs. For the 54 enrolled patients, data were available for 48 patients at 1 month, 43 patients at 3 months and 41 patients at 6 months. Mean total VSAS showed a positive correlation with VDAS 60 at 3 months (r = 0.34, P = 0.02). Of the subscores, only VSAS-h (hypochromic areas) showed a statistically significant correlation (r = 0.42, P = 0.005) with VDAS 60. No statistically significant correlation was seen between VSAS and the number of new vitiligo macules at 1 month (r = 0.04, P = 0.77) or 3 months (r = 0.09, P = 0.56). The mean (SD) total VSAS was comparable between active and stable vitiligo at 1 month [7.80 (3.43) vs. 8.33 (3.94), P = 0.62] and 3 months [7.80 (3.99) vs. 8.15 (3.28), P = 0.78]. Mean VSAS subscores also showed similar nonsignificant changes. The mean (SD) total VSAS scores declined significantly at 6 months in patients whose disease became stable [9.4 (2.9) vs. 6.3 (3.6), P < 0.001], but not in those whose disease remained active [6.3 (6.5) vs. 5 (5), P = 0.27]. VSAS showed a weak-to-moderate positive correlation with graded vitiligo activity, but could not discriminate between active and recently stabilized vitiligo as a cross-sectional measure. VSAS was responsive to decrease in vitiligo activity.