Redefining Vitiligo Severity Assessment: Development and Validation of VEIDI, a Multifaceted Objective Scoring Framework

Vitiligo is a chronic depigmenting disorder characterized by progressive melanocyte loss, resulting in irregular hypopigmented or depigmented lesions. Despite its high prevalence and psychosocial burden, clinical assessment remains largely subjective and insufficiently standardized. Conventional evaluation techniques and existing scoring systems, such as VASI and VETF, are labor-intensive, observer-dependent, and limited in reproducibility. This study introduces VEIDI (Vitiligo Extent, Intensity, and Distribution Index), a comprehensive and objective scoring framework for vitiligo severity assessment. VEIDI integrates illumination-normalized image enhancement using Contrast Limited Adaptive Histogram Equalization (CLAHE), intensity-driven lesion segmentation, lesion-wise geometric characterization, and spatial distribution analysis to quantify disease burden in a standardized and interpretable manner. Clinical evaluation across multiple longitudinal sessions demonstrated high agreement with expert dermatologists, achieving an intraclass correlation coefficient (ICC) of 0.957, a root mean squared error (RMSE) of 0.285, and 99.6% agreement within±1 severity grade. On CPU-only hardware (Intel Core i7, 16GB RAM), VEIDI required 1.18 ± 0.16 s per image for end-to-end automated inference, supporting its practical suitability for near real-time clinical use. VEIDI demonstrates reliability comparable to reported inter-dermatologist agreement levels while significantly reducing evaluation time and observer variability. By providing a robust, reproducible, and clinically interpretable severity score, VEIDI offers a practical framework for objective vitiligo assessment with strong potential for routine clinical use, longitudinal monitoring, and standardized outcome reporting in clinical trials.