Development and validation of the Vitiligo Extent Score for a Target Area ( <scp>VESTA</scp> ) to assess the treatment response of a target lesion

Since localized treatment for vitiligo is as essential as systemic treatment, a reliable instrument for target evaluation is needed besides those for whole body evaluation. We developed the Vitiligo Extent Score for a Target Area (VESTA) using reference images of both marginal and perifollicular repigmentation to measure the repigmentation rate (%) in a target lesion. In the validation study, a total of 65 dermatologists in 10 institutes evaluated 17 pairs of vitiligo images (pre- and post-treatment) using both a rough estimate and the VESTA. The VESTA (concordance correlation coefficient: 0.949, 95% confidence interval [CI] 0.942-0.955) was significantly more accurate than the rough estimate (0.896, 95% CI: 0.883-0.908). It was also associated with better inter-rater reliability over the rough estimate, albeit not significant. The VESTA can afford intuitive, convenient, and reliable assessment of the treatment response in a target area, and would be useful in clinical practice as well as retrospective studies.