Facial involvement is reflective of patients' global perception of vitiligo extent.

BACKGROUND: The involvement of visible areas in vitiligo has been found to be correlated with increased psychiatric morbidity. Although multiple tools have been developed to assess vitiligo, no cutoff for improvement or worsening of vitiligo from a patient's perspective has been established. OBJECTIVES: To determine the minimal clinically important difference (MCID) of the Self-Assessment Vitiligo Extent Score (SA-VES) in patients with vitiligo and to evaluate, from the patient's perspective, the importance of the change in the involvement of visible areas (face and hands) in patients' overall perception of disease worsening or improving. METHODS: This was a cross-sectional study in the context of the ComPaRe e-cohort. Adult patients with vitiligo were invited to answer online questionnaires. They completed the SA-VES twice, 1 year apart. In addition, patients answered a 5-point Likert anchor question aimed at assessing their perception of the evolution of the extent of their vitiligo. The MCID was calculated using distribution- and anchor-based approaches. Using ordinal logistic regression, the change of vitiliginous lesions on the face or hands was compared to the overall extent of vitiligo (patches on all body areas). RESULTS: In total, 244 patients with vitiligo were included in the analyses; 20 (8%) were found to have an improvement in their vitiligo. The MCID in worsened patients was equal to a 1.3% body surface area [95% confidence interval (CI) 1.01-1.43] increase in the SA-VES. For participants with improved vitiligo, the MCID was equal to a decrease in total SA-VES of 1.3% (95% CI 0.867-1.697). Patients' perceptions of change in their vitiligo was increased sevenfold when it affected the face vs. the rest of the body. CONCLUSIONS: Changes in the facial SA-VES were highly correlated with patients' impressions of the extent of vitiligo.