308 nm Excimer Laser Combined With JAK Inhibitors for Adult Localized Non‐Segmental Vitiligo: A Multicenter Randomized Controlled Trial

ABSTRACT Background Vitiligo is an acquired depigmenting skin disorder characterized by autoimmune‐mediated melanocyte destruction, leading to well‐defined depigmented macules and patches. Localized non‐segmental vitiligo poses a significant therapeutic challenge. Methods A total of 251 patients with localized refractory non‐segmental vitiligo were randomized into four groups: combination therapy group (308 nm excimer laser + Janus kinase [JAK] inhibitors, n = 63), JAK inhibitor monotherapy group ( n = 63), 308 nm excimer laser group ( n = 63), and positive control group ( n = 62). Treatment lasted 52 weeks. Therapeutic responses were assessed using the Vitiligo Area Scoring Index (VASI) and dermoscopy before and after treatment. Mixed‐effects models compared efficacy and analyzed influencing factors. Fisher's exact test compared efficacy among groups and sites; Kruskal–Wallis test assessed melanocyte island density changes; chi‐square test evaluated pigmentation stability and recurrence at the 1‐year follow‐up. Results Combination therapy with 308 nm excimer laser and oral JAK inhibitor baricitinib showed significantly greater efficacy than monotherapy and conventional treatment, with a 14.20% higher repigmentation rate than the positive control group ( p < 0.001), indicating synergistic effects. By Week 4, patients with melanocyte island density ≥ 5/cm 2 had markedly better repigmentation, supporting dermoscopy as an early predictive and monitoring tool. Mixed‐effects analysis showed higher repigmentation in facial versus non‐facial lesions, females vs. males, and reduced efficacy with longer disease duration. At the 1‐year follow‐up, combination therapy maintained stable pigmentation with no recurrence. Conclusion The combination of 308 nm excimer laser and JAK inhibitors significantly enhances repigmentation efficiency in adult localized non‐segmental vitiligo, particularly in patients with shorter disease duration and early formation of pigment islands.