Quantitative Outcome Assessment of Color Match and the Extent of Repigmentation after Pixel Array Epidermal Grafting for Head and Neck Stable Vitiligo: A Prospective Cohort Study

Background: Epidermal grafting with an automatic harvesting system has been reported as a simple and efficacious procedure for stable vitiligo. However, no prospective cohort study has quantitatively evaluated the color matching and extent of repigmentation in the head and neck area by this method. Objective: To evaluate the color matching and extent of repigmentation after pixel array epidermal grafting by image analysis software and physicians' naked eye. Methods: Ten Asian patients with head and neck vitiligo lesions stable for at least 6 months were treated with pixel array epidermal grafting with an automatic harvesting system and post-grafting phototherapy. The patients were evaluated 1, 3, and 6 months post grafting for the percentage of repigmentation by blinded physicians' assessment and image analysis software. The color matching index of repigmentation was evaluated by measuring the melanin index in the grafted area and the juxta non-vitiliginous area. Results: The average blister harvest time was 46.3 +/- 9.7 min. The area percentile of repigmentation by the image analysis software were 32.3 +/- 26.8, 64.6 +/- 29.4, and 76.5 +/- 25.9 at 1, 3, and 6 months post grafting, respectively. There were no significant differences between the physicians' assessments and the results from the image analysis software. The change in the area percentile of repigmentation between 3 and 6 months post grafting was only statistically significant using image analysis software. The grafted area achieved a color match of 83.1 +/- 13.4% that of the juxta non-vitiliginous area 6 months after grafting. Three patients had repigmentation of leukotrichia. Conclusion: By quantitative measurement, uniform pixel array micrografts provide a very good extent of repigmentation and color match in the head and neck area. Image analysis software revealed a steady increase in repigmentation after POM3 until POM6, which was not detected by subjective assessment.