Tawfik NZ, et al. - Colorimeter can be employed as a prognostic tool for vitiligo patients because it allowed detection of change in color of vitiligo lesions after only one month of Nb-UVB treatment before it was clinically apparent.

• This interventional study included 20 patients with non-segmental vitiligo treated with Nb-UVB three times per week for 6 months.

• Post-6 months of treatment, concerning the lesion size, 90% of lesions demonstrated variable degrees of repigmentation, and increase in size was evident in 10%, suggesting elevated disease activity, and regarding color changes.

• Marked increase in MI measurements in many lesions prior to the appearance of any clinical improvement was observed after one month of Nb-UVB treatment.

• At the end of treatment, inside the lesion; 95% exhibited an elevation in melanin index and 5% demonstrated no increase.

• Outside the lesion; 75% of lesions increased in melanin index, 15% were unaltered and 10% of the lesions exhibited reduction in melanin index.