Assessment of changes in color and size of vitiligo lesions during treatment with narrow band ultraviolet B.

Background: Many treatment modalities have been used to stabilize vitiligo and induce repigmentation. Several methods were used to monitor the color changes inside the treated lesions such as spectroscopes and colorimeters that measure the melanin index inside the lesion.

Objective: To study whether the colorimeter and point counting technique can be used as objective methods in monitoring vitiligo lesions during treatment with Nb-UVB.

Methods: Twenty randomly chosen patients with non-segmental vitiligo were enrolled in this interventional study. Vitiligo disease activity score was recorded in each patient. Patients received Nb-UVB three times per week for 6 months. Two lesions were chosen in each patient, and each lesion was assessed for size using point counting technique and degree of color using the Dermacatch at the beginning of the treatment and evaluated for changes in color and size every 4 weeks till the end of the treatment.

Results: After 6 months of treatment, regarding the lesion size, 90% of lesions showed variable degrees of repigmentation and 10% showed increase in size, indicating increased activity of the disease, and regarding to color changes. We noticed that after one month of Nb-UVB treatment, there is marked increase in MI measurements in many lesions before any clinical improvement appeared, while at the end of treatment, inside the lesion; 95% showed an increase in melanin index and 5% showed no elevation. While the color changes outside the lesion showed 75% of lesions increased in melanin index, 15% remained unchanged and 10% of the lesions showed decrease in melanin index.

Conclusion: Colorimeter was able to detect change in color after only one month of treatment before it was clinically apparent which means that it can be used as a prognostic tool.