Dynamic observation of repigmentation in vitiligo lesions after narrow-band ultraviolet B phototherapy by using an adhesive tape stripping technique

Abstract

Objective To observe the changes of melanin granules in superficial corneocytes in vitiligo lesions after irradiation with narrow-band ultraviolet B (NB-UVB) by using an adhesive tape stripping technique.Methods Vitiligo lesions were selected from 6 patients and irradiated with NB-UVB every other day for 31 sessions.Superficial corneocytes were obtained by an adhesive tape stripping technique from the vitiligo lesions and perilesional normal skin before every treatment.The morphology,distribution and color of melanin granules were observed after Masson-Fontana silver staining.The percentage of area occupied by melanin granules in superficial corneocytes were calculated by using the Image-Pro Plus 6.0 software.Statistical analysis was conducted by the SPSS11.5 software.Results There were still a few superficial corneocytes containing melanin granules remaining in the vitiligo lesions before treatment.The percentage of area occupied by melanin granules was (5.31 ± 4.12)％ before treatment,(6.24 ± 2.65)％ after 10 treatment sessions,(10.14 ± 5.73)％ after 20 sessions,and (13.05 ± 6.17)％ after 30 sessions,with significant differences between these time points (F =4.334,P ＜ 0.05).Multiple comparisons revealed a significant increase in the percentage of area occupied by melanin granules after 30 treatment sessions compared with those before treatment and after 10 treatment sessions (both P ＜ 0.01 ).The morphology and color of melanin granules in repigmented lesions after treatment differed from those in perilesional normal skin before treatment.Conclusion The adhesive tape stripping technique may serve as a useful tool for the evaluation of repigmentation in vitiligo lesions after phototherapy. Key words: Vitiligo; Ultraviolet therapy; Adhesive tape stripping technique; Melanocytes