Long-term Durability of Narrowband Ultraviolet B-induced Repigmentation in Non-segmental Vitiligo: A Retrospective Study.

Narrowband ultraviolet B (NB-UVB) phototherapy is a well-established vitiligo treatment. However, limited data exist on the long-term effects of NB-UVB-induced repigmentation. This study evaluated the long-term durability of repigmentation achieved through NB-UVB phototherapy for up to 1 year in 176 patients with non-segmental vitiligo. Demographic and clinical variables, including age, gender, skin phototype, body site involvement, treatment duration, cumulative radiation dose, and clinically significant repigmentation response, were collected. Clinically significant repigmentation was defined as ≥ 50% repigmentation of vitiligo-affected areas, while a durable response was repigmentation lasting ≥ 6 months post-treatment. Of the 176 patients, 80 (45%) achieved clinically significant repigmentation, with the highest success rates observed in the face and neck region (53%). Among responders, 76 (95%) patients maintained their response for ≥ 6 months post-treatment discontinuation, and 47 (59%) sustained repigmentation for > 72 months. Additionally, ≥ 50% repigmentation, longer treatment duration (> 18 months), and higher cumulative radiation dose (> 356 J/cm²) were associated with a durable repigmentation response. NB-UVB phototherapy provides lasting repigmentation in non-segmental vitiligo, with many patients maintaining results for > 6 years. Clinically significant response post-NB-UVB phototherapy, prolonged treatment duration, and cumulative radiation dose are key factors associated with long-term repigmentation.