Higher NB-UVB Phototherapy Intensity Linked to Better Outcomes in Non-Segmental Vitiligo

A single-center retrospective study from UC Davis suggests that higher-intensity narrowband ultraviolet B (NB-UVB) phototherapy is associated with improved treatment response in patients with non-segmental vitiligo, offering practical insight into optimizing treatment protocols.

“NB-UVB phototherapy is a well-established first-line treatment for non-segmental vitiligo,” the investigators noted. “The objectives of this study were to evaluate phototherapy, dosing, outcomes, and predictors of response in non-segmental vitiligo in a 6-year single-site retrospective study.” 

Researchers conducted a retrospective review of an International Review Board-approved REDCap registry including patients treated with NB-UVB phototherapy between 2019 and 2025. Patients with available facial or total Vitiligo Area Scoring Index (VASI) data at baseline and within 12 months of treatment completion were included. Treatment response was defined as ≥50% improvement in VASI (percent change calculated as [VASImax – VASImin] / VASImax. 

Patients who achieved a response consistently received more intensive therapy. Responders had higher total numbers of phototherapy sessions, greater average and cumulative doses, and higher maximum doses compared with non-responders. 

These findings point toward a dose-response relationship in NB-UVB therapy, suggesting that treatment consistency and adequate cumulative exposure may be key drivers of repigmentation outcomes in clinical practice.

“Vitiligo patients who responded to NB-UVB phototherapy generally received higher total sessions, average doses, cumulative doses, and maximum doses compared with non-responders,” the authors reported. “These findings suggest that phototherapy regiments be designed to maximize consistency and dosage.” 

These real-world data reinforce the importance of optimizing phototherapy intensity and adherence to improve outcomes in non-segmental vitiligo.

Reference

Le NT, Huang V. Higher treatment intensity associated with improved outcomes in non-segmental vitiligo phototherapy. Presented at: American Academy of Dermatology Annual Meeting; March 27–31, 2026; Denver, Colorado.