Westerhof and Nieuweboer were the first to report the use of NB-UVB for the treatment of vitiligo in 1997. They compared the use of NB-UVB and topical PUVA each administered twice weekly for 4 months. They reported that 67 % of NB-UVB patients developed repigmentation as compared with 46 % of topical PUVA patients [57]. Several subsequent studies by Parsad et al., Bhatnagar et al., and Yones et al. all demonstrated NB-UVB’s superior efficacy on repigmentation compared to PUVA [58–60]. Currently, NB-UVB is used as first-line treatment for patients with widespread vitiligo, not only for its greater clinical efficacy over PUVA but also for the elimination of systemic psoralen-related side effects, the better color match, the superior safety in children, and the relative lack of long-term photocarcinogenesis risk.

The first head-to-head study comparing NB-UVB with excimer laser was conducted by Hong et al. using a split-body study. It was discovered that twice weekly, excimer laser produced more rapid and profound repigmentation than NB-UVB after 10, 15, and 20 treatments each [61]. Casacci et al. conducted another split-body study with twice-weekly dosing of both NB-UVB and excimer lamp for 6 months. The patients receiving excimer lamp treatment achieved faster repigmentation [62]. However, a more recent prospective intra-patient, placebo-controlled, randomized trial conducted by Verhaeghe et al. showed a higher percentage of lesions treated with localized 311 nm NB-UVB achieving 50 % repigmentation as compared with sites treated with 308 nm excimer lamp after 24 sessions [63]. In conclusion, while there are several more studies demonstrating the clinical superiority of excimer laser and excimer lamp to NB-UVB, larger-scale studies need to be conducted to evaluate this further.

A single-center, randomized comparative study by Le Duff et al. compared the efficacy of the excimer laser versus the excimer lamp in the treatment of vitiligo. No statistically significant difference between the two excimer devices was demonstrated. They did note that the lamp takes longer to deliver the same dose as the laser. It also produces more erythema, believed to be due to longer treatment time [64]. Similarly, in 2005, Köllner et al. found no statistically significant difference in the treatment of psoriasis with excimer laser, excimer lamp, and NB-UVB for 10 weeks of treatment [65].

The incidence of skin cancer among vitiligo patients has yielded contradictory results. In 2002, Shallreuter et al. reported no increased risk for sun-induced skin cancers or sun-induced skin damage by biopsy [68]. Hexsel et al. later reported a small increase in the incidence of nonmelanoma skin cancers in vitiligo patients; however, the results were not statistically significant [69]. There is further research to suggest that individuals with vitiligo, including those with prior phototherapy treatment (including NB-UVB and PUVA), have an overall decreased risk in the incidence of both melanoma and nonmelanoma skin cancers as reported by Teuling et al. and Paradisi et al. [70, 71]. Conversely, Nijsten et al. demonstrated that psoriatic patients who underwent PUVA therapy had an increased incidence of nonmelanoma skin cancer, even decades after PUVA treatment [72]. Additional studies need to be conducted for further evaluation.