Ultraviolet B (UVB) Phototherapy in the Treatment of Vitiligo

Vitiligo is a common, acquired pigmentary disorder of unknown pathogenesis that presents a therapeutic challenge to many dermatologists (Figure 1). Although surgery in the form of grafting or transplantation is generally the most definitive treatment option, these procedures are limited by concerns of post-procedure cosmesis. Photochemotherapy using psoralen and ultraviolet A (PUVA) therapy, topical and oral immunosuppresants, as well as cosmetic camouflage are also commonly employed with varying clinical efficacy. Phototherapy is a popular treatment option, which includes both of the generalized ultraviolet B (UVB) therapies, broadband UVB (BB-UVB) and narrowband UVB (NB-UVB). The UVB-based therapeutic modalities in development are targeted delivery of BBand NBUVB, monochromatic excimer light (MEL), microphototherapy, and combination therapy. In particular, the sophisticated devices that utilize MEL can emit coherent 308-nm radiation using the xenon chloride (XeCl) excimer laser or microphotography, while incoherent radiation can be supplied by various lamp and light systems. All of the UVB phototherapy modalities can be used in combination with topical or systemic agents, thus further expanding treatment options for vitiligo patients.