A review of monochromatic excimer light in vitiligo.

Phototherapy is a mainstay of vitiligo treatment and has varying rates of efficacy. Narrowband ultraviolet (UV) B (NB-UVB) and UVA have been used for decades, but it is only recently that monochromatic excimer light (MEL) was developed for use in dermatology and adapted for the treatment of vitiligo. The specific 308-nm radiation wavelength is delivered in a targeted form by the xenon-chloride excimer laser and is also available in an incoherent form that is commonly referred to as the excimer lamp. MEL administered by both laser and lamp has shown efficacy superior to NB-UVB for the treatment of vitiligo and induces more changes at the cellular level than conventional UVB modalities. The excimer laser is effective in adults and children with vitiligo in all skin types as monotherapy or in combination with other established vitiligo therapeutics. Treatment regimens studied included excimer laser two to three times weekly for up to 36 weeks. Patients commonly achieved > 75% repigmentation. The laser has also been used in combination with topical corticosteroids, calcineurin inhibitors and vitamin D analogues, as well as surgery, thus further expanding treatment options for patients with vitiligo. The excimer lamp has been used for treatments one to three times a week for up to 24 weeks and was found to be equal to excimer laser in a head-to-head comparison. It has also been used in combination with topical corticosteroids and oral vitamin E. Both MEL modalities have a limited adverse side-effect profile. Long-term effects are yet to be determined; however, based on available data on UVB phototherapy as well as the properties of MEL devices, there is probably only a minimal increased malignancy risk.