What is targeted laser phototherapy?

An excimer (XeCl) laser, which emits a wavelength of 308 nm (near the narrowband UVB wavelength of 311 nm) is effective in treating individual psoriatic plaques. Supererythemogenic doses, from 6 to 8 MEDs, are used on individual plaques for 8 to 12 treatments and may induce months of remission. This localized form of UVB phototherapy is also an effective treatment for patches of vitiligo. It is advantageous in that it avoids irradiating healthy, nonlesional skin. It more effectively induces T-cell apoptosis, as well. In psoriasis, it is able to target individual plaques with higher fluences and reaches deeper T cells within the dermis. The pulsed dye laser at 585 to 595 nm has also been shown to be efficacious in treating individual psoriatic plaques, but appears less effective than the 308 nm excimer laser.


Nicolaidou E, Antoniou C, Stratigos A, Katsambas AD: Narrowband ultraviolet B phototherapy and 308-nm excimer laser in the treatment of vitiligo: a review, J Am Acad Dermatol 60:470–477, 2009.

Zakarian K, Nguyen A, Letsinger J, Koo J: Excimer laser for psoriasis: a review of theories regarding enhanced efficacy over traditional UVB phototherapy, J Drugs Dermatol 6:794–798, 2007.