Pilot evaluation of supra-erythemogenic phototherapy with excimer laser in the treatment of patients with moderate to severe plaque psoriasis.

Background: Phototherapy is an effective treatment for generalized plaque psoriasis, but is inconvenient and dosimetry is limited by the minimal erythema dose (MED).

Objective: This pilot study evaluated the efficacy, safety, and feasibility of excimer laser utilizing a supra-erythemogenic phototherapy strategy (phototherapy well beyond the MED dose) to treat generalized psoriasis.

Methods: In this 9-month study, 13 patients with psoriasis involving > 10% but < 30% body surface area received laser treatment twice weekly for 12 weeks, with 6 months of post-treatment follow-up. The primary endpoint was percentage of patients achieving Psoriasis Area and Severity Index (PASI) 75.

Results: Of the 12 patients who completed the treatment phase, 54% achieved PASI 75. During the 6-month follow-up period 83% maintained PASI 50 with no treatment.

Limitations: This pilot study had a small sample size.

Conclusion: The laser is an effective treatment with a favorable remission rate. With enhanced power in the near future, laser is likely to become more promising for generalized psoriasis.