Evaluation of 308-nm excimer light therapy for the treatment of palmoplantar pustular psoriasis

We evaluated the efficacy and safety of targeted therapy by excimer light in the treatment of palmoplantar pustular psoriasis in this study. Thera Beam® UV308 is a 308-nm excimer light phototherapydevice which is equipped with a newly developed filter cutting off unwanted short wavelength light. Eight patients with PPP were recruited for this study, who completed a total of 16 treatments with this device once weekly. Clinical response was evaluated by the Palmoplantar Pustular Psoriasis Area and SeverityIndex (PPPASI) everyfour weeks. The results demonstrated that the average PPPASI score before treatment was 10.8. The mean PPPASI score was then reduced to 8.7 at 4 weeks, 6.5 (p<0.05) at 8 weeks, 4.6 (p< 0.01) at 12 weeks, and 4.2 (p<0.01) at 16 weeks after starting treatment, indicating significant improvement. The patients received a mean cumulative dose of 12.4 ± 4.2 J/cm² with a mean final single dose of 1100 ± 334 mJ/cm², showing no severe side effects. These findings indicate that 308-nm excimer light therapyusing Thera Beam® UV308 was effective for palmoplantar pustular psoriasis.