Efficacy and Safety of Blue Light (453 nm) Treatment for Mild Psoriasis Vulgaris Over Three Months Compared to Vitamin D.

Patients will be screened up to 28 days before start of treatment. During the screening visit, the purpose and procedures of the study will be explained to potential patients and informed consent will be obtained. At the baseline visit, all inclusion and exclusion criteria will be re-assessed. Eligible patients will be randomized to treatment of the target area with either 30 minutes (group30) or 15 minutes (group15) blue light at 600 milliwatt per square centimeter (mW/cm²). Additionally, two study areas with similar clinical symptomatology will be determined and will be randomized to blue light treated area and Daivonex (Vitamin D) treated area. After randomization, patients will be trained on a demonstrator device (no actual treatment to ensure investigator is blinded as to which group the patient is randomized to) as well as the Daivonex cream. After patients have been instructed, treatment of the areas will be applied daily (once per day, 5-7 times / week) at home for a treatment period of 12 weeks. During those 12 weeks, patients will return to the study site for safety and effectiveness assessments at week 2, 4, 8 and week 12. A phone call visit will be performed after one week of treatment to check for any adverse events or problems in handling the device or the cream. The visit at week 12 serves as end of treatment visit. The patients will be followed-up for another 4 weeks. Treatment responses will be photo documented.