 Patients with moderate to severe psoriasis who have received treatment with adalimumab loading dose of 80 mg and thereafter 40 mg s.c. biweekly for at least 6 weeks without a PASI reduction of 75 or greater qualify for the study. Adalimumab is continued and UVB-311nm phototherapy is added at 6 weeks or thereafter one a randomized body half left or right; head exempt 3 x per week until complete response defined as reduction in PASI to 3 for a maximum of another 6 weeks until week 12. PASI score, visual analogue score VAS patient score for therapeutic response, and VAS patient score for severity of skin lesions is assessed weekly; and at follow-up visits at month 3, 6, and 12. Paired Wilcoxon testing for differences in PASI and patient VAS scores is done; Fischer exact test is applied to determine differences in complete remission, PASI reduction 90, 75 andor 50 between body sites. 