Phototherapy with Narrow-Band Ultraviolet B in Adult Psoriasis: A Study in Clinical Practice

Introduction: Large prospective studies evaluating efficacy of narrow band ultraviolet B (NB-UVB) in psoriasis in terms of PASI75 and PASI90 are scarce in the literature. Material and methods: A prospective, open and observational study was conducted. Patients treated with narrow band ultraviolet B (NB-UVB) for psoriasis was included. Treatment target was a reduction of 90% from basal PASI (PASI90), but if patients did not achieve this response after 20 sessions, treatment was continued until PASI75 clearance was achieved. Patients were followed up and relapses were retreated with the same PASI at the first time. Relation between PASI before treatment and total doses needed to achieve PASI75 or PASI90 was studied. Results: Among the 242 patients that received NB-UVB for psoriasis, 102 had guttate psoriasis (GP) and 122 had plaque psoriasis (PP). PASI90 was achieved in 89.1% of patients with GP and 64,8% of patients with PP. Response was significantly better (p<0.05) in GP patients. Retreated patients affected of PP needed the same doses as the first treatment received (p>0.005). Patients with higher PASI need more doses to clear up. Conclusion: Phototherapy with NB-UVB is significantly more effective in patients with GP than patients with PP. Patients retreated seems to need the same doses. Initial PASI can predict the total doses needed to achieve PASI75 or PASI90.