Calcitriol vs. dithranol in combination with narrow‐band ultraviolet B (311 nm) in psoriasis

Summary Background  Narrow‐band ultraviolet (UV) B (311 nm) phototherapy is an effective treatment for psoriasis. In order to reduce cumulative UV doses and to enhance clearance of psoriasis plaques, combination therapies with topical agents such as dithranol and calcipotriol have been established. Objectives  To compare the clinical efficacy, in a half‐side manner, of UVB (311 nm) in combination with either calcitriol or dithranol. Methods  Ten patients with symmetrical stable plaque psoriasis were treated with narrow‐band UVB (311 nm) five times a week. In addition, topical calcitriol was applied twice daily to one arm, whereas the other arm and the rest of the body were treated once daily with dithranol. The follow‐up period was at least 4 weeks. Efficacy was assessed separately for both arms prior to treatment and once weekly thereafter by a modified Psoriasis Area and Severity Index (PASI) score. The cumulative irradiation dose and the number of treatment sessions required for clearance of psoriasis lesions were determined for each patient. Additionally, all patients completed a quality of life questionnaire. Results  Both treatment modalities notably reduced the PASI score. A clinical comparison of UVB (311 nm) in combination with either calcitriol or dithranol revealed no significant therapeutic differences between the regimens. Conclusions  Combination of narrow‐band UVB (311 nm) therapy with calcitriol is equally effective as the combination with dithranol for the treatment of psoriasis. However, patients preferred calcitriol rather than dithranol when both quality of life and treatment acceptability were assessed.