Calcipotriol vs. tazarotene as combination therapy with narrowband ultraviolet B (311 nm): efficacy in patients with severe psoriasis

BACKGROUND: Phototherapy has been shown to be one of the most effective treatment modalities for patients with psoriasis. Nevertheless, photocombination therapies capable both of reducing cumulative ultraviolet (UV) doses and of accelerating clearance of skin lesions are important and of high interest. There have been no published studies comparing the effect of narrowband UVB irradiation in combination with topical application of tazarotene vs. calcipotriol. OBJECTIVES: To determine, in a half-side manner, whether a combination of UVB (311 nm) and tazarotene is superior to UVB (311 nm) plus calcipotriol or vice versa. METHODS: Ten patients suffering from widespread symmetrical psoriasis were treated for at least 4 weeks with topical calcipotriol and tazarotene in a half-side distribution. Additionally, the whole body was irradiated with narrowband UVB (311 nm) four times a week. Before treatment and once weekly during therapy a modified Psoriasis Area and Severity Index was estimated for each body half. The total treatment time, number of treatment sessions and cumulative UVB dose necessary for clearance of skin lesions were determined in an observer-blind fashion for each patient. Furthermore, all patients completed a quality of life questionnaire. RESULTS: Clearance of psoriasis was observed after a median of 19 treatment sessions (range 14-28) and a median cumulative UVB dose of 22.98 J cm-2 (range 9.24-58.22) simultaneously for both body halves. On the side treated with topical tazarotene gel, four patients complained of itching and dryness of the skin, and skin irritation was observed in three of them. Six patients preferred the application of tazarotene gel, while four preferred calcipotriol. CONCLUSIONS: Our clinical comparison of narrowband UVB with either topical calcipotriol or topical tazarotene revealed no significant therapeutic difference between both regimens. Although these results need to be confirmed in larger patient groups, we feel that both photocombination therapies can broaden the therapeutic options for moderate to severe psoriasis vulgaris and may reduce the cumulative UVB dose during therapy.