A comparison of psoralen plus ultraviolet A (PUVA) monotherapy, tacalcitol plus PUVA and tazarotene plus PUVA in patients with chronic plaque-type psoriasis

Background Numerous studies have shown that the additional administration of topical or systemic antipsoriatic agents might serve as an effective means to increase the efficacy of photochemotherapy [psoralen plus ultraviolet (UV) A (PUVA)] for psoriasis. Objectives To compare the therapeutic response to tacalcitol plus PUVA, tazarotene plus PUVA and PUVA monotherapy in patients with chronic plaque-type psoriasis. In addition, we also assessed the duration of remission induced by each regimen and the tolerability of the two combination treatments. Methods Thirty-one patients with chronic plaque-type psoriasis were included in this observer-blinded, intrapatient comparison trial. PUVA treatment was given four times weekly. Additionally, tacalcitol ointment and 0.1% tazarotene gel were applied separately on two target areas once daily in the evening. At the onset of therapy and every 2 weeks thereafter the response to treatment was determined by the Psoriasis Severity Index score, which assesses the degree of erythema, infiltration and scaling of the psoriatic lesions. After complete or near complete clearing patients were followed-up until relapse. Results Twenty-four patients completed the study. The treatment requirements to induce complete or near complete clearing were significantly lower for both combination treatments than for PUVA monotherapy (P<0.01). The median cumulative UVA dose and number of exposures were 30.6 J cm(-2) (95% confidence interval, CI 22.5-71.2) and 14 (95% CI 11-16) for tacalcitol plus PUVA, 32.3 J cm(-2) (95% CI 22.5-73.8) and 14 (95% CI 11-19) for tazarotene plus PUVA, and 37.0 J cm(-2) (95% CI 29.5-83.9) and 16 (95% CI 14-22) for PUVA monotherapy. No difference between the three regimens was observed with regard to duration of remission. Adverse reactions occurred more often with 0.1% tazarotene than with tacalcitol but were in general mild and completely reversible upon using a lower concentration of 0.05% tazarotene. Conclusions Tacalcitol ointment and tazarotene gel are both comparably effective in improving the therapeutic result of PUVA therapy in patients with chronic plaque-type psoriasis. Besides accelerating the treatment response, both agents, by virtue of their UVA dose-sparing effect, might also help to reduce possible long-term hazards of PUVA treatment.