• calcitriol ointment;
  • plaque psoriasis;
  • randomized controlled trial;
  • ultraviolet B phototherapy

Background  Combinations of topical treatments and ultraviolet (UV) B phototherapy for plaque psoriasis may be more beneficial than either type of treatment used alone.

Objectives  To determine the efficacy of calcitriol 3 µg g−1 ointment in combination with UVB phototherapy in treating plaque psoriasis.

Methods  Calcitriol ointment with UVB was compared with vehicle plus UVB in a randomized, double-blind study in 104 patients.

Results  Mean global improvement scores for both groups increased over the 8-week study period; there was a statistically significant difference (P < 0·05) in favour of the calcitriol/UVB combination from week 1. At end-point, 45% of the calcitriol/UVB group showed considerable improvement or clearing of psoriasis, compared with 21% of the control group. The superiority of calcitriol plus UVB was also reflected in the global severity and Psoriasis Area and Severity Index (PASI) scores; at end-point the mean percentage decrease in PASI score was 65% for the calcitriol/UVB group and 43% for vehicle/UVB (P = 0·0014). The incidence of skin-related adverse events was low (< 12%) and similar in the two treatment groups. No clinically significant changes in blood chemistry, in particular calcium levels, occurred. The greater efficacy of combined calcitriol and phototherapy allowed a 34% decrease in total UVB exposure.

Conclusions  Calcitriol 3 µg g−1 ointment and UVB phototherapy in combination provides a promising therapy for managing chronic plaque psoriasis.