Randomized double blinded placebo controlled comparative study of topical steroid plus bath PUVA versus bath PUVA and placebo cream

Background The trend in psoriasis therapy in recent years has been to combine different agents in the hope that the combination will deliver better results. Topical corticosteroids are frequently used along with PUVA (Psoralen+ ultraviolet A) therapy in the treatment of psoriasis. But there is no consensus whether they enhance the therapeutic response of phototherapy. Our aim was to assess the effect of topical corticosteroids in combination with bath PUVA therapy on psoriasis with respect to time of clearance & duration of remission. Methods It was a double blind randomized placebo controlled study. Twenty patients were divided into two groups by block randomization. One group was treated with bath PUVA and betamethasone propionate cream in (30/70) dilution cream while the other group was treated with PUVA and placebo cream. Bath PUVA was given for 15 treatments or until 90% clearance of disease whichever is earlier.The assessment was done by PASI_TUL scoring at the baseline, 3^rd, 6^th, 9^th, 12^th and 15^th sittings. Results Complete remission was achieved in all patients of steroid group and 8 patients of placebo group. The mean baseline PASITUL score decreased from 19.7 to 0.4 in steroid group and from 23.9 to 1.5 in placebo group. The mean cumulative UVA dose used in steroid and placebo groups were 32.85 Joules/cm2 and 40.60 Joules/cm2 respectively. The median number of UVA exposures used for >90% clearance in steroid group was 11 and for placebo group was 14 (p=.035). Out of 10 patients of steroid group 7 patients relapsed within six months while only 1 out of 8 patients who cleared completely in placebo group relapsed before 6 months (P=.023). Conclusion While there was tendency of early clearance in steroid group, there was no statistically significant difference in overall clearance and mean cumulative dose of UVA used. There were early relapses in steroid group which was statistically significant.