Comparison of effectiveness and safety of excimer lamp vs topical calcipotriol-clobetasol propionate combination in the treatment of palmoplantar psoriasis.

Background: Very few studies have assessed the efficacy of excimer in the treatment of palmoplantar psoriasis (PPP), and none has compared the excimer with calcipotriol-clobetasol propionate combination.

Purpose: To compare the effectiveness and safety of excimer lamp vs topical ointment containing calcipotriol (0.005% w/w) and clobetasol propionate (0.05% w/w) combination in PPP.

Methods: This right-left randomization trial included 36 patients with PPP, who received treatment with excimer lamp (twice weekly) on one side and calcipotriol-clobetasol combination (once daily) on another side for 12 weeks, followed by 8 weeks of follow-up. Recruitment and response assessment was done by 2 experienced dermatologists (SD and TN) using modified palmoplantar pustular psoriasis area and severity index score (mPPPASI, originally devised for palmoplantar pustulosis, suitably modified to assess response in PPP). Primary outcome measure was percentage improvement in mPPPASI at 12 weeks, which was classified as minimal (≤25%), mild (>25%-50%), moderate (>50%-75%), and marked (>75%). Secondary outcome measures were the proportion of patients achieving >75% reduction in mPPPASI and the time taken to achieve it.

Results: Of 36 recruited patients, 33 completed treatment and 21 adhered to 8-weeks follow-up. The mean mPPPASI on the excimer-treated sides reduced significantly from 7.75 ± 4.62 to 4.01 ± 4.07 (P < .001) at 12th week (end of the treatment) and 2.66 ± 3.97 at 20th week (at 8 weeks follow-up). The mean mPPPASI on the calcipotriol-clobetasol combination treated sides reduced significantly from 7.36 ± 4.46 to 3.55 ± 3.77 (P < .001) and 2.70 ± 3.97 at 12th week and 20th week, respectively. The reduction was significant for both treatment and the difference between the two was not statistically significant. Minimal, mild, moderate, and marked improvement was seen in 5/33 (15.2%) and 1/33 (3.0%), 6/33 (18.2%) and 8/33 (24.2%), 12/33 (36.4%) and 13/33 (39.4%), and 8/33 (24.2%) and 8/33 (24.2%) sides in the excimer and calcipotriol-clobetasol combination, respectively. A total of 8 patients in each group achieved mPPPASI 75 at 12 weeks. The mPPPASI 75 was achieved at 2, 4, and 8 weeks in 1, 2, and 8 patients, respectively, using either modalities. The adverse effects (most commonly hyperpigmentation) were noted more frequently on the excimer-treated sides; however, they were well tolerated.

Conclusion: Both excimer lamp and calcipotriol-clobetasol propionate combination are equally effective in the treatment of PPP.