Comparison of the effects of calcipotriol, prednicarbate and clobetasol 17-propionate on normal skin assessed by ultrasound measurement of skin thickness.

In this study, we investigated the effect of calcipotriol, prednicarbate and clobetasol 17-propionate on skin thickness over a treatment period of 6 weeks. The study was conducted as a controlled, randomized, double-blind comparison. The influence of these drugs on normal skin under occlusive conditions was assessed visually and by measuring skin thickness using 20 MHz B mode ultrasound. Both topically applied glucocorticosteroids lead to a significant decrease in skin thickness. In contrast to the glucocorticosteroid-induced atrophy, calcipotriol application on normal skin leads to an increase in skin thickness in all volunteers. The effect remains constant for the duration of treatment. The cause of this increase seems to be an irritative reaction of the skin which was histologically investigated in one volunteer. The histological features of this reaction are characteristic for a subacute dermatitis. The implications of these findings for the therapeutic mechanism of calcipotriol are discussed.