Evaluation of topical antipsoriatic treatment by chromametry, visiometry and 20-MHz ultrasound in the psoriasis plaque test.

The antipsoriatic effects of two topical antipsoriatic agents, betamethasone valerate (Betnovate) and calcipotriol (Daivonex), and a pure nanocolloid gel were assessed in 10 patients with chronic plaque-type psoriasis in a modified psoriasis plaque test. Three noninvasive bioengineering methods were applied to measure antipsoriatic effects: chromametry for objective evaluation of erythema; visiometry, a method for profilometry, and 20-MHz skin ultrasound for the measurement of skin thickness as a parameter of inflammatory infiltration and psoriatic hyperproliferation of the epidermis. Regarding inflammation parameters such as skin thickness (infiltration) and erythema (dilatation of vessels and hyperperfusion), the steroid preparation Betnovate proved to be significantly most effective in our study. Daivonex showed significant decreases in the skin roughness parameters, underlining its antiproliferative effect. The nanocolloid carrier was significantly effective in thickness reduction, this effect being most probably due to occlusion. 20-MHz ultrasound, chromametry and visiometry proved to provide multiparameter assessment of treated and untreated psoriatic skin and can be recommended as objective and reproducible measurements for further studies.