Assessment of Topical Corticosteroid-Induced Skin Blanching Response Using the Visual Mckenzie-Stoughton and Colorimetric Methods

Abstract

The use of a portable noninvasive colorimeter is evaluated in the present studies for its ability to objectively assess the skin blanching response in vivo. Its correlation and application in differentiating the influence of vehicle, potency, circadian activity, and dose response of topical corticosteroid treatment in healthy subjects among various skin types is consistently high (r > 0.8) using the “a” scale values, which represent reflected light from the skin in the green-red color spectrum (low-to-high values). The colorimeter is most useful in bioequivalence studies where differences in subject skin pigment or sun exposure exist between designated test skin sites in the same individual. The “a” scale of the colorimeter is reproducible and demonstrates a lower intrasubject variability than the visual assessment of the skin blanching response (SBR). The colorimeter data suggest that it will be very useful in the objective and noninvasive assessment of topical corticosteroid bioequivalence.