ABSTRACT

Among the physical skin parameters, color certainly is the most important in clinical dermatology. The experienced dermatologist uses color information in several ways. In order to understand the measuring principles of the instruments, one should be aware of how colors are expressed as numerical values. Colors may be described by their hue (color position in the color wheel), their lightness, and their saturation. Color-measuring instruments have found wide application in skin bioengineering. While only few studies have been performed on the determination of color changes in clinical disease, the main application thus far has been quantification of erythema on various experimental situations, such as in the study of irritant dermatitis, and in the context of dermatopharmacological studies estimating topical corticoid activity in the vasoconstriction test, and measuring percutaneous penetration in the nicotinate model.