P05
Quantification of erythema using digital camera image analysis

In general, Irritant skin reactions are graded by using visual scoring method for the degree of erythema, edema and scaling. The main disadvantage of this method lacks objectivity and parametric properties. The purpose of this study is to develop a quantitative evaluation method by using computerized color image analysis of skin erythema. We have described the objective measurement of the irritant skin responses by using skin surface color determination and compared it with the measurement by using traditional visual scoring method. Using R (Red), G (Green), B (Blue) value and CIE color parameters (L*a*b*) of digital camera image by using the software program, two kind of erythema index (ΔRG, Δab) and change in total color (ΔE*ab) were calculated. ΔRG value and Δab in digital camera image were highly correlated with the degree of erythema than chromameter measurements. And Δab (difference in color redness (a*) and yellow hue (b*)) with the exception of luminance (L* value) in CIE was well correlated than change in total color (ΔE*ab). Our data showed that erythema indices (ΔRG, Δab) were good parameters for evaluation of skin erythema produced by irritant reaction.