Skin color measurements: comparison between three instruments: the Chromameter (R), the DermaSpectrometer (R) and the Mexameter (R)

Background/aims: Two types of skin reflectance instruments are available no wadays for the determination of skin color: a tristumulus colorimeter (Chro mameter from Minolta) using the CIE L*a*b* color system and the narrow-band simple reflectance meters (DermaSpectrometer from Cortex and Mexameter fro m Courage-Khazaka) using the erythema/melanin indices. The purpose of this study was to compare the capabilities of the three instruments (sensitivity , repeatability and correlation) in vitro and in vivo. Methods: Comparative color measurements were carried out first in vitro on standardized color charts and subsequently in vivo on different skin areas in human volunteers. Skin color changes induced by various physico-chemical treatments were also quantitatively evaluated with the three instruments. Results: The in vitro and in vivo repeatabilty as well as the sensitivity o f the three instruments are rather good. Erythema and skin blanching could be readily quantified by the increase of the a* parameter and of the erythe ma indices of the simple reflectance meters. Natural UV tanning and artific ial chemical tanning could be measured by the decrease of L* and increase o f b* and of the melanin indices. Conclusion: The Chromameter and the two narrow-band reflectance instruments were able to characterize skin color and to quantify small skin color chan ges. Moderate to high significant linear correlations could be established between the CIE L*a*b* color parameters and the erythema/melanin indices.