Skin color of Chinese women across different regions of China:An analysis based on both individual typology angle and hue angle

Skin color is considered an important beauty standard for women in China.The typical tool for skin color measurement,individual typology angle(ITA),was developed based on Caucasian skin features.The ITA effectively measures the brightness of facial skin,which is traditionally associated with beauty in Caucasian women.However,in Chinese women,whiteness is not the only determinant of skin esthetics,and other elements such as“yellowness”and“redness”are also important considerations.Thus,the hue angle system was developed based on the skin features of Chinese women,whose skin is typically on the“yellow-red”spectrum.Studies examining the skin color of Chinese women based on both the ITA and hue angle should be carried out.The skin colors of 4500 women aged 18–45 years across five different regions of China were measured using both the ITA and hue angle systems.The relationship of the“red pigment and melanin content”with the“brightness and redness of skin color”was also examined.Further,the different skin types of women across different regions were identified.Measurements based on the ITA system reveal a saddle-shaped distribution of skin brightness among Chinese women across five different regions,with skin brightness being high in the eastwest regions and low in the north-south regions.The ITA and hab values are not consistent in individual women,and thus,both need to be considered when evaluating skin color.Additionally,no correlation between the skin’s red pigment and melanin content and the skin’s ITA and hab values is identified.This study provides skin color data based on both the ITA and hue angle systems.The findings show that skin ITA/hab values cannot simply be explained by the red pigment/melanin content of the skin.Given the distribution of skin types across different regions of China,whitening ingredients causing little to no irritation should be used to formulate whitening cosmetics.

A Method of Evaluation Efficacy of Cosmetics Exfoliator and Its Application

Measuring the tanning skin can provide a scientific method to evaluate the efficacy of cosmetics exfoliator.Dihydroxyacetone(DHA,5.0%(w/w))was used to stain the inner forearms cuticle of subjects.The skin surface L*and b*were determined,then ITA and its recovery rate were calculated to evaluate the exfoliating efficacy of cosmetics.The results showed that no significant(P≥0.05)differences were observed for L*,b*and ITA on different skin surface of unstained subjects.After staining with DHA,no adverse reaction was found in the stained areas,and the changes of L*,b*and ITA on different skin surface were consistent(P≥0.05).Two different cosmetics were used continuously to exfoliate the skin in different areas.After treatment for 7 days,the corresponding areas of skin L*,b*and ITA had significant(P<0.05)improvement in comparison with negative control area.But there were differences in the evaluation results of the exfoliation efficacy using these three parameters.The recovery rate of ITA of two samples improved significantly(P<0.05)than the negative control area.The work indicated that using 5.0%DHA for skin browning and measuring the skin surface color change by ITA recovery rate can accurately and sensitively assess the skin cuticle renewal rate difference.This method can be used as one of the effective way to evaluate the efficacy of cosmetics exfoliation.