Characterization of Chinese body skin through in vivo instrument assessments, visual evaluations, and questionnaire: influences of body area, inter‐generation, season, sex, and skin care habits

Abstract
The varying influence of multiple factors (e.g., aging, sex, season, skin care habits) on skin structure and function necessitates study within ethnic groups to fully characterize their skin. Men and women aged 40-50 years (n = 43) and their consanguineous same-sex children, aged 18-25 years (n = 43), living in Chengdu, China were enrolled in this single center, non-interventional study. Volunteers attended two study visits (summer, 2010 and winter, 2011) at which dermatologists measured transepidermal water loss (TEWL), skin hydration, sebum secretion, fine lines/roughness, melanin/erythema, temperature, and color, and clinically graded participants' skin. Participants answered a questionnaire, indicating their perceived skin type/condition. Data were analyzed using t-test/anova or Friedman/Wilcoxon test. Objective measurements demonstrated statistically significant inter-generational differences in skin condition, with aged skin more wrinkled at most sites, having reduced oil/colder facial and décolletage skin, darker/more erythematous skin in exposed areas, and less hydrated/rougher heel skin; similarities were detected in skin melanin, erythema, and TEWL. There were also statistically significant differences between seasons and sexes. The intersection between instrument measurements and subjective perceptions of skin revealed notable differences. Objective measurements and their intersection with subjective perceptions demonstrate the influences of inter-generation, season, sex, and living habits on Chinese body skin.