Characterization of facial skin of various Asian populations through visual and non-invasive instrumental evaluations: influence of seasons

Background/purpose This multicenter study assessed the impact of two types of extreme seasons (i.e. summer and winter) on the facial skin of female subjects living in different regions of Asia. Methods Facial skin of female subjects of various Asian ethnicities was characterized during summer and winter using dermatological assessments of the cheek and instrumental evaluations of the forehead and cheek. Approximately, 100 female subjects each from five cities in Asia (Harbin and Shanghai in China; New Delhi, India; Seoul, South Korea; and Sendai, Japan) ranging in age from 14 to 75 years were included in this study. Results Dermatologist assessments revealed a general decrease in severity of roughness, wrinkles, pigmentation, and lentigines during winter compared with summer. Instrumental assessments revealed significant differences in various parameters in winter vs. summer such as reductions in melanin index and skin surface hydration, and increases in transepidermal water loss, skin pH, redness, and sebum production. Conclusion Facial skin in female subjects living in different Asian cities exhibited a wide range of changes and worsening of various biophysical parameters in response to the low temperature and humidity during the winter season as compared with summer.