Seasonal variations of epidermal biophysical properties in Kunming, China: A self‐controlled cohort study

Abstract

The skin is the largest organ of the human body, covering an area of approximately 2 m 2 in adult. The skin functions as multiple barriers, such as permeability barrier, microbial barrier, and immune barrier, protecting the skin against various insults. Among these barriers, epidermal permeability barrier prevents substances in and out the body through the skin, while melanin serves as epidermal pigment barrier, protecting the skin from excessive ultraviolet (UV) radiation. 1 Recent studies demonstrated that epidermal permeability barrier and pigment barrier co-regulated each other. Disruption of permeability

Seasonal variations in the skin parameters of Caucasian women from Central Europe

“…Winter is usually associated with lower sebum content in comparison with summer 19,21,23‐25,28,30,87 as we also observed in our study on the forehead. Several studies observed different results probably due to the overall lower sebum levels of the subjects (usually lower than 60 µg.cm ‐2 ) where the changes were not so prominent 16,18‐20,23,30,31 . Similar results were observed in our study on the cheek where the trend of higher sebum content in summer and spring was visible as well but was not statistically significant.…”

“…1). The vast majority of the studies found decreased SC hydration in winter as we also confirmed 11‐32 . Only a few studies observed no or opposite trends in some specific cases 13,16‐18,33 …”

“…Although the variability of the results from the studies was high, more studies found rather higher TEWL values in winter in comparison with summer 11,12,16‐21,28‐30,32,60 . However, no significant changes in TEWL between these two seasons have often been observed as well including our results 13,16,17,21,25,30,31,33 and there have been even a few studies where TEWL values in winter were found lower than in summer 13,20 . (p201), 25,32 …”

“…Spring and autumn have been involved in the studies less frequently, and the data were largely inconsistent with no common trends 21,23,28,30,31,87,91 . These results suggest again that these seasons are rather intermediate, and the production of sebum depends more on the specific environmental conditions during the studies.…”

<p>The Interaction of Age and Anatomical Region Influenced Skin Biophysical Characteristics of Chinese Women</p>

“…3 Many studies have reported that these skin biophysical parameters changed according to age, gender, anatomical regions and seasons in different ethnic populations. [4][5][6][7][8][9][10][11] Man et al demonstrated that the skin surface pH, sebum content and SC hydration varied with age, gender and body site in a large Chinese population. 12 Mayes et al reported that the facial skin L*a*b* skin colors, hydration and TEWL had associations with chronological age in Chinese females.…”