The Winter Season Affects More Severely the Facial Skin than the Forearm Skin: Comparative Biophysical Studies Conducted in the Same Japanese Females in Later Summer and Winter

Abstract

Skin disorders such as atopic dermatitis, psoriasis and senile xerosis show a tendency to exacerbate in winter. We investigated the seasonal influence on the functional parameters of the skin in healthy female volunteers of different age groups. Biophysical noninvasive measurements, including transepidermal water loss (TEWL) as a parameter for the barrier function of the stratum corneum (SC), high-frequency conductance as a parameter for the hydration state of the SC, temperature, color and casual surface lipid levels, were conducted during the later summer and winter months in 39 healthy adult Japanese females ranging in age from 24 to 78 years. The measurements were made on the cheek, the exposed area, and flexor forearm, the semicovered area, in the same climate-controlled chamber. The barrier function of the SC was found to be significantly impaired in winter both on the cheek and flexor forearm. This difference between summer and winter was much larger on the cheek than on the forearm. The hydration state of the SC was significantly lower in winter on the flexor forearm, whereas no such seasonal change was apparent on the cheek where sebum levels did not show any seasonal change. We measured the corneocyte size in 24 out of the 39 subjects to estimate a seasonal change of the turnover rate of the SC. It tended to be smaller only on the exposed cheek skin, suggesting an enhanced turnover of the SC in winter, whereas it was somewhat larger on the semicovered flexor forearm. The skin surface temperature and redness were also significantly higher on the cheek in winter. We think that subclinical inflammation resulted in the enhanced turnover rate of the SC associated with elevated TEWL levels observed on the face in winter. In conclusion, the obtained data suggest that the exposed facial skin becomes more irritable under the influence of the dry and cold environment of winter even in healthy individuals where the barrier function of the SC is relatively poor as compared to the skin of other areas.

Dry skin conditions are related to the recovery rate of skin temperature after cold stress rather than to blood flow

“…The seasonal shift from summer to winter leads to an increase of TEWL and decreases the amount of water in the stratum corneum. 27,28 In our visual dryness rating of each subject's body and facial skin, most subjects showed no skin dryness or only a slight dryness in the summer (Table 5). However, the deterioration of skin dryness by the seasonal change to winter is considerably different between the high RR and the low RR groups.…”

Improvement of Mild Inflammatory Changes of the Facial Skin Induced by Winter Environment with Daily Applications of a Moisturizing Cream

“…In our previous study conducted in healthy individuals, we demonstrated that their skin barrier function on the face is impaired in winter, showing higher TEWL values, being accompanied by smaller sizes of the corneocytes obtained from the skin surface compared to those in summer, which reflects a quicker turnover rate of the epidermis probably due to irritation caused by the dry and cold winter environment [10]. In fact, low humidity itself was shown to stimulate the epidermal DNA synthesis, amplifying the hyperproliferative response of the epidermis to barrier disruption [12].…”

“…Evaluations of the properties of the SC of inflammatory dermatoses have greatly improved with recent advances in non-invasive biophysical methods as well as cytological analyses of cytokines in the SC [7, 8]and the differentiation end-products such as the cornified envelope (CE) [9], enabling us to detect changes that are unrecognizable clinically. By using biophysical measurements, we have recently found that the poorly protected facial skin showed unexpected deterioration in the functional properties of the SC in the dry and cold winter time when compared with those evaluated in the warm and humid summer time in the same individuals, probably reflecting subclinical underlying inflammation [10]. Thus, we conducted a half-side test on the face to determine how facial skin changes induced by a winter environment are improved by daily applications of a moisturizing cream as assessed by non-invasive biophysical and cytological methods.…”

The Predilection Sites for Chronic Atopic Dermatitis Do Not Show Any Special Functional Uniqueness of the Stratum corneum

“…It is of note that those collected from the lesional skin of the limbs were comparable or rather larger than those found on the cheek of the normal individuals. Because the facial skin is always exposed to various kinds of environmental stimuli, we can speculate that it is in a subclinical inflammatory state even in normal individuals [26].…”