Egawa Mariko, Oguri Motoki, Kuwahara Tomohiro, Takahashi Motoji
Shiseido Research Center (SHIN-YOKOHAMA), 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama 224-8558, Japan.
Skin Res Technol. 2002 Nov;8(4):212-8. doi: 10.1034/j.1600-0846.2002.00351.x.
BACKGROUND/AIMS: Changes in the skin conditions after exposure to low humidity have been generally experienced in everyday life, but there have been few reports to approach it-especially in healthy skin. We have examined the effect of low humidity on healthy human skin by using noninvasive measurement devices.
Skin conditions on the ventral forearm and the cheek before and after 3 or 6 h exposure to low humidity were evaluated by measuring skin surface conductance, skin surface capacitance and transepidermal water loss. Skin surface replicas were also taken before and after exposure and analysed for roughness parameters--Ra (arithmetic mean roughness value), Rz (10-point height), Sm (mean value of the profile element) and VC1 (anisotropy of skin furrows).
There was a significant decrease of water content of stratum corneum at both test sites from the time points 0 h to 3 h and 6 h (P < 0.01) and transepidermal water loss from the time point 0 h to 6 h (P < 0.05). Regarding the roughness parameters, a significant increase of Rz in the directions of 45 degrees/225 degrees and 90 degrees/270 degrees to the body axis and Sm in the directions of 0 degrees/180 degrees (P < 0.05) on the forearm and VC1 (P < 0.05) on the cheek. The parameter Rz also showed a tendency to increase in the directions of 45 degrees/225 degrees (P = 0.06) on the cheek. A specific pattern of the changes to be related to the Langer's lines in the surface morphology was observed. The changes of skin surface pattern in our experiment lead us to consider that exposure to low humidity even in such a short period would be related to inducing aggravation of skin texture and the formation of fine wrinkles.
A short exposure of skin to a low-humidity environment induced changes in the moisture contents in the stratum corneum and skin surface pattern, which lead us to assume that a dry environment in our daily life would make fine wrinkles related to lack of water in the stratum corneum.
背景/目的：在日常生活中，人们普遍会经历暴露于低湿度环境后皮肤状况的变化，但相关研究报道较少，尤其是针对健康皮肤的研究。我们使用非侵入性测量设备研究了低湿度对健康人体皮肤的影响。
通过测量皮肤表面电导、皮肤表面电容和经表皮水分流失，评估前臂腹侧和脸颊在暴露于低湿度环境3或6小时前后的皮肤状况。在暴露前后还制作了皮肤表面复制品，并分析粗糙度参数——Ra（算术平均粗糙度值）、Rz（十点高度）、Sm（轮廓元素平均值）和VC1（皮肤皱纹各向异性）。
从0小时到3小时和6小时，两个测试部位的角质层含水量均显著下降（P<0.01），从0小时到6小时经表皮水分流失显著增加（P<0.05）。关于粗糙度参数，在前臂上，与身体轴线成45度/225度和90度/270度方向的Rz以及与身体轴线成0度/180度方向的Sm显著增加（P<0.05），脸颊上的VC1显著增加（P<0.05）。脸颊上与身体轴线成45度/225度方向的Rz也有增加趋势（P=0.06）。观察到表面形态变化与朗格线相关的特定模式。我们实验中皮肤表面模式的变化使我们认为，即使在如此短的时间内暴露于低湿度环境也可能与皮肤纹理恶化和细纹形成有关。
皮肤短时间暴露于低湿度环境会导致角质层水分含量和皮肤表面模式发生变化，这使我们推测日常生活中的干燥环境会导致与角质层缺水相关的细纹产生。
