Tagami H
Tohoku University School of Medicine, Sendai, Japan.
Acta Derm Venereol Suppl (Stockh). 1994;185:29-33.
The superficial portion of the stratum corneum (SC), which is always under the influence of various exogenous factors, easily develops firm and brittle skin surface changes, whenever its hydration state is reduced or whenever there is any functionally deficient area of pathological SC that is unable to retain enough water even in the usual ambient conditions. In contrast, the deeper portion of the SC, which is always well hydrated because of its structural closeness to fully water-saturated viable epidermis, does not pose any serious problems as long as the skin is normal. Based on in vivo and in vitro measurements we have established that high-frequency conductance is a non-invasive technique which measures the hydration state of the superficial portion of the SC, the crucial part determining the physical properties of the skin surface.
角质层（SC）的表层始终受到各种外源性因素的影响，每当其水合状态降低时，或者每当存在病理性SC的功能缺陷区域，即使在通常的环境条件下也无法保留足够水分时，就容易出现皮肤表面变硬变脆的变化。相比之下，SC的深层由于其与完全水饱和的活表皮结构紧密而始终保持良好的水合状态，只要皮肤正常就不会出现任何严重问题。基于体内和体外测量，我们已经确定高频电导是一种非侵入性技术，可测量SC表层的水合状态，而这是决定皮肤表面物理性质的关键部分。
