Lodén M
Department of Dermatology, University Hospital, Uppsala, Sweden.
Acta Derm Venereol Suppl (Stockh). 1995;192:1-48. doi: 10.2340/00015555192148.
During recent years several highly developed non-invasive methods for evaluation of skin physiology and pathology have been introduced. Against this background, the present studies were undertaken with the primary aim of assessing the effects of various skin care products on some properties of the skin. Skin topography was measured by profilometry on skin replicas, friction with a newly developed friction instrument, capacitance with a Corneometer, and barrier function both with an Evaporimeter to assess transepidermal water loss (TEWL) and by application of an irritant followed by measurement of the resulting irritative reaction. Initially some of the techniques were used to further characterize the differences between dry atopic skin and normal skin. Dry skin exhibits increased values of roughness parameters and a reduced number of topographical peaks. TEWL is increased, indicating impaired barrier function. The friction and capacitance are lower and correlate significantly to each other, whereas TEWL does not appear to relate to either of these parameters. The use of a scrub cream removes the outermost part of the stratum corneum, resulting in a smoother skin. Application of moisturizers modifies the frictional response of the skin. The friction instrument gave results comparable to those of panelists trained in sensory evaluation. The study suggests that measurement of skin friction can be used to predict the degree of liking of moisturizers. Furthermore, moisturizers increase the skin hydration. They provide water directly to the skin from their water phase. Skin hydration also increases with increased degree of occlusion, as measured as a decrease in TEWL. Moisturizers may also alter the diffusional resistance of the stratum corneum and reduce the skin susceptibility to the surfactant sodium lauryl sulphate (SLS). Lipids in moisturizers may influence already developed SLS-induced irritation. A significantly lower degree of irritation was found in areas treated with canola oil and its sterol-enriched fraction than in an area treated with water. These findings emphasize that skin care products do not only form an inert, epicutaneous layer, but that they may penetrate and influence the structure and function of the skin.
近年来，已引入了几种高度发达的用于评估皮肤生理和病理的非侵入性方法。在此背景下，开展了本研究，其主要目的是评估各种护肤品对皮肤某些特性的影响。通过对皮肤复制品进行轮廓测定法来测量皮肤表面形貌，使用新开发的摩擦仪器测量摩擦力，使用角质层水合测量仪测量电容，通过使用蒸发仪评估经表皮水分流失（TEWL）以及施加刺激物后测量产生的刺激反应来评估屏障功能。最初，其中一些技术被用于进一步表征干性特应性皮肤和正常皮肤之间的差异。干性皮肤的粗糙度参数值增加，表面形貌峰数量减少。TEWL增加，表明屏障功能受损。摩擦力和电容较低且彼此显著相关，而TEWL似乎与这些参数中的任何一个均无关联。使用磨砂膏可去除角质层的最外层，使皮肤更光滑。涂抹保湿剂可改变皮肤的摩擦反应。该摩擦仪器给出的结果与经过感官评估培训的小组成员的结果相当。该研究表明，测量皮肤摩擦力可用于预测对保湿剂的喜好程度。此外，保湿剂可增加皮肤水分含量。它们从水相中直接为皮肤提供水分。随着闭塞程度增加，皮肤水分含量也会增加，这可通过TEWL降低来衡量。保湿剂还可能改变角质层的扩散阻力，并降低皮肤对表面活性剂月桂醇硫酸酯钠（SLS）的敏感性。保湿剂中的脂质可能会影响已产生的SLS诱导的刺激。与用水处理的区域相比，在用菜籽油及其富含甾醇的馏分处理的区域中发现的刺激程度明显较低。这些发现强调，护肤品不仅会形成一层惰性的表皮层，而且它们可能会渗透并影响皮肤的结构和功能。
