Muizzuddin N, Marenus K D, Maes D H
Estée Lauder Companies, Melville, NY 11747, USA.
Am J Contact Dermat. 1998 Sep;9(3):170-5.
Users of cosmetics and skin care products often report adverse reactions ranging from itching and dryness to intense inflammatory responses such as erythema or wheal and rash. Self-assessment is not always an accurate parameter for categorizing skin as sensitive or nonsensitive, although it can be valuable. For this reason, it is important to define sensitive skin by more objective factors.
Studies were undertaken to determine if objective biophysical measurements could detect differences in barrier function between those individuals who identified themselves as having sensitive skin and those self-identified as having normal skin. In addition, the effects of treatment on barrier functions of individuals with sensitive skin were determined.
Three main factors that contribute to cutaneous reactivities were observed for the estimation of skin sensitivity: barrier functions, reactivity to irritants, and neuronal responses manifested as sensory reactions. Barrier functions of the skin was tested by gentle removal of the stratum corneum with simple cellophane tape stripping followed by measurement of transepidermal water loss (TEWL) as a marker of barrier loss. The onset and intensity of skin reaction against an irritant, balsam of Peru, was tested on the same individuals to observe the reactivity of their skin. Using the lactic acid sting test, additional information regarding skin sensitivities was obtained.
Sensitive skin individuals exhibiting easy barrier damage possess delicate skin that is also highly reactive to irritants. When these individuals used a regimen of products that contained minimal preservatives and no surfactants for 8 weeks, the skin barrier and reactivity changed such that it was similar to nonsensitive skin.
Skin sensitivity is observed because of a combination of factors, including a disrupted barrier and a tendency to hyperreact to topical agents. Treatment with special topical skin care formulations can reduce overall skin sensitivity.
化妆品和护肤品使用者经常报告各种不良反应，从瘙痒、干燥到强烈的炎症反应，如红斑、风团和皮疹。自我评估虽然有价值，但并不总是将皮肤分类为敏感或非敏感的准确参数。因此，通过更客观的因素来定义敏感皮肤很重要。
进行研究以确定客观的生物物理测量是否能检测出自我认定为敏感皮肤的个体与自我认定为正常皮肤的个体之间屏障功能的差异。此外，还确定了治疗对敏感皮肤个体屏障功能的影响。
观察了导致皮肤反应性的三个主要因素以评估皮肤敏感性：屏障功能、对刺激物的反应性以及表现为感觉反应的神经反应。通过用简单的玻璃纸胶带轻轻去除角质层，然后测量经表皮水分流失（TEWL）作为屏障丧失的标志物，来测试皮肤的屏障功能。在同一批个体上测试对刺激物秘鲁香脂的皮肤反应的起始和强度，以观察其皮肤的反应性。使用乳酸刺痛试验，获得了有关皮肤敏感性的更多信息。
表现出容易出现屏障损伤的敏感皮肤个体拥有娇嫩的皮肤，对刺激物也高度敏感。当这些个体使用含最少防腐剂且无表面活性剂的产品方案8周后，皮肤屏障和反应性发生了变化，变得与非敏感皮肤相似。
观察到皮肤敏感是多种因素共同作用的结果，包括屏障破坏和对局部用药过度反应的倾向。使用特殊的局部皮肤护理配方进行治疗可以降低整体皮肤敏感性。
