Goad N, Gawkrodger D J
Skin Health Alliance, London, United Kingdom.
Department of Oncology and Metabolism, University of Sheffield Medical School, Sheffield, United Kingdom.
J Eur Acad Dermatol Venereol. 2016 Aug;30(8):1285-94. doi: 10.1111/jdv.13707. Epub 2016 Jun 15.
Humidity, along with other climatic factors such as temperature and ultraviolet radiation, can have an important impact on the skin. Limited data suggest that external humidity influences the water content of the stratum corneum. An online literature search was conducted through Pub-Med using combinations of the following keywords: skin, skin disease, humidity, dermatoses, dermatitis, eczema, and mist. Publications included in this review were limited to (i) studies in humans or animals, (ii) publications showing relevance to the field of dermatology, (iii) studies published in English and (iv) publications discussing humidity as an independent influence on skin function. Studies examining environmental factors as composite influences on skin health are only included where the impact of humidity on the skin is also explored in isolation of other environmental factors. A formal systematic review was not feasible for this topic due to the heterogeneity of the available research. Epidemiological studies indicated an increase in eczema with low internal (indoors) humidity and an increase in eczema with external high humidity. Other studies suggest that symptoms of dry skin appear with low humidity internal air-conditioned environments. Murine studies determined that low humidity caused a number of changes in the skin, including the impairment of the desquamation process. Studies in humans demonstrated a reduction in transepidermal water loss (TEWL) (a measure of the integrity of the skin's barrier function) with low humidity, alterations in the water content in the stratum corneum, decreased skin elasticity and increased roughness. Intervention with a humidifying mist increased the water content of the stratum corneum. Conversely, there is some evidence that low humidity conditions can actually improve the barrier function of the skin. Ambient relative humidity has an impact on a range of parameters involved in skin health but the literature is inconclusive. Further studies are needed to better delineate the interactions that can occur in normal and diseased states. Therapeutic measures might be forthcoming especially for skin diseases such as eczema, which are regarded as being characterized by 'skin dryness'. Further research examining the interaction between different environmental exposures thought to impact the skin, and indeed the interplay between genetic, environmental and immunological influences, are required.
湿度与温度、紫外线辐射等其他气候因素一样，会对皮肤产生重要影响。有限的数据表明，外部湿度会影响角质层的含水量。通过PubMed进行了在线文献检索，使用了以下关键词组合：皮肤、皮肤病、湿度、皮肤疾病、皮炎、湿疹和喷雾。本综述纳入的出版物限于：（i）人类或动物研究；（ii）与皮肤病学领域相关的出版物；（iii）以英文发表的研究；（iv）讨论湿度对皮肤功能的独立影响的出版物。仅在单独探讨湿度对皮肤的影响而不考虑其他环境因素的情况下，才纳入将环境因素作为对皮肤健康的综合影响进行研究的文献。由于现有研究的异质性，对该主题进行正式的系统综述不可行。流行病学研究表明，室内湿度低时湿疹增加，外部湿度高时湿疹也增加。其他研究表明，在内部空气调节环境湿度低时会出现皮肤干燥症状。小鼠研究确定，低湿度会导致皮肤发生多种变化，包括脱屑过程受损。人体研究表明，低湿度会使经表皮水分流失（TEWL，一种衡量皮肤屏障功能完整性的指标）减少，并使角质层含水量发生变化，皮肤弹性降低且粗糙度增加。使用加湿喷雾进行干预可增加角质层的含水量。相反，有证据表明低湿度条件实际上可以改善皮肤的屏障功能。环境相对湿度会对一系列与皮肤健康相关的参数产生影响，但文献尚无定论。需要进一步研究以更好地描述在正常和患病状态下可能发生的相互作用。特别是对于被认为以“皮肤干燥”为特征的湿疹等皮肤病，可能会有相应的治疗措施。需要进一步研究不同环境暴露之间被认为会影响皮肤的相互作用，以及基因、环境和免疫影响之间的相互作用。
