Int J Cosmet Sci. 1999 Aug;21(4):241-52. doi: 10.1046/j.1467-2494.1999.196570.x.
The purpose of this in vivo study was to investigate, non-invasively on human subjects, xerotic skin and its physiological evolution over time, compared to normal skin. Two groups of 17 female subjects were studied during the winter season, one made up of subjects with normal skin and the other subjects with xerotic skin. A clinical assessment and biometrological measurements of hydration and transepidermal water loss (TEWL) were performed on the same area of the external antero-lateral surface of the leg at the start of the study then after three weeks. At the end of the study, the ultrastructure of stratum corneum samples taken from the same area was examined by transmission electron microscopy. Subjects with xerotic skin were selected according to their impaired cutaneous barrier function, reflected in a TEWL higher than 12 g/m ; 2/h. Compared to normal subjects, they presented a hydration level more than 25% lower. After an interval of 21 days, no significant change in the hydration level or clinical appearance of the xerotic skin was observed. In contrast, the TEWL had decreased significantly (D _ 21- D _ 0=-3.6 g/m ; 2/h; p < 0.001) but still stayed higher than normal values. Changes in the ultrastructure of the stratum corneum were also observed in the subjects with xerotic skin. Unlike normal skin, corneosomes could be detected right up to the surface layers, accompanied by intercellular lipids in an amorphous form. These observations confirm the important roles played by both corneosomes and lipid organization in the cohesion/desquamation processes. In the subjects with normal skin, the hydration level and barrier function remained unchanged during the three week study but an onset of skin dryness was observed, the mean clinical score increasing by +1.3 (p = 0.01). These results confirm that there is no direct relationship between TEWL and the severity of skin dryness. It appears that a clinical evaluation is more sensitive than biometrological measurement for describing early state of cutaneous dryness. This study highlights the importance of a regular cosmetic or dermopharmaceutical treatment during the winter to prevent xerosis apparition on legs.
本体内研究的目的在于，在人体对象上非侵入性地，对干燥皮肤及其随时间推移的生理演变，与正常皮肤进行比较。在冬季，将两组各 17 名女性对象纳入研究，一组由正常皮肤对象组成，另一组由干燥皮肤对象组成。在研究开始时，然后在 3 周后，对小腿外部前外侧表面的同一区域进行临床评估和水合及经表皮水分流失（TEWL）的生物计量测量。在研究结束时，通过透射电子显微镜检查取自同一区域的角质层样本的超微结构。选择干燥皮肤对象是根据其受损的皮肤屏障功能，表现在 TEWL 高于 12 g/m ；2/h。与正常对象相比，它们的水合水平低 25%以上。经过 21 天的间隔，干燥皮肤的水合水平或临床外观没有观察到明显变化。相比之下，TEWL 显著下降（D _ 21- D _ 0=-3.6 g/m ；2/h；p < 0.001），但仍高于正常水平。干燥皮肤对象的角质层超微结构也发生了变化。与正常皮肤不同，角质小体可以一直检测到表面层，同时伴有无定形的细胞间脂质。这些观察结果证实了角质小体和脂质组织在粘附和脱屑过程中所起的重要作用。在正常皮肤的对象中，水合水平和屏障功能在 3 周的研究期间保持不变，但观察到皮肤干燥的开始，平均临床评分增加+1.3（p = 0.01）。这些结果证实 TEWL 与皮肤干燥的严重程度之间没有直接关系。似乎临床评估比生物计量测量更能敏感地描述皮肤干燥的早期状态。本研究强调了在冬季定期使用化妆品或皮肤药进行治疗的重要性，以防止腿部出现干燥。
