Department of Dermatology, School of Medicine, University of California, San Francisco, CA, USA.
Skin Res Technol. 2009 Nov;15(4):392-8. doi: 10.1111/j.1600-0846.2009.00376.x.
BACKGROUND/AIMS: Two main systems have been utilized for measuring transepidermal water loss (TEWL): open chamber and closed chamber. Yet, further validation and standardization studies may be necessary to reveal the sensitivity, precision, and robustness of these instruments.
Three instruments are compared for their applicability to assess TEWL: unventilated chamber, open chamber and condenser chamber. The comparative study was performed on human forearm skin (n=6), in the normal condition (baseline), and after (1) 10 tape strippings on both arms, (2) moisturizer cream (Eucerin) and petrolatum application for 1 h, and (3) 1% sodium lauryl sulfate (SLS) aqueous solution and distilled water (as control) application for 20 min.
The condenser-chamber system, was the only device among these three that could show the effect of tape stripping on TEWL values as compared with baseline (P<0.001). The effect of moisturization, in terms of % change of TEWL values after application of cream and petrolatum, did not show significant difference between devices (P>0.05). However, only the values obtained from condenser-chamber device revealed a highly significant change as compared with baseline (P<0.001). Condenser-chamber system could also discriminate between the effect of moisturizer and petrolatum on TEWL values (P<0.05). The change of TEWL values after SLS application was shown to be significant by unventilated and condenser-chamber systems (P<0.05). However, none of the devices differentiated between the effect of water and 1% SLS solution applied for 20 min. The values obtained from all three instruments correlate well with each other (P<0.001).
Our results highlight the differences between two closed-chamber TEWL measurement instruments, which are designed based on different measurement principles. This may provide insights to find the best practice to improve the quality, precision and sensitivity of the measurements.
背景/目的：有两种主要的系统被用于测量经皮水分丢失（TEWL）：开放式腔室和封闭式腔室。然而，可能需要进一步的验证和标准化研究来揭示这些仪器的灵敏度、精度和稳健性。
比较了三种仪器在评估 TEWL 方面的适用性：无通风腔室、开放式腔室和冷凝器腔室。在正常状态（基线）下，对人体前臂皮肤（n=6）进行了比较研究，然后进行了以下操作：（1）双臂各进行 10 次胶带剥离；（2）应用 Eucerin 保湿霜和凡士林 1 小时；（3）应用 1%十二烷基硫酸钠（SLS）水溶液和蒸馏水（作为对照）20 分钟。
这三种仪器中，只有冷凝器腔室系统能够显示胶带剥离对 TEWL 值的影响，与基线相比差异有统计学意义（P<0.001）。应用乳膏和凡士林后 TEWL 值的变化，以%表示，在设备之间没有显著差异（P>0.05）。然而，只有冷凝器腔室设备获得的结果与基线相比有显著变化（P<0.001）。冷凝器腔室系统还可以区分保湿霜和凡士林对 TEWL 值的影响（P<0.05）。应用 SLS 后 TEWL 值的变化在无通风腔室和冷凝器腔室系统中均显示出显著差异（P<0.05）。然而，没有一个设备可以区分 20 分钟应用水和 1% SLS 溶液的效果。三种仪器获得的结果彼此相关性良好（P<0.001）。
我们的结果强调了两种基于不同测量原理设计的封闭式 TEWL 测量仪器之间的差异。这可能为找到提高测量质量、精度和灵敏度的最佳实践提供一些见解。
