Mayrovitz Harvey N, Berthin Trixie
Medical Education, Nova Southeastern University Dr. Kiran C. Patel College of Allopathic Medicine, Fort Lauderdale, USA.
Osteopathic Medicine, Marian University College of Osteopathic Medicine, Indianapolis, USA.
Cureus. 2021 Sep 2;13(9):e17665. doi: 10.7759/cureus.17665. eCollection 2021 Sep.
A variety of skin measurements are routinely made in various clinical and research settings to evaluate the skin's biophysical properties for diagnostic and research purposes. Such measurements include transepidermal water loss (TEWL), skin pH, sebum, skin blood flow (SBF), and tissue dielectric constant (TDC) as a measure of skin water. Given the various reported circadian, diurnal, and possible ultradian and other temporal variations in skin physiological processes, it is of value to have clarity as to possible temporal variations in skin's biophysical properties associated with such processes. It was thus the purpose of this investigation to review and detail key elements of what is currently known regarding such variations and to provide a characterization that will permit informed judgments as to the sensitivity of the timing of measurements to optimize measurement reproducibility. Understanding these variations and their possible oscillatory effects on skin biophysical properties may aid physicians in providing optimal treatment timing for dermatological conditions and offer researchers insight into optimal measurement timing. The major findings of the present investigation that systematically searched multiple databases and critically examined pertinent findings, revealed that of the several skin parameters reviewed, which included TEWL, pH, sebum, SBF, TDC, and thickness, each had at least one study describing a statistically significant within-a-day temporal change. The magnitude of these changes varied and may be large enough to be seriously considered when assessing these parameters in clinical and research settings. However, inconsistencies in reported temporal variations suggest that further systematic research is well warranted especially with respect to temporal within-a-day and day-to-day variabilities of TEWL, TDC, and mechanical properties. At present, the impact of this type of confounding variability on reported values for skin biophysical parameters is unclear and worthy of further clarification.
在各种临床和研究环境中，通常会进行多种皮肤测量，以评估皮肤的生物物理特性，用于诊断和研究目的。此类测量包括经表皮水分流失（TEWL）、皮肤pH值、皮脂、皮肤血流量（SBF）以及作为皮肤水分度量的组织介电常数（TDC）。鉴于皮肤生理过程中存在各种已报道的昼夜节律、日变化以及可能的超日节律和其他时间变化，明确与这些过程相关的皮肤生物物理特性的可能时间变化具有重要意义。因此，本研究的目的是回顾和详细阐述目前已知的关于此类变化的关键要素，并提供一种特征描述，以便对测量时间的敏感性做出明智判断，从而优化测量的可重复性。了解这些变化及其对皮肤生物物理特性可能产生的振荡效应，可能有助于医生为皮肤病提供最佳治疗时机，并为研究人员提供关于最佳测量时机的见解。本研究系统地检索了多个数据库并严格审查了相关研究结果，主要发现表明，在所审查的几个皮肤参数中，包括TEWL、pH值、皮脂、SBF、TDC和厚度，每个参数都至少有一项研究描述了一天内具有统计学意义的时间变化。这些变化的幅度各不相同，在临床和研究环境中评估这些参数时，其幅度可能大到足以引起认真考虑。然而，所报道的时间变化存在不一致性，这表明有必要进行进一步的系统研究，特别是关于TEWL、TDC和机械性能的日内和日间时间变异性。目前，这种混杂变异性对皮肤生物物理参数报告值的影响尚不清楚，值得进一步阐明。
