New approach to estimating TEWL developed

A group of researchers from Japan have developed a new model for the estimation of trans-epidermal water loss (TEWL) without the need for a tightly controlled environment.

In a paper published in Advanced Biomedical Engineering, the investigators demonstrate that a model using measures of stratum corneum thickness and the water content at the surface of the stratum corneum could accurately estimate TEWL.

In a press release from Okayama University, senior study author Takao Nakamura said: “Quantitative evaluation of skin barrier function is very useful in areas like dermatology, nursing, and cosmetics development. Our new model has the potential to make the measurement of skin barrier function easier.”

Nakamura is a professor at the Department of Radiological Technology, Graduate School of Health Sciences, at Okayama University in Japan, where he leads the Biomedical Engineering Laboratory.

To measure the thickness and water content of the stratum corneum, researchers used confocal laser microscopy and confocal Raman spectroscopy techniques. This imaging data can be used to calculate measurements related to water evaporation from the skin surface. Those measurements can then be fed into the mathematical model devised by the researchers to provide an estimate of the TEWL, ultimately indicating the protective ability of the skin.

The authors say the new model has several advantages over existing approaches. For instance, it can help identify the reasons for underlying changes in TEWL. “It may be possible to estimate whether the change in TEWL is a change in thickness of the stratum corneum or a change in water content of the surface of the stratum corneum,” said study author Osamu Uehara.

Another advantage is that since the model does not operate in an artificial environment, it provides a more realistic picture of water loss from the skin, according to the release.

Efficient ways to measure skin barrier function can support the development of skin care products and help consumers make more informed choices about the products they use.

“In daily skin care, people will be able to choose products that match their skin conditions, such as the thickness of the stratum corneum and the water content of the surface of the stratum corneum. In addition, they will have a better idea of the optimum amount of product to be used,” said lead author Dr. Toshimasa Kusuhara.