Side-by-side comparison of an open-chamber (TM 300) and a closed-chamber (Vapometer™) transepidermal water loss meter

The measurement of transepidermal water loss (TEWL) is used to monitor changes in the stratum corneum's permeability to water vapor. This measurement is widely used in the cosmetics industry and in dermatology research. However, only limited work has been undertaken to assess the comparability of results from different TEWL meters over an extended range of measurements.

This study compared the results of TEWL measurements between two commonly used open-chamber and closed-chamber TEWL devices. Five hundred and forty measurements were taken in 17 participants on the dorsum and palm of both hands on two different days and the order of the devices was randomized.

The results showed that the open TEWL meter's capacity for measuring high values of TEWL was restricted, and that the closed-chamber TEWL meter was less sensitive to differences in the lower range of measurements.

Both devices have their strengths for different applications, but their results cannot be directly compared. We were unable to find a statistical model that would allow us to transform the measurements made on one device for a comparison with the results generated by the other device.