Anatomical site variation of water content in human skin measured by the Epsilon: A pilot study

Abstract

Background: This pilot study aimed to investigate the anatomical site variation of water content of the stratum corneum (SC) on the body by measuring skin capacitance with the Epsilon, a new generation corneometer with multiple sensors. Secondly, values of the Epsilon were compared to values measured by conventional single sensor corneometers.

Methods: The hydration status of SC was measured in 15 healthy Caucasian volunteers with the Epsilon at five body sites (cheek, lower forearm, mid-calf, lower back and abdomen). Transepidermal water loss (TEWL) was measured with the Aquaflux to get more insight into the condition of the skin barrier. A literature search was performed to compare Epsilon values with conventional corneometers.

Results: The tested anatomical locations showed significant differences in water content (P < 0.001) with large interindividual variations; highest values were found in the cheek (11.64ε) and lowest values in the mid-calf (4.43ε). No correlation between water content and TEWL was found. In general, Epsilon values were lower compared to values of conventional corneometers, with a similar trend.

Conclusion: This pilot study showed significant variations in water content at different skin locations measured by the Epsilon. Moreover, the Epsilon measured consistent lower values compared to single sensor corneometers. Further validation of the device is recommended.

Keywords: Epsilon; corneometer; skin barrier; skin capacitance; water content.

Figure 1

The Epsilon is a novel instrument for measuring near‐surface dielectric permittivity (ε) and contact imaging of the skin. Its proprietary electronics and signal processing algorithms map the sensor's nonlinear signals onto a calibrated scale for measuring properties such as stratum corneum hydration. A, The Epsilon instrument on the parking stand. B, A measurement performed on the inner arm. C, Close‐up of the Epsilon measurement head with the metal bezel. D, The sensor surface embedded in an epoxy frame. E, Typical contact image of the inner forearm skin. F, A contact image of the skin in the face with visible sweat gland activity

Figure 2

Measurement locations of water content and transepidermal water loss (TEWL)

Figure 3

Water content at five body sites measured with the Epsilon. The values are expressed as median with interquartile range and range (minimum‐maximum)