Capacitance and transepidermal water loss after soaking in water for different durations: A pilot study

Background There is a scarcity of data on the effects of duration of bathing and cutaneous properties. Aims This study aimed to investigate the changes of capacitance and transepidermal water loss (TEWL) after soaking in water for the different durations. Method This experimental biophysical study included healthy volunteers whose forearms were randomized to receive 3, 5, 10, 15, or 20 min of soaking of the volar aspect of the forearm. Skin hydration and integrity were assessed capacitance and TEWL measurement before and after soaking. Results Sixty-five subjects (130 forearms) were enrolled with an average age of 33 +/- 10.8 years. The change in capacitance after soaking for durations of 3, 5, 10, 15, and 20 min was 41.54 +/- 14.57, 47.13 +/- 11.80, 40.25 +/- 14.95, 40.48 +/- 14.19, and 39.97 +/- 9.47 AU, respectively. The highest capacitance was observed after soaking for 5 min; however, there was no significant correlation between bathing duration and capacitance (p = 0.256). The capacitance measured immediately after soaking was at the uppermost level, but it rapidly decreased within 5 min. The change in TEWL after soaking for durations of 3, 5, 10, 15, and 20 min was 30.27 +/- 9.74, 30.57 +/- 7.45, 33.78 +/- 9.25, 33.44 +/- 7.24, and 35.13 +/- 9.37 g/m(2)/h, respectively. There was also no significant correlation between duration of soaking and TEWL (p = 0.191); however, TEWL tended to increase with longer soaking duration. Limitations This study had a small sample size and measured only capacitance and TEWL. Future studies with more subjects, and that measure other physiologic parameters may further improve our understanding of the effect of bathing on skin. Conclusions There was no significant correlation between bathing duration and cutaneous properties including capacitance and TEWL. However, a 5-min soaking provided the highest skin hydration for healthy skin.