LAUSR

Purpose The transdermal application of carbon dioxide (CO2) gas dissolved in a solution and bathing in carbonated springs have been known to improve circulatory disorders. We aimed to elucidate and profile the effects of CO2 application on local skin function. Patients and methods A liquid formulation that included high-concentration CO2 or a control formulation was applied to the face of healthy men for 8 weeks. Quantitative analysis was performed during the dry winter months. Results At the site where the control formulation was applied, transepidermal water loss (TEWL) increased while the moisturizing function (conductance) of facial skin decreased during the study period. However, at the CO2-treated site, increases in TEWL and decreases in conductance were significantly suppressed. In addition, the deterioration in scaliness and wrinkles parameters were suppressed by ≥40% at the CO2-treated site. There were no significant differences in skin surface pH or color properties between the control and test sites. Conclusion This study suggests that the continuous application of a high-concentration CO2 formulation can affect skin physiology and has the potential to suppress reductions in the barrier and moisturizing functions of the stratum corneum accompanied by desquamation, which occurs during the winter.