Effects of fluid volume changes during hemodialysis on the biophysical parameters of the skin.

Water plays an important role in maintaining skin suppleness and elasticity. We used hemodialysis as a model to investigate the effects on biophysical properties of the skin induced by removal of fluids and water from the body. The following parameters have been investigated before and immediately after a hemodialysis session: body weight, skin elasticity and distensibility, skin hydration, transepidermal water loss (TEWL) and skin thickness. A significant decrease was recorded after treatment in body weight, skin thickness (p < 0.01) and skin elasticity (p < 0.01). Significant linear correlations were found between stratum corneum water content, skin distensibility and TEWL. The data reveal that rapid removal of body fluids influences skin biophysical properties: early changes in skin thickness and ground substance occur in the dermis and affect mechanical properties of the skin. The decrease in water content in the upper layers of the skin occurs at a later stage and influences skin hydration rather than TEWL. This model is a useful tool to investigate water kinetics through the skin.