HUMAN NEWBORN SKIN - THE EFFECT OF ISOPROPANOL ON SKIN SURFACE HYDROPHOBICITY

The development of a hydrophobic skin surface in newborn mammals such as the rat plays an important role in promoting adaptation to the abru pt change in the environment that occurs at birth. To determine whethe r the skin surface plays a similar role in the human neonate, we perfo rmed tests of water sorption and desorption on the chest wall of 13 te rm newborns. These tests were performed within the first 24 h of life on unperturbed skin (controls) and after perturbation of a contralater al site with isopropanol. The degree of surface hydration was determin ed by measurement of skin surface electrical capacitance, and desorpti on rates were calculated by Ist-order kinetic analysis. The unperturbe d surface of the newborn skin exhibited a peak sorption value (change from baseline after water loading) of 435 +/- 83 pF (mean +/- SEM) and a desorption rate of 0.048 +/- 0.009 s(-1). After exposure to isoprop anol, the peak sorption value increased to 594 +/- 79 pF (p < 0.05) an d the desorption rate decreased to 0.024 +/- 0.004 s(-1) (p < 0.01). P aired sorption values were positively correlated (r(2) = 0.8, p < 0.00 1), These results support the hypothesis that the skin surface of the human newborn, by limiting the sorption of water (or amniotic fluid) o n the skin, may play a role in the adaptation to the change in environ ment at birth.