Skin barrier properties in the newborn. Transepidermal water loss and carbon dioxide emission rates.

Relative permeabilities of newborn and adult skin to small molecules were determined by measuring emission of carbon dioxide and water vapor through skin. Transepidermal water loss (TEWL) measured on the forearm of 22 term infants was lower than that observed in 30 control adults (0.31 +/- 0.09 vs. 0.39 +/- 0.15 mg/cm2/h). There was no significant difference between newborn carbon dioxide emission rates (CDER) and adults CDER. When environmental temperature was raised from 74 to 80 derees F, large dramatic increases in adult TEWL were observed in contrast to small increases in newborns. This phenomenon suggests diminished eccrine activity in the newborn. No correlation of TEWL or CDER with respect to birth weight, sex, age or gestational age was observed. Similar permeability to carbon dioxide in neonates and adults and a decreased TEWL in neonates compared to adults suggest that even at birth the skin functions as an efficient barrier to these molecules, penetration rates, in adults, of other polar compounds should be similar to those in neonates.