The development of skin barrier function in the neonate

The skin, one of the largest organs of the body, functions as a protective and regulatory barrier between the body and the external environment. At birth, infants must make the transition from a fluid intrauterine environment to dry, extrauterine life. Full-term infants, born at 40 weeks of gestation, make the transition with a competently formed barrier. However, the skin of the premature neonate comprises as much as 13% of the body weight, compared to only 3% of the body weight of an adult (1). In addition, the surface area to body weight ratio of the neonate is four times that of adults (2). Thus, the immaturity of the skin has numerous ramifications for the neonate, including ineffective thermoregulation (3), fluid imbalance (4), percutaneous absorption of toxins (2), tissue injury (5), infection (6), and delayed healing (7). Within the last decade, new technologies have changed the caretaking practices of the premature neonate; advances in respirator design, monitor technology, reduction of blood volume required for specialized tests, and the sophistication of new diagnostic techniques have all contributed to increasing the chances of survival of the premature neonate (8). Nevertheless, much remains to be learned about the complex extrauterine skin development of these neonates.