Changes in diapered and nondiapered infant skin over the first month of life

Time- and site-dependent differences in epidermal barrier properties were i nvestigated over the first 28 days of life in healthy term newborn infants. Diapered and nondiapered skin sites were contrasted to the volar forearm o f adults (mothers), Thirty-one term infants were evaluated in the hospital on postnatal day 1 and at home on days 4, 7, 14, 21, and 28 for a total of six visits. Measurements included baseline skin hydration, continuous capac itive reactance, peak water sorption, rate of water desorption, skin pH, sk in temperature, and environmental conditions. Changes in epidermal barrier properties over the first 4 weeks of life included an increase in surface h ydration, a decrease in transepidermal water movement under occlusion, a de crease in surface water desorption rate, and a decrease in surface pH. Diap ered and nondiapered regions were indistinguishable at birth but exhibited differential behavior over the first 14 days, with the diapered region show ing a higher pH and increased hydration. Maternal measurements remained con stant throughout the period. We conclude that healthy newborn skin undergoe s progressive changes in epidermal barrier properties over the first 28 day s. Adult skin testing does not replicate newborn skin during the first mont h of life.