257 Water Content in Infant Stratum Corneum

Abstract

Objective: To determine the water content of infant stratum corneum (SC) as compared to adult and identify the sources of differences. Methods: We have acquired in vivo Raman spectra from the forearm skin of 15 infants (3-24 months) and their biological mothers. The Raman spectra were analyzed for the water content, the thickness of SC, and the concentration of components of natural moisturization factor (NMF). We also collected skin conductance data on the forearm of 67 infants of the same age and their mothers. Results: As previously reported conductance values and water concentration profiles are significantly higher in infant skin compared to adult. In agreement with published data from confocal microscopy, Raman data also show that infant SC is 30% thinner than adult. Even after accounting for the differences in SC thickness our data show that water content in the top layers of the SC is still significantly higher in infants compared to adults (20% more at the top quarter of SC). NMF analysis showed that although adults have more amino acids, infants have significantly more lactate in their SC. Conclusions: Infant SC contains more water than adult. Lactate may be responsible for at least part of this increased water content. Water stored in microrelief lines may be an additional explanation for the higher skin conductance values in infant skin.