Infant skin has marked differences in structure, function and composition compared to adult skin. In Vivo Studies Through in vivo video microscopy, it has been shown that compared to adult skin, infant skin surface has a denser network of furrows called microrelief lines, which can act as traps and reservoirs for external irritants. In vivo reflectance confocal laser scanning microscopy also showed that the stratum corneum and supra-papillary epidermis are both thinner in infants, which shortens the penetration path for irritants, contributing to a reduced skin barrier function. In terms of composition, in vivo Raman confocal microspectroscopy revealed greater water content in infants compared to adults. Natural Moisturizing Factor (NMF) of Infant Skin In comparison to adult skin, these components of the natural moisturizing factor in infant skin are lower: - Amino acids - Urea - Pyrrolidone carboxylic acid - Other substances This limits the infant skin ability to hold on to water. These structural and compositional differences have clear effects on the physiology of infant skin compared to adult skin, such as: - Lower skin barrier function - Higher transepidermal water loss Environmental Exposures Due to the dynamic nature of infant skin, it is also vulnerable to environmental exposures, including skincare products, during this critical time of skin development. Such exposures may affect the process of skin maturation, as well as the microbial balance that accompanies skin development. Hence, there is a need for infant skincare products that help establish healthy skin function to protect infants from external aggressors. Click here for references.