Infant Skin Barrier, Structure, and Enzymatic Activity Differ from Those of Adult in an East Asian Cohort

Skin physiology is dynamically changing over the frst years of postnatal life; however, ethnic variations are still unclear. Te aim of this study was to characterize infant skin barrier function, epidermal structure, and desquamation-related enzymatic activity as compared to that of adult skin in an East Asian population. Te skin properties of 52 infants (3-24 months) and 27 adults (20- 40 years) were assessed by noninvasive methods at the dorsal forearm and upper inner arm. Transepidermal water loss and skin surface conductance values were higher and more dispersed for infants compared to adults. Infant skin surface pH was slightly lower than adult on the dorsal forearm. Te infant SC and viable epidermis were thinner compared to adults with diferences that were site-specifc. Although the chymotrypsin-like activity for infant skin was comparable to adult level, the caseinolytic specifc activity was signifcantly higher for the infant cohort. Tese observations indicate a diferently controlled pattern of corneocyte desquamation in infants. In conclusion, structural and functional diferences exist between infant and adult skin in the East Asian population pointing to dynamic maturation of the epidermal barrier early in life.