Lipidomics analysis of facial skin surface lipids between forehead and cheek: Association between lipidome, TEWL, and pH.

Phosphatidylserines exposure might be one of the most important reasons for the increased amount of forehead SSL secretion. The different FFAs chain length and FFAs content lead to altered skin barrier functions in forehead and cheek, consequently resulting in altered trans-epidermal water loss (TEWL) and pH at the two anatomical sites.