LC-MS/MS Quantification and Comparative Profiling of Stratum Corneum Ceramides in Human Normal and Dry Skin Subtypes

: This method offers a reliable tool for the quantitative analysis of ceramides in dermatological, physiological, and pathological research. The findings not only underscore the profound heterogeneity in lipid metabolism underlying different dry skin subtypes but also provide a molecular rationale linking aberrant ceramide chain lengths to compromised barrier integrity and heightened inflammatory susceptibility. The partially validated analytical platform and the specific ceramide signatures revealed herein offer valuable tools and insights for advancing the mechanistic understanding, diagnosis, and targeted intervention of sensitive dry skin.