Assessment of the variation of skin barrier function with anatomic site, age, gender and ethnicity

The skin is the largest organ of the human body and its functions include protection, thermoregulation sensation and secretion. Significant advances in our understanding of how the morphology and physiology of the skin contribute to the skin's barrier role have been achieved in recent years. The aim of this review is to summarize the principal approaches which have been used to assess variation in skin barrier function with anatomic site, age, gender, and ethnicity. The methods discussed include trans-epidermal water loss (TEWL) measurement, assessment of corneocyte size, response to vasoactive compounds and attenuated total reflectance Fourier transform infrared (ATR-FTIR) interrogation of skin. The utility of the various methods is considered and the most important findings in the literature to date are highlighted.