Transepidermal Water Loss in Young and Aged Healthy Humans

• Published in: Textbook of Aging Skin pp. 1197 - 1202
• Main Authors: Kottner, Jan, Vogt, Annika, Lichterfeld, Andrea, Blume-Peytavi, Ulrike
• Format: Book Chapter
• Language: English; Japanese
• Published: Berlin, Heidelberg Springer Berlin Heidelberg 2017
• Subjects: Corneocytes; Intercellular lipids; Skin barrier; Stratum corneum; Transepidermal water loss
• ISBN: 3662473976; 9783662473979
• DOI: 10.1007/978-3-662-47398-6_127

The stratum corneum is the most important barrier to a wide range of molecules, irritants, allergens, small particles, and microorganisms. However, small amounts of water continuously diffuse from the inside to the outside which is called transepidermal water loss (TEWL). TEWL is regarded as one of the most important parameters characterizing skin barrier integrity. Elevated TEWL is usually associated with skin barrier impairments, whereas reduced or low TEWL is considered as skin barrier integrity or improvement. Available evidence suggests that the water diffusion through the stratum corneum seems to remain stable and/or to decrease during aging. Possible reasons are the flattening of the corneocytes, altered and reduced intercellular lipids, reduced natural moisturizing factor content, and/or a reduced skin surface temperature. Such a “normal” TEWL masks the decreases of functional capacity of the skin barrier function in intrinsically and extrinsically aged skin.