Skin moisture

Skin moisture, or skin hydration, refers to the water content held within the layers of the skin, particularly the stratum corneum, and is a critical component of dermatological health and barrier integrity [1]. It is not a single molecular target such as a receptor or enzyme; rather, it is a complex physiological state regulated by natural moisturizing factors (NMFs), intercellular lipids (like ceramides), and proteins such as filaggrin and aquaporin-3 [2][3]. Adequate hydration is essential for the biochemical processes required for normal desquamation and the maintenance of a flexible, resilient physical barrier against pathogens and irritants [1]. Deficiencies in skin moisture are central to the pathogenesis of various conditions, including xerosis and atopic dermatitis, where an impaired barrier leads to increased transepidermal water loss (TEWL) [4]. Therapeutic strategies generally focus on topical applications of humectants to attract water and occlusives to prevent its evaporation, thereby restoring the skin's functional equilibrium [2][5]. Sources: [1] https://www.ncbi.nlm.nih.gov/books/NBK544224/ [2] https://pubmed.ncbi.nlm.nih.gov/22152307/ [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3396454/ [4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5605222/ [5] https://pubmed.ncbi.nlm.nih.gov/28582736/

Other names

Skin hydrationStratum corneum hydrationEpidermal water content

Drugs and topical agents maintain skin moisture through three primary mechanisms: humectants (e.g., glycerin, urea) attract water from the dermis and environment into the stratum corneum; occlusives (e.g., petrolatum) form a hydrophobic barrier to reduce transepidermal water loss (TEWL); and emollients (e.g., lipids) fill gaps between desquamating corneocytes to smooth the skin surface [1][2].