Water (H2O) in dermal tissue (H2O)

Extracellular water in dermal tissue is a fundamental component of the skin's extracellular matrix, providing the necessary hydration for structural integrity, elasticity, and metabolic processes. It is primarily sequestered by glycosaminoglycans, such as hyaluronic acid, which can hold up to 1,000 times their weight in water (Papakonstantinou et al., 2012). In clinical practice, this water serves as a critical therapeutic target for both aesthetic and medical interventions. For instance, humectants and injectable fillers aim to increase or retain dermal water to treat xerosis and signs of aging (Sethi et al., 2016). Additionally, water acts as the primary chromophore for various ablative and non-ablative lasers, which target water molecules to induce controlled thermal injury for skin rejuvenation and scar revision (Anderson & Parrish, 1983). Proper regulation of dermal water is essential, as imbalances can lead to clinical conditions such as edema or premature skin aging (StatPearls, 2023).

Other names

Dermal waterInterstitial fluid of the dermisCutaneous water contentExtracellular dermal fluid

Drugs and therapeutic agents interact with dermal water through several mechanisms: humectants (e.g., glycerin, urea) form hydrogen bonds with water molecules to retain moisture in the stratum corneum and dermis (Sethi et al., 2016); injectable fillers like hyaluronic acid physically sequester water to provide volume; and medical lasers use water as a chromophore, where the absorption of light energy by water molecules leads to localized heating and tissue remodeling (Anderson & Parrish, 1983).