Skin barrier in atopic dermatitis.

Research about the skin barrier and its properties has increased significantly since the 60s, with studies that indicated its resistance when isolated, as well as its particularities in relation to skin permeability. At the same time, description of Odland bodies helped to understand how stratum corneum stability is maintained. The âbrick and mortarâ model is the most accepted so far. In this analogy, the corneocytes are the bricks and the intercellular lipids are the mortar. Currently, there is concrete evidence that the stratum corneum is an active metabolic structure that holds adaptive functions, interacting dynamically with the underlying epidermal layers. The skin barrier also plays a role in the inflammatory response through melanocyte activation, angiogenesis, and fibroplasia. The intensity of this response will essentially depend on the severity of the injury. Skin barrier abnormalities in atopic dermatitis are clinically observed by the presence of dry skin, a common and significant symptom which constitutes a diagnostic and monitoring parameter. The stratum corneum hydration level and transepidermal water loss are associated with the level of damage to the barrier, representing biophysical parameters. These parameters help doctors monitor patients in a less invasive and more sensitive manner.