In a state of epidermal barrier disruption characterized by increased TEWL and reduced epidermal water content, a properly formulated moisturizer can act in a manner similar to endogenous epidermal lipids in promoting and restoring epidermal barrier function (1-3,13-24). Lipids applied externally in moisturizer formulations intercalate between corneocytes and have been shown to reduce surfactant-induced skin […]

A pivotal component of epidermal barrier formation is the synthesis within nucleated keratinocytes of the intercellular lipid bilayer, a functional permeability barrier composed of specific lipids present in proper ratio. Epidermal barrier lipids are autonomous from lipids circulating in the bloodstream and are composed predominantly of equimolar concentrations of free fatty acids, cholesterol, and ceramides […]

Normal skin appearance, water balance, and continued barrier integrity necessitate an intact epidermal barrier with maintenance of the proper water content required for physiologic and enzymatic functions. As the epidermis is a living dynamic unit, several physiologic functions continue as an ongoing process, with perturbations of barrier integrity requiring necessary adjustments and repairs before the […]

Proper skin cleansing and moisturization are the two basic processes that must work in harmony to maintain overall skin health and epidermal barrier integrity (1,2). The role of skin cleansing is to remove external debris, cutaneous secretions, and microorganisms. In addition, the integrity of the epidermal barrier must be consistently maintained to allow for cutaneous […]

James Q. Del Rosso Department of Dermatology, University of Nevada School of Medicine, Las Vegas, Nevada, U. S.A. Due to consistent marketing influences promoting multiple products that claim “removal of fine lines, wrinkles, and age spots,” consumer demand for products that provide a “fresh look and a more youthful appearance,” television and written advertising media […]

New and exciting discoveries have been made in SC biology over the last decade, but more importantly the understanding of the aberration of the normal functioning of the SC in dry, flaky skin conditions has become clearer and a new model of dry skin has been described. On perturbation of SC barrier function, a futile […]

Changes in lipid levels and types can be corrected by topically applying agents to manipulate the lipid synthesis process within the viable epidermis. However, as described above, in dry skin conditions the epidermis makes less phytosphingosine-containing ceramides, changes the carbon chain lengths of other sphingoid bases and synthesis less long chain fatty acids. These results […]

Ligands for nuclear receptors such as the peroxisomal proliferator activated receptor have been shown to improve epidermal differentiation, increasing ceramide and filaggrin levels (122). This superfamily of nuclear transcription receptors includes the retinoic acid receptors, the steroid receptors, the thyroid receptors, and the vitamin D receptors and also the peroxisome proliferator activated receptor (PPAR), together […]

Hydroxy acids are being used to facilitate desquamation and improve lipid biosynthesis together with barrier function. The influence of alpha-and beta-hydroxy acids (115) on desquamation is now well established, but new lipophillic variants of salicylic acid appear to influence corneodesmolysis differently. Whereas lactic and salicylic acid act on all corneodesmosomes, LSA only acted in the […]