Discover the characteristics of sensitive skin to better understand your skin's needs.
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○ An alteration of the skin barrier○ A reduction in the skin’s tolerance threshold
○ Nervous sensitivity
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DID YOU KNOW ? Skin sensitivity can be caused or aggravated by numerous exogenous and endogenous factors: Pollution, temperature variations, unsuitable cosmetics, consumption of stimulants, stress, fatigue, etc. |
FOCUS ON THE ORIGINS OF SKIN SENSITIVITY
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FOCUS ON THE ORIGINS OF SKIN SENSITIVITYAlteration of the skin barrier due to water loss and lipid modificationIn the stratum corneum, water molecules attach to hygroscopic and water-soluble intracellular molecules called " Natural hydration factor » or NMF which have a strong osmotic potential thus attracting water molecules. They are contained in corneocytes, cells of the upper layer of the epidermis called the stratum corneum. The components of MNF are mainly amino acids, pyrrolidone carboxylic acid, lactic acid, urea, glucose and mineral ions. The skin's natural flow of hydration rises from the deepest layers to the surface. This flow is possible thanks to aquaporins which selectively conduct water molecules inside and outside cells, while preventing the passage of ions and other solutes. Also known as water molecule channels, aquaporins are membrane proteins that form “ pores ". Skin hydration is also regulated by the selective permeability of the stratum corneum and the hydrolipidic film together forming the skin barrier. It limits insensible water loss and protects the skin from the entry of irritants. Its permeability depends on the integrity and nature of the lipids between the corneocytes also called intercellular cement. |
Any change in this balance can result in an alteration of the skin barrier causing water loss and abnormal penetration of irritants.
Reduction of the skin's tolerance threshold inducing excessive synthesis of pro-inflammatory cytokines
Sensitive skin will react to irritants and external factors that have no effect on normal skin. This sensitivity results in excessive synthesis of pro-inflammatory cytokines which have the role of activating the inflammation process.
Nervous sensitivity
Human skin has many sensory nerve fibers reaching the bottom of the epidermis. They are what allow the central nervous system to know the condition of the skin and to react to different chemical, thermal and physiological stimuli. An exaggeration of the nervous response and a low activation threshold are involved in the phenomenon of skin sensitivity.
