Forming Barrier Function
A functional dermal barrier is essential if you want to have healthy skin. This is something I find myself talking about and helping clients with on a daily basis.
Whether it be acne or ageing, we need to help our skin’s natural barrier function by avoiding the stripping of our stratum corneum, so as to avoid further problems.
The stratum corneum is the waterproofing layer that keeps moisture in the skin and prevents the penetration of chemicals and bacteria.
In a nutshell, the shells of the dead cells (corneocytes) are “glued” to eachother by chemical lipid bi-layers, as well as by the remnants of the desmosomes that originally connected the cells together.
Because this is mainly a lipid (fat) barrier, lipid-soluble molecules can enter the skin more easily than water-soluble ones. Photo-damage AKA ageing makes the horny layer build up and thicken, causing dull-looking skin. It can also force the cells to develop abnormally.
The skin’s natural exfoliation process slows down with age to almost half its rate by age 30. Clients always notice this when we get talking about it and it usually leads them to seek me out for the treatment of rough, thickened skin, as well as adult acne. Problematic and sun-damaged skin can also have a very thick stratum corneum of up to 25 sheets.
Maintaining the surface of the stratum corneum is also important to protect us from infections, because normally there is a layer of oils secreted from the sebaceous glands, sweat glands, etc., that help to form the “acid mantle” of the skin.
This has a natural pH of 4.5 to about 6.5 and inhibits the growth of bacteria and fungi.
Since our bodies are mainly composed of water, we need the dry cells to be the interface between us and the extremely harsh and dry atmosphere.
Therefore this layer has to prevent the loss of water from our bodies so that we do not dehydrate. On the other hand, it also has to prevent the flow of water into our bodies when we are immersed in water. If it did not, we would become water-logged and drown when we swim or have a bath.
Unfortunately, when exposed to the environment prematurely, these immature cells rapidly dry out without the advantage of normal maturation, so they become inefficient stratum corneum cells with inadequate lipid bi-layers. They are also damaged by exposure to oxygen from the atmosphere and are hence attacked by free radicals.
While this may be relatively unimportant if an exfoliation procedure is performed regularly, it becomes more important to correctly cleanse and exfoliate without stripping our precious natural skins barrier.
The important message of an effective skin care system is that the horny layer is a highly developed, sophisticated, delicate membrane that we desperately need to help protect us from the harshness of our environment.
Our efforts should be concentrated on preserving this thin layer of cells and avoiding any destructive procedure that results in the scarring of the epidermis.
