The skin is the body’s largest organ. A well-known fact that most of us have heard at least once, be it at school or in a quiz of some kind. We all also know that the skin is important for things such as appearance, temperature regulation and, perhaps most importantly, protection. But what exactly do we mean by ‘protection’? That is where the skin’s barrier function comes in.
What exactly is the skin’s barrier function?
The skin’ barrier function relates to its ability to act as the body’s first line of defence to the outside world; keeping all the good things like moisture in and all the bad things like irritants and allergens out.
Rather than one simple layer, the skin is actually made up of three primary layers: the hypodermis (deepest layer), the dermis (middle layer) and the epidermis (upper layer). These layers are each made up of different sublayers, but it is one sublayer in particular that is crucial to the skin’s barrier function: the outermost layer of the epidermis, also called the stratum corneum.
The stratum corneum literally forms the protective barrier between the inner body and the outer world1; it is the vanguard that helps to keep us healthy and safe. The stratum corneum is made up of approximately 15-25 layers of dead skin cells, called corneocytes, embedded within a lipid bilayer2 which forms a sort of “brick and mortar” wall3.
Why is it important to help maintain the skin’s barrier function?
The proper functioning of the stratum corneum is crucial for the proper barrier function of the skin in general. If it is working correctly, things like allergens and irritants have a very hard time getting in, and important things like moisture have a hard time getting out. On the other hand, if the barrier isn’t working properly, moisture can escape, leading to dryness, and all those allergens and irritants can have a field day. To continue the brick wall analogy, if the bricks and mortar aren’t in prime condition, the wall isn’t going to be very effective if it starts crumbling.
A compromised barrier function, either through water loss or the entry of irritants or allergens in through the skin can not only lead to dryness, irritation and discomfort, but can worsen the symptoms of many skin conditions, including eczema4.
How do I support my skin’s barrier function?
Some general tips can help substantially, including: