If your skin is healthy on its surface, you have what's known as the skin barrier. It's made up of a matrix of sebum, which is natural skin oils, sweat and dead skin cells. It acts as a natural defence system for the skin, maintaining a slightly acidic pH level so that it instantly kills any bacteria that it comes into contact with. Additionally, it helps to lock in and retain moisture to reduce trans-epidermal water loss and prevent dry skin.
Wait!I thought the skin cells on the top of my skin were dead?
The outer layer of your skin is made up of horny cells, which are keratinocytes, that have had the nucleus deactivated.The corneocytes mesh together with the oil in your skin to create a protective barrier. Although the cells on the surface of the skin are technically dead, they do still perform a very important function in the overall health of your skin.
I'm sure you are familiar with the skincare concept of removing the dead cells on the surface of the skin in order to reveal the fresh, healthy cells underneath. Unfortunately, all this does is expose young skin cells to the environment prematurely and remove the skin's natural defence barrier.
Products which perform this function such as exfoliants, chemical peels, microderm abrasion, and dermal planning all interrupt and damage the skin's protective mechanism.
With the skin barrier damaged or removed, and the skin cells underneath prematurely exposed to the environment, the skin then is susceptible to dirt and bacteria, which can cause acne, black head sensitivity, dryness, and eczema, which is how, and why a healthy barrier can prevent up to 90% of skin conditions.
The good news is that if you do have a damaged barrier, it will reform if you create the right environment and stop doing things that continue to redamage it. And if you are experiencing acne, black blackheads, dry skin sensitivity, or eczema, and there's a good chance that you do have a damaged barrier.
If you're using any of the products or treatments I listed earlier, I recommend that you stop them in order to give the barrier time to heal.