What is the Skin Barrier? And why is it so important?

Skincare has grown so popular in the past several years that it's common for people these days to have a 10-step routine. Although I'm not against a maximalist approach, there’s one aspect some might have taken a bit too far: exfoliating the hell out of your skin. We’ve become obsessed with the act of that squeaky clean type of cleansing. This strips our skin morning and night—we’ve over-washed, over-exfoliated, and overworked our poor skin barriers into oblivion.

What is the skin barrier?

Your skin is made up of layers, the skin barrier being the outer surface. Your skin barrier includes the stratum corneum, which is the outermost layer of the epidermis and is composed of lipids, skin cells, fatty acids, and amino acids. The skin barrier is pretty important, considering it’s what protects your skin from environmental aggressors (think UV rays and pollution), and also works to retain moisture within the skin. Without a strong skin barrier, your skin may become damaged.

The stratum corneum regulates epidermal water content, managing trans-epidermal water loss – through a delicate lipid membrane of waterproofing ceramides, cholesterol and fatty acids between the cells. Within the cells, a mixture of natural moisturising factor compounds maintains hydration by being hygroscopic (attracting water from the air).

  • It protects against oxidants from outside which can damage the skin – antioxidants.

  • It limits infection of the skin due to antimicrobial peptides.

  • Immune mechanisms respond to microbes, allergens and other invaders

  • It protects against damage from UV radiation

  • (It can signal disease states – providing an indication of internal illness)

  • Detect, protect, respond to, adapt against circumstances

How do you know if your skin barrier is damaged?

It’s not too difficult to discern whether your skin barrier has been compromised and damaged. Your skin barrier is likely compromised if you have red, irritated bumpy skin or excessive dryness and peeling. If your skin barrier is weakened, your skin will lose water easily and become dry and prone to developing eczema, a form of skin irritation. Plus, an impaired skin barrier can worsen acne, too.


How does skin barrier damage occur?

Unfortunately, there are multiple ways in which your skin barrier can be compromised, some of which you can’t really control. The changing weather is one contributing factor, especially during the winter. When humidity is low during these colder months, it’s more likely to dry out your dermis and cause moisture-loss, further weakening your skin barrier.

On the flip side, other factors that can contribute to a weakened skin barrier are ones within your control. Physical factors such as washing your face with surfactants can aggravate your skin barrier, as can using harsh exfoliating scrubs and brushes, Chemical factors can also impair your skin barrier—this includes using foaming cleansers that tend to be drying or using excessive amounts of active skincare ingredients such as alpha-hydroxy acids, salicylic acids, benzoyl peroxide, and retinoids. Additionally, essential oils common in many skincare products can also cause irritation and aggravate your skin barrier, too.

External stressors include:

  • Alteration of the pH, the normally acidic state of healthy skin, its ‘acid mantle’ – (ie through the use of alkaline soaps)

  • Aggressive or inappropriate skincare – cleansers with abrasives, exfoliants or additives that are irritants;

  • Use of astringents such as alcohol based toners

  • Reduced environmental humidity – winter heating and air conditioning

  • Photo damage – sunburn

  • Psychological stress

  • Exposure to irritants, allergens, microbial organisms

  • Topical medications, especially if poorly formulated

Internal stressors include:

  • Genetic or ethnic factors or age

  • Underlying diseases, such as eczema, rosacea, psoriasis – even when the disease is apparently under control or relatively asymptomatic

  • These factors cannot be changed, and so make the stratum corneum more vulnerable to external stressors

These stressors lead to

  • barrier damage,

  • Increased transepidermal water loss, reduced natural moisturising factors

  • Inflammation – release of cytokines – a cascade of changes

How to repair the skin barrier:

First off, it’s important to be using a simple facial moisturizer daily to keep your skin barrier healthy and to help improve acne—look for products with emollients and ceramides for added protection against the elements. Proper use of key skincare ingredients will help your skin maintain its health and avoid excessive irritation. You should avoid redundant skincare products, such as using an over-the-counter retinol alongside a prescription retinoid, or a retinoid with salicylic acid. If you use multiple chemical exfoliants, it's important to alternate the days you apply them.

When the barrier is challenged through external factors (seen most obviously in dehydration, inflammation, peeling), or where there are chronic skin disorders such as eczema or psoriasis or rosacea which affect the barrier, special care can be taken to help to repair its delicate balance.

  • Well-formulated gentle cleansers – without abrasives or soaps or alkalines. Preferably non-foaming.

  • Moisturizers which protect the barrier – containing humectants (to attract water to the skin), emollients (to soften the skin) and occlusives (to seal and prevent the loss of moisture)

  • Additives or actives which target specific problems or disease-related symptoms, ie lipids, humectants, niacinamide, antioxidants, amino acids

  • Increased acidification (associated with normalising of barrier function and reduction of allergic antigens)

Miranda Rojas