Eczema is also sometimes referred to as atopic dermatitis or atopic eczema, but to keep things simple we'll just call it eczema. The skin of people who are prone to eczema is slightly different to those who don’t experience it.1 You'd be familiar with what eczema looks and feels like when it's flaring up – very dry skin with red and itchy areas.2 But what's going on when the condition isn't aggravated?
First, you need to understand the different components of your skin, and the job it does. Your skin is made up of three layers:3
The epidermis is the layer that's affected by eczema. The very top layer of the epidermis is called the stratum corneum – literally “horny layer” in Latin. This layer is made up of dead skin cells, squashed down flat and embedded in a matrix of lipids (more on that soon), like bricks and mortar.4,5 The stratum corneum is what keeps moisture locked into our skin, and if it's not working properly then moisture can escape, causing dry and dehydrated skin.1
Understanding the lipid matrix that glues your dead skin cells together is important to understanding eczema. This matrix is made up of different types of lipids, with three main ones doing the bulk of the work; ceramides, free fatty acids and cholesterol. When the balance of these three components is upset, the lipid matrix can't hold the dead skin cells together as well, allowing moisture to escape.6 Unfortunately, we don't yet know for certain what causes the components of the lipid matrix to disappear. It appears to be a combination of genetics, immune function or environmental factors.7 No matter the cause, once this barrier is impaired moisture can escape and environmental irritants can start to work their way inside, making your already dry skin inflamed and itchy.2 It's important to remember that scratching the itch further damages the skin's protective barrier layer.
Luckily, there are ways to help you manage your eczema-prone skin.