At first sight dehydrated and dry skin may sound similar and refer to the same thing. In fact, this is not true. Dehydrated and dry skin refer to two different conditions of the skin. In this blog we will explain the difference between those two terms and we will tell you something more about the causes and treatments of these two conditions.
Our skin cells form a barrier that protects our internal system against external and environmental stress factors and helps to prevent trans-epidermal water loss. The upper skin layer (epidermis) can be represented as a “brick and mortar model”, consisting of a 2-compartment system with a discontinuous phase (brick) that represents the corneocytes and a continuous phase (mortar) that represents the lipids in the skin.
The skin cells renew and move upwards to the surface of the skin. During this renewal process they also form byproducts that help to build up the skin barrier. On the one hand there is the ‘natural moisturizing factor (NMF)’, consisting of a mix of substances which maintains the natural hydration level of the skin. On the other hand, there are also sterols, fatty acids and ceramides in the intercellular space of the skin that help to form the lipid bilayer of the skin. These 2 key components work together to form the skin barrier, that keeps the skin hydrated and resilient.
If your skin is dehydrated, it simply means that there is a (temporary) lack of water in the skin. The skin is not able to retain enough water into the different skin layers. A dehydrated skin is a skin condition and can happen to everyone, even people with an oily skin type can have a dehydrated skin. High water loss/dehydration can be caused by different factors affecting NMF’s and/or the lipid bilayer. There are a lot of external factors that can cause a dehydrated skin. The most common ones are:
- Temperature changes: cold, wind, sun exposure
- Hot showers and baths
- Central heating & air conditioning
- The wrong skincare products: harsh & aggressive ingredients
- An excessive lifestyle: alcohol, too much caffeine, smoking, lack of sleep, a poor diet
When we speak about a dry skin, we refer to a skin type that is lacking lipids (mortar) in the skin. In most cases a dry skin is genetically determined, although, it can also be caused by using oil-control products that are too harsh and strip of the natural intercellular lipid layer on the skin.
One cannot exist without the other?
It is important to know that a lack of water (dehydrated skin) and a low amount of oils and lipids (dry skin types) are closely associated. The “brick and mortar” structure of the skin, in which the mortar consists of lipids that act as gatekeepers of the skin to keep water into the skin, preventing its evaporation. When the lipid balance of the skin is disturbed (due to genetic and/or environmental factors), the structural integrity of the skin barrier is lost, resulting in an increase of the trans epidermal water loss. So dry skin inherently also leads to a dehydrated skin.
It is difficult to know whether your skin is dry or dehydrated, as they share similar characteristics when it comes to ‘the feeling of your skin’. Both conditions are often accompanied by a skin that feels tight and rough, looks dull and/or tired and has a flaking, scaling, cracking texture, with visible redness.
By examining your DNA, we can gain more insights into your skin profile. In the lab, Nomige investigates whether you have variations or mutations in the genes that help keep the skin barrier intact and help control the moisture balance; namely Fillagrin (FLG) and Aquaporin-3 (AQ3). Based on your DNA profile, we know what risks you are carrying for a dry/dehydrated skin and we develop products whose ingredients can help counteract these risks.
When you are suffering from a dry or dehydrated skin but we cannot find any risks in your DNA, external factors can also be the cause of your dehydrated skin. In this case it is important to first identify these external factors, by filling in our lifestyle test.
For a dehydrated skin it is primarily important to restore the water balance in the skin. This can be done by using hydrating agents, such as humectants. Examples of humectants are:
- Butylene glycol;
- Glycerin, probably the most popular;
- Propylene glycol;
- PCA (Pyrrolidone carboxylic acid);
- Lactic acid;
- Hyaluronic acid
While for a dry skin, restoring the lipid balance and maintaining a strong barrier is very important. This can be done by using skin-identical lipids to replenish the ‘mortar’ in between the cells. Examples are:
- Free fatty acids
Another, less favorable way of hydrating your skin, is via occlusion. Think about ingredients such as paraffinum liquidum, wax, …You simply add a layer to your skin making it ‘lazy’ instead of constructively restoring it. When you stop using such creams your skin will feel even more dry, so you end up in a viscous circle. The better alternative is to use skin care products containing skin identical lipids (such as ceramides, cholesterol, …), humectants (such as glycerin, ureum, …) or ideally a combination of both.
In addition to using the right moisturizer for your skin, avoid harsh cleansers that damage your natural skin barrier. If you want to know more about how to gently clean your skin, read our previous blog: ‘cleansing: why, how and when?’