Eczema Explained

Eczema, or dermatitis as it is sometimes called; is a very common condition which causes itching, dryness and thickening of the skin. In the United Kingdom, up to one fifth of all children of school age have eczema, along with about one in twelve of the adult population. To explain what happens with the eczema, it is necessary to understand the structure of the skin as seen down a microscope. The skin consists of three layers: the outer layer is called the epidermis - one of the areas affected by eczema. This contains a 'brick wall' of skin cells (keratinocytes) that are held together by a 'cement' mostly made up of fats or lipids. The skin cells constantly reproduce to replace the daily shedding of dead cells from the surface. The lipid cement acts as a barrier against the environment. It prevents the skin losing too much water and prevents noxious (poisonous) substances getting in. The middle layer of skin is called the dermis - another area affected by eczema. This consists of tough structural fibres called collagen and elastin, which provide strength and elasticity to the skin. It also contains blood vessels that supply nutrients and oxygen to both the dermis and the epidermis. The deepest layer of skin is called the subcutaneous layer and is made up predominantly of an insulating layer of fat - not surprisingly this isn't affected by eczema!

As mentioned above, in eczema it is the dermis and epidermis skin that are affected; with the epidermis showing the most marked changes. The inflammation leads to leaky blood vessels and fluid collects between the keratinocytes, causing them to separate and the brick wall takes on a sponge-like appearance in the skin. The constant rubbing/scratching causes the epidermis to regenerate more quickly, and so it becomes thickened - leading to eczema. Eventually, eczema causes changes in the upper part of the dermis. This region of the skin becomes flooded with white blood cells; which are part of the body's immune system or defences. They leak out of the vessels and even pass up into the epidermis.

There are a number of ways to manage eczema, all of which begin with an effective skin care routine. Having access to accurate information is important as this allows the person with eczema, or their carer, to make informed choices when managing the condition. Symptoms of mild eczema is an area of fine, dry scaling, often on the arms or legs. The skin may or may not itch. Severe eczema (usually inherited) causes intense itching, most commonly on the fronts of the elbows, backs of the knees, and face; however, any area of skin may be affected. The skin is usually very sensitive to being touched. Even a light touch may cause itching. Many people who have severe eczema are quite sensitive to scratchy fabrics, like wool. Eczema often becomes worse during times of stress and in the winter, when the air is very dry. It should be stressed though, that eczema is not contagious!