What Causes Eczema/ Atopic Dermatitis
At present the underlying cause for eczema is not understood. There has been vast amounts of research in this area over the last 25 years and several theories have been put forward.
Eczema is likely to be due to a number of factors including;
1. Genetic factors : The importance of genetic factors is underlined by the finding that a positive parental history is the strongest risk factor for eczema. Studies have shown that parental eczema confers a higher risk of eczema to offspring than parental asthma or allergic rhinitis. These findings suggest the existence of specific genes for eczema, rather than or in addition to atopic genes.
2. Environmental factors : There are a number of theories around the relevant environmental influences such as increasing exposure to allergens such as the house dust mite and reduced exposure to childhood infection having an effect on delayed “maturation” of the immune system, but this question remains of great interest and is un-resolved.
Reecent work published by experts on genetic skin disorders at the University of Dundee, with collaborators in Dublin, Glasgow, Seattle and Copenhagen, have discovered the gene that causes dry,scaly skin and predisposes individuals to atopic dermatitis (“eczema”) in a large percentage of the European population. Some of these individuals also develop a form of asthma that occurs in association with atopic dermatitis. This work has been published in two consecutive papers in the March and April editions of the top genetics journal, Nature Genetics.
The gene in question produces a protein called filaggrin which is normally found in large quantities in the outermost layers of the skin. This protein is essential for skin barrier function, helping to form a protective layer at the surface of the skin that keeps water in and keeps foreign organisms out.
In eczema this barrier is found to be abnormal due to a lack of the protein filaggrin.
and this can make the skin prone to further insult from irritants such as water, resulting in inflammation and a flare of eczema.
