A recent article in Nature Reviews/Disease Primers reviewed the current knowledge on atopic dermatitis (AD), established treatments and the study of changes in the skin that results in this skin condition.
Atopic dermatitis or atopic eczema is the most common form of eczema. It is a non-contagious inflammatory skin condition and is recognisable by red, dry, itchy skin which can sometimes weep, become blistered, crusted and thickened. Itch is the most troublesome symptom and can affect quality of life.
How many people are living with AD?
Globally it is estimated that 230 million people have symptoms of AD, affecting 1 in 5 children and 1 in 12 adults in Ireland. It can start at any time in life but is most common in childhood. AD can run in families and frequently occurs alongside other atopic conditions, including asthma, hay fever and food allergies.
AD involves a complex interplay of the following, skin barrier dysfunction owing to a deficiency in the structural protein filaggrin, abnormal immune system responses and an imbalance in the skin microbiota.
The mortar that ties your skin together
Filaggrin (a skin protein), ties skin cells together and helps to form part of the natural moisturising substance within the top layer of the skin, which prevents your skin from drying out.
Some people with eczema have a mutation, in their filaggrin, which results in lower overall levels of this important mortar and causes their skin barrier to be weaker.
When your skin becomes too dry, irritants can enter triggering an immune reaction. Once the immune system is triggered, this results in red, inflamed itchy areas you can see on your skin.
A community of organisms living on your skin – microbiota
Another contributing factor is the imbalance in the skin microbiota. Staphylococcus aureus is a type of bacteria which is found frequently on the skin in healthy people and an overgrowth could be another contributing factor in AD.
Depending on the severity of AD, management includes topical therapies, anti-inflammatory drugs, phototherapy and immunosuppressant medications.
New treatments on the way
This improved understanding of skin barrier dysfunction is contributing to the development of new effective drugs (biologics). These next generations treatments will work by targeting abnormal immune pathways and will be the driving force behind prevention studies based on ‘barrier therapy’.
Reference: Weidinger, S., Beck, L.A., Bieber, T., Kabashima, K. and Irvine, A.D., (2018). Atopic dermatitis, Nature Reviews Disease Primer, 4: 1