We’re still at the letter A and the last one was on the confusing nomenclature of Eczema versus Atopic Dermatitis. This week (pardon last week’s absence, can’t promise it won’t happen again though as I’m so tied up with work, family and doing other things I enjoy) we’re onto Atopic March. Sometime last year, DrFelix.co.uk (a registered online UK doctor and pharmacy service) contributed a write-up on Atopic Triad, which covers eczema, asthma and allergic rhinitis (hay fever).
Atopy is a genetic tendency to develop certain allergies. Most commonly, Eczema, Asthma and Hay Fever. In fact, if either parent has at least one of the three, there is a high chance that their child will also develop the condition. In these three ailments, the body areas become inflamed and produce excess immunoglobulin E (IgE) in response to harmless stimuli such as dust or pollen.
It is very common for people who experience eczema to also have asthma and hay fever. The connection between these conditions can be summarised by one word: hypersensitivity.
The body including the skin and respiratory system are over sensitive towards certain substances and they overreact when exposed. Rashes on the skin and a congested nose are all ways in which the body is trying to protect itself from something that it deems to be harmful. Unfortunately, this overreaction can be very uncomfortable and unnecessary.
There are also other connections between the Eczema and the development of Asthma. 50-70% of children with Eczema go on to develop Asthma. Recent research undertaken by Washington University School of Medicine has discovered that Eczema damaged skin produces a protein called thymic stromal lymphopoietin (TSLP). TSLP has also been found to directly cause asthma symptoms. This research is still in its early stages and this mechanism has not yet been fully confirmed in humans, but it shows a promising new direction for pharmaceutical research that may be able to stop the development of secondary conditions in their tracks.
Byline: Dr Samuel Malloy, Medical Director at DrFelix.
We understand that atopic conditions are related, in the sense one’s hypersensitivity may manifest in other than skin. But what about the term Atopic March? Does one condition literally marches your child off to another?
While it is more commonly noted that Atopic Dermatitis (Eczema) progresses to asthma and hay fever, the progression is not the same for every child.
Some recent research on this:
Skin Barrier Dysfunction and Atopic March 1 – It was noted in the study that the atopic conditions should be viewed as causally related, as they are conditions related to the lack of filaggrin gene. Recent studies on skin barrier dysfunction suggest that if we can treat the skin defects early, there is a chance of stopping the progression to other atopic conditions.
The Atopic March: Progression from Atopic Dermatitis to Allergic Rhinitis and Asthma 2 – It was noted that the “concept of the atopic march has been supported by cross-sectional and longitudinal studies“; however, “whether AD in the march is necessary for progression to other atopic disorders remains to be defined”. The conclusion was that it is important to identify infants at risk as it presents a critical window of opportunity for therapeutic intervention.
Increasing Comorbidities Suggest that Atopic Dermatitis Is a Systemic Disorder 3 – The associations (even though causality is not proven) showed that AD is linked to the whole body, not just the skin.
Thus, while we see a progression of atopic conditions in a majority of children with eczema, it may not be a “march” of one onto another – not all children undergo the progression, and a few conditions may co-exist. What looks certain (and practical) is that there is urgency to treat the skin during infants as untreated eczema increases risks in many ways > scratching resulting in infection, dry and ‘porous’ skin to more opportunities for sensitization. Extract from WorldAllergy.org below:
From WorldAllergy.org
Atopic March is frequently misunderstood as the development from minor symptoms over a mild disease expression towards more severe chronic manifestations. It also has been misinterpreted as the exclusive development from atopic dermatitis in infancy to airway disease, particularly asthma in school-age. These interpretations have been shown to underestimate the variations and heterogeneity of atopy development during the first decade of life.
References:
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Clausen, ML., Agner, T. & Thomsen, S.F. Curr Treat Options Allergy (2015) 2: 218. doi:10.1007/s40521-015-0056-y
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Zheng T, Yu J, Oh MH, Zhu Z. The Atopic March: Progression from Atopic Dermatitis to Allergic Rhinitis and Asthma. Allergy Asthma Immunol Res. 2011 Apr;3(2):67-73. https://doi.org/10.4168/aair.2011.3.2.67
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Increasing Comorbidities Suggest that Atopic Dermatitis Is a Systemic Disorder Brunner, Patrick M.Bagot, Martine et al. Journal of Investigative Dermatology , Volume 137 , Issue 1 , 18 – 25
