A is for Atopic Dermatitis

Atopic Dermatitis or Atopic Eczema

An A that is as confused as our nomenclature

Well, the first step of recovery is acknowledging the problem. Borrowing from Alcoholics Anonymous, their 1st of the 12 steps is We admitted we were powerless over alcohol – that our lives had become unmanageable.

In our case, it is difficult to fully acknowledge the problem when we don’t know what the problem is. The irony is that there is difficulty defining the problem – in fact, the very term “atopic dermatitis” seems to be somewhat a matter of contention.

Mostly, we understand atopic dermatitis to refer to a chronic skin condition characterized by itch (pruritus), dry skin and inflammation, which waxes and wanes (with flare-ups). It is a multi-factorial condition, with causes and triggers linked to autoimmune and genetic factors, defective skin barrier, staph aureus bacteria colonization and hypersensitivity to allergens (including environmental ones like inhaled allergens, food allergens and contact allergens).

The difficulty is that there are many forms of dermatitis, and there are overlaps in symptoms and treatment. Broadly speaking, we want a way to differentiate whether we get the skin inflammation/ rashes because it is linked to immunoglobulin E (IgE) (antibodies produced by the immune system which defend the body but our immune system can wrongly recognize harmless substances as something to fight against, thus leading to allergic reaction). For instance, there are other forms of dermatitis where IgE is not involved, notably irritant contact dermatitis (where your skin develops rashes because it is in contact with a substance over a prolonged period).

There was an article published1 in European Journal of Allergy and Clinical Immunology in August 2016 which suggested the use of the term atopic dermatitis in literature, to differentiate from eczema which is commonly used to cover all forms of inflammatory rashes. Quoting from the article that reviews the existing literature:

Atopic dermatitis is the most commonly used term and appears to be increasing in popularity. Given that eczema is a nonspecific term that describes the morphological appearance of several forms of dermatitis, we strongly suggest the use of a more specific term, AD, in publications, healthcare clinician training, and patient education.

On the other hand, another article2 published in the Acta Dermatovenerol Croat highlighted that the Nomenclature Review Committee Of The World Allergy Organization recommended the term “eczema”. As extracted from World Allergy Organization website,

The umbrella term for a local inflammation of the skin should be dermatitis. What is generally known as “atopic eczema/dermatitis” is not one, single disease but rather an aggregation of several diseases with certain characteristics in common. A more appropriate term is eczema.

…eczema in a person of the atopic constitution, should be called atopic eczema.

The non-allergic variety can also be described by terms like irritant/toxic contact dermatitis.

I wonder why it seemed to be difficult to agree on whether it ought to be atopic dermatitis or atopic eczema, but inserting atopic does help to clarify that the skin condition should be rooted in IgE. Atopy as defined by the World Allergy Organization is:

Atopy is a personal and/or familial tendency, usually in childhood or adolescence, to become sensitized and produce IgE antibodies in response to ordinary exposure to allergens, usually proteins. As a consequence, such individuals can develop typical symptoms of asthma, rhinoconjunctivitis, or eczema. The terms ‘atopy’ and ‘atopic’ should be reserved to describe the genetic predisposition to become IgE-sensitized to allergens commonly occurring in the environment and to which everyone is exposed but to which the majority do not produce a prolonged IgE antibody response.

The “good news” is no matter what you call it, the way to treat it is the same – finding out the triggers, avoidance, moisturizing, steroidal and non-steroidal options, and lifestyle changes to reduce inflammation and staph bacteria colonization. The bad news is we will continue to wonder at the back of our mind whether we are contributing to misleading literature if we fail to clearly define what we’re writing about – well, at least for an eczema/ atopic dermatitis blogger like me, I certainly struggle. A cartoon for it:

Atopic dermatitis or man? Both are as confused!

Atopic dermatitis or man? Both are as confused!

References:

  1. Kantor R, Thyssen JP, Paller AS, Silverberg JI. Atopic dermatitis, atopic eczema, or eczema? A systematic review, meta-analysis, and recommendation for uniform use of ‘atopic dermatitis’. Allergy 2016; 71: 1480–1485.

  2. Zbigniew Samochocki, Rożalski M, Rudnicka L, Atopic and Non-atopic Eczema. Acta Dermatovenerol Croat 2016 Jun;24(2):110-5.

Eczema Blues