So far we have not gone ‘technical’ in this blog to differentiate between atopic dermatitis and contact dermatitis, simply because when we talk about eczema, we are referring to atopic dermatitis. So what’s the difference between the two? And more importantly, are our eczema children also suffering from contact dermatitis? Is the treatment the same? And are they more likely to have contact dermatitis when older?
Phew, this already sounds like a stressful topic (everything is stressful the minute I think about anything from primary school/ grade school onwards!) These topics will be broken into two manageable reading posts, with a focus to share about the research on relationship between atopic and contact dermatitis (at least what I can find from past 3 years!)
What is Contact Dermatitis?
To complicate matters, there are two types of contact dermatitis – allergic and irritant. Allergic contact dermatitis involves the immune system by which a hypersensitive reaction (rash) results from a previous contact with the allergen. Irritant contact dermatitis, on the other hand, does not involve the immune system being sensitized to the irritant. It is a delayed hypersensitive reaction due to prolonged exposure to the irritant.
How is it different from Atopic Dermatitis?
Irritant contact dermatitis is different from atopic dermatitis in that usually more than a minuscule amount of the irritant is required to generate the hypersensitive reaction, whereas in atopic dermatitis, a very small amount can cause a severe flare-up. The mechanism of which the rashes appear differ – contact dermatitis is known as type IV delayed hypersensitivity reaction which does not involve the (IgE) immune system whereas atopic dermatitis is type 1 IgE-mediated reaction.
Which one is my Child suffering from?
This can be difficult to figure out because the symptoms of eczema and contact dermatitis are similar, such as red rashes, blisters, thickening of skin (lichenification), scaly skin and itch.
Atopic dermatitis (eczema) is more common in children, however when the child does not respond to treatment, it may be worthwhile exploring if he/she is having rashes from the chemicals the skin comes into contact with. The relationship and prevalence of the two is still not super clear, as it may be due to the much higher amount of lotions and medication used on the eczema child’s skin. This study suggest that there is increasing prevalence of contact dermatitis in children, whereas previously thought to be uncommon. Patients with atopic dermatitis are more likely to be sensitive to quaternium-15, imidazolidinyl urea, DMDM hydantoin, and 2-bromo-2-nitropropane-1,3-diol in this study.
Check back next week on Wednesday to learn of the treatment and prevention of contact dermatitis in children.