Robert Sidbury, MD, MPH, chief of the Division of Dermatology at Seattle Children's Hospital, discusses risk factors involved in the pathogenesis of atopic dermatitis and several diagnostic methods.
A family history of atopic disease serves as a major risk factor for the development of atopic dermatitis, while diagnostic methods of skin biopsy and patch testing are used if clinical diagnosis is in question, said Robert Sidbury, MD, MPH, chief of the Division of Dermatology at Seattle Children's Hospital.
Can you speak on some common risk factors involved in the pathogenesis of atopic dermatitis and current diagnostic methods in younger and older populations?
Risk factors for atopic dermatitis—classically one of the first questions that we ask all patients, but in particular when atopic dermatitis is at question—is whether there's a family history.
That's not just a family history of atopic dermatitis or eczema—I'll use those 2 terms synonymously for the purpose of this interview—not just a family history of eczema, but also a family history of asthma, family history of food allergies, family history of allergic rhinitis or hay fever. So, that sort of flavor, that so-called atopic history is a significant risk factor for atopic dermatitis, and really the first thing that we ask.
In terms of diagnostic methods, the diagnosis of atopic dermatitis or eczema is typically a clinical one. We don't typically do a skin biopsy, we don't typically do bloodwork, though, both of those modalities can be supportive if the diagnosis is in question. You'd expect to see spongiosis in the biopsy that might support a diagnosis of atopic dermatitis if you were, for instance, trying to discriminate it from psoriasis.
You might see elevated blood markers, including IgE [Immunoglobulin E], eosinophils, other things like that that are not specific, by a long stretch for atopic dermatitis, but might be supportive of the diagnosis.
In terms of actual other diagnostic procedures when you're trying to separate atopic dermatitis from other things, one thing that comes up fairly often is allergic contact dermatitis. It is seen more frequently in patients with atopic dermatitis so there's a lot of overlap. You do a skin biopsy and the findings are identical.
So, that's a place where the markers we've talked about before, the biopsy results are not going to help you. So, then there's a type of allergy testing called patch testing, which can be extraordinarily helpful in patients with atopic dermatitis where you're trying to rule out a contact allergy. So, there are certain tests that we do, though by and large, the diagnosis is a clinical one.