Atopic Dermatitis: Pathophysiology Driving Management Decisions - Episode 2

The Prevalence of Atopic Dermatitis

Emma Guttman, MD, PhD, reviews the prevalence of atopic dermatitis, the percentage of patients who outgrow their eczema, and risk factors.

Peter A. Lio, MD: That’s a perfect segue to the next question, which is this: if it’s not certain that it’s 1 disease or there may be subtypes or endotypes within it, how do we measure the prevalence of atopic dermatitis? How do we estimate the prevalence, for example, in pediatrics, adolescents, and even in adult populations? Emma, what are your thoughts on that?

Emma Guttman, MD, PhD: Luckily, we recently had some good publications. We now know that in the United States, and there were some independent studies that came with the same numbers, we are talking about 7% of the adults in the United States having atopic dermatitis, so it’s a large portion of adults. These are all patients, with mild, moderate, and severe cases, but we know that approximately 20% to 30% will have moderate to severe disease, and of course the majority have milder disease. In children, it seems that it occurs in 15% in the United States, and it can get as high as 25% in Asia for children.

Peter A. Lio, MD: We hear a lot about children outgrowing their atopic dermatitis. What are your thoughts on that? There have been many times when my patients have told me that they are upset because they’ve been told over and over not to worry and that they’ll grow out of it. Here they are, 2, 4, and even 10 years on, that they still continue to suffer from atopic dermatitis.

Emma Guttman, MD, PhD: That’s an excellent question. We do see adults who supposedly outgrew the disease when they were children, yet it came back later in adulthood. This is a bit of a myth because a parent and children are told, “You will certainly outgrow eczema by the time you are 10 years old.” Then they are 12 and 13 years old, and they don’t understand why they never outgrew it. Here is the importance of treating early in the game to allow them to outgrow the eczema and to prevent other comorbidities that are associated and develop later, such as asthma.

Peter A. Lio, MD: Do you feel that there are specific risk factors or clinical features that can help us predict if someone is more likely to continue on more chronically, or if they may be in the lucky group of more self-limited patients? Do we not have that technology yet.

Emma Guttman, MD, PhD: We don’t yet have that knowledge or technology, but patients with more severe disease are probably those who are more likely to not outgrow it if we don’t help. When I say more severe disease, I mean eczema that affects a larger percentage of body surface area with weeping lesions that are severely affecting their life. For these patients, I don’t see how applying topical agents will miraculously make them outgrow it. These patients will likely need some systemic medications.

Peter A. Lio, MD: I like that. I like that you put a hint in there that, if we treat it, we may prevent it from continuing. You suggested that a bit. Do you think there’s something to that?

Emma Guttman, MD, PhD: Absolutely. In children who already have moderate to severe disease, we’ve shown that it’s systemic. We have molecules in the blood, and there are sources in the skin. You don’t have systemic immune activation that affects the seemingly normal skin; the nonlesional skin is not normal. How are you going to treat it topically? You have to put some systemic medication on board to control the disease and help the patient potentially outgrow it.

Peter A. Lio, MD: Linda, have you seen patients in your experience who have gone into a remission where you’ve gotten it under such good control such that it seems like you can let go of some of the treatments and the patient will stay relatively improved?

Linda Stein Gold, MD: I have seen that. I see that quite often, and I don’t know if it’s because they’re outgrowing it and their time is finished, or if the progress of the disease was modified.

Peter A. Lio, MD: I’m hopeful that we can modify the disease progression and that it is a disease of the vicious cycle. If we get them tamed, then we become virtuous cycles, and then things can heal.