An Overview of Atopic Dermatitis

Elaine Siegfried, MD: Are the terms atopic dermatitis and eczema interchangeable? They are, they are synonyms, except for atopic dermatitis is a very specific kind of eczema. Eczema and dermatitis are synonyms and there’s many different kinds of eczema, and atopic dermatitis is the most common chronic one and has its onset in childhood.

In 80% of kids, age of onset is under age 2. There is a small subset that are said to have atopic dermatitis that’s adult onset, that’s a little bit controversial. Because the disease is a clinical disease, it’s diagnosed clinically based on a set of clinical criteria. There’s no biomarkers or blood tests that you can do. And because many eczemas share different clinical features, you have to make the diagnosis just based on age of onset, what the distribution is, and what the associated symptoms are, which is horrible, intractable itch.

I’m a pediatric dermatologist. I used to see adults but I don’t see adults any more, and I don’t have recent experience with treating adults with atopic dermatitis. But there are some unique things to treating children with atopic dermatitis, and because children are the biggest bulk of the population that suffer from this disease, there are unique challenges for treating children that’s different than for adults.

We don’t have great data on how many kids outgrow the disease, that’s hard data to get. One of the fallacies I think in treating children who have atopic dermatitis by primary care providers is that they often are told that they’re going to outgrow the disease. And it’s true, while a subset does, it’s probably the minority that does. And mostly children who have really mild disease. But a good percentage of kids not only don’t outgrow it, but they go on to develop other comorbidities, atopic comorbidities we call that, so asthma and hay fever, and allergic conjunctivitis, and eosinophilic gut disease.

It’s the dawn of the decade of eczema, and with that, we have new interests and new investments in finding better treatments for the disease. It was a huge economic burden, a healthcare burden for the population in all developed countries. But now that we have that kind of attention, we have a little bit more information about that. And we know that the great majority of children who have eczema based on coding data, claims data analysis, we know that the great majority are taken care of by primary care providers. Lots of those are nurse practitioners and family practice doctors, and even to a lesser extent, pediatricians, and then a very small percentage ever make their way to dermatologists or allergists.

The prevalence of atopic dermatitis is estimated to be from 10% to 20%. Most people are using the figures from 13% to 15% in the United States.

We don’t know what the percentage of children is who have moderate or severe disease. And even to distinguish between moderate and severe, it’s just a descriptive term. The way this disease affects people is different from person to person. And I frequently say, atopic dermatitis isn’t a disease that kills you, it just ruins your life. And so it can ruin your life if you have moderate disease or it can ruin your life if you have severe disease. But if you have to peg down on a figure, and again, we don’t have the best figure for that, it’s probably of the 15% of children in this country who have atopic dermatitis, maybe 1% or 2% of those have moderate or severe disease, and that’s still a pretty big number.

Now we have investment in the disease, and there have always been lots of studies, but more on a shoestring and not quite so united. And now that there is increased interest in investment in the disease we’re having way more studies that are being done looking at the epidemiology and the pathophysiology, and the impact on people’s lives.