Scientific Advancements in Atopic Dermatitis with Matthew Zirwas, MD

This week Matthew Zirwas, MD, a board-certified dermatologist based at DOCS Dermatology in Columbus, Ohio, presented on contact dermatitis, atopic dermatitis (AD), and recent literature at the Maui Derm NP+PA Fall meeting in Nashville, Tennessee.

Zirwas spoke with Dermatology Times on his AD presentation, including pearls on recent scientific advancements made within the disease state, environmental and dietary influences, and some simple therapies patients can use to treat their condition.

Transcript

Matthew Zirwas: Hi, I'm Dr. Matthew Zirwas. I'm a dermatologist who practices in Columbus, Ohio and part of DOCS Dermatology. In my AD session here at Maui Derm, we really talked about 2 big things. Two big buckets, the first that we'll get to moment is the new drugsand new information about the old drugs and all of that. It’ssoexciting that we're so good at treating AD. What is getting lost? The scientific advances we've made in understanding the causes of AD in the last 2 years are bigger than the understandings we gained in the 100 years before that. It has been unbelievable, and people aren't talking about it just because the drugs are so good and so exciting and so much fun to talk about. Well, I'm going to tell you about them! We understand now for the first time, why did AD start getting more common in the mid 1970s. We understand why AD is more common and probably more severe in urban areas compared to rural areas. There were all kinds of hypotheses for years. None of them held any water. The biggest was the hygiene hypothesis that kids aren't getting exposed to the outdoors and dirt and animals, that has been thoroughly debunked. We knew that it wasn't that, but we didn't know what it was. Well, turns out that the big driving factors that have been identified so far are 2 chemicals, toluene diisocyanate and xylene. Now these are 2 chemicals that are present in the environment from industrial pollution at very low levels, but the most important source is car exhaust, and in particular, car exhaust from cars that have a catalytic converter. Now why is that so interesting and important? Because when did catalytic converters go on cars? 1970s.When did AD start getting more common? 1970s. What's different between the city and the country? How many cars there are.It's even been shown now, if you live in the country, but you live near a busy road, your risk of AD goes up as if you lived in a city. We know that it's cars. We now understand why it became more common in the mid 1970s. The other place that's really interesting for those 2 chemicals, nylon and polyester. When you think about the 1970s, what kind of clothes do you think about? Polyester and nylon. Polyester and nylon also have residual toluene diisocyanate and xylene in them, and that explains what we've known forever.It really matters what our AD patients wear. They should be wearing cotton and natural fibers. Polyester and nylon make them itchier. We didn't know why, we thought maybe it was that the polyester and nylon aren't absorbing the sweat. Maybe it’s that the polyester and nylon don't breathe as well.Now we know it's this residual toluene diisocyanate and xylene that's in the clothes, which have really 3 mechanisms of causing AD.The first, in an acute and immediate sense, they activate the TRPA receptor that immediately causes itch and inflammation. That's why, whenever you wear those clothes, these people get itchy right away. Second mechanism is subacute. It affects the cutaneous microbiome. Your cutaneous microbiome is supposed to be making ceramide precursors, when the microbiome gets exposed to these chemicals it stops making the ceramide precursors, and you get an acquired ceramide deficiency. Third, the long-term chronicity, these chemicals are causing epigenetic changes in both our skin and our immune system. Then if you get away from them to a significant extent, the epigenetic damage is already done. Once you start to have eczema, the cat's out of the bag. It still helps to get away from them, but you can't cure it by getting away from them. The other place that we've now figured out is huge is diet. As derms, we hated it when our patients would ask about diet, because we knew that food allergy wasn't playing the role, and so we thought, “Probably not diet. It's a coincidence. You didn't really flare from eating that,” but patients didn't buy it. And turns out patients were right! We now know that what's really happening with diet and AD is the modern American diet induces changes in the intestinal microbiome. Those changes in the intestinal microbiome mean that your microbiome is not producing short chain fatty acids or end all metabolites, both of which are immunoregulatory and anti-inflammatory. So, let me bring all this home on why it's clinically useful. Patients ask “Why did I get this eczema? I didn't change my diet, I didn't change my products, I didn't move, I didn't change my job.” We used to say, “You got old. Your skin's old, I don't know.” I want to tell everybody, you use your hand every time you have this conversation. If I'm talking to a kid, parents of a little kid, your child was supposed to be born with skin that looked like this, and nothing could get in and irritate their skin. Well, genetically, your child's skin looks like this, and so things are getting in and they are causing this inflammation and rash. If I'm talking to an adult, when you were born, your skin looked like this. It's been damaged by the chemicals in your environment over the last 30 to 40, years. It's not that you changed something last year, it's that this damage has been slowly accumulating, and last year, the gaps got big enough that now stuff can get in and cause this rash now. First, that's just super helpful to have those explanations, because patients get it and feel like they have an answer. Then, I put everybody on an oral supplement, so phytoceramides. You get these on Amazon, the one that I like, I have no financial connection, company called Life Extension makes a skin restoring ceramide. We've got randomized, double-blind, placebo-controlled trials that show it improves barrier function. I describe it to patients: You're going to take that supplement to fill in these gaps. Then my next thing is to say, “Have you noticed food makes your AD worse?” Because about two-thirds of my patients say that it does. It's really interesting, it turns out it's not from a food allergy.It's from food affecting the natural, healthy bacteria in your intestines. You can't get your eczema better by avoiding any particular foods, but you can help make it better by taking a probiotic. We have randomized, double blind, placebo-controlled trials proving that probiotics help. In particular, the probiotic that I recommend is on Amazon, no financial connection with Amazon, or the probiotic that is on Amazon. It's from a company called now probiotic 10. It has the exact strains that have been shown randomized, double-blind, placebo-controlled trials to help with AD. Because the real thing is there are other trials with other probiotics showing they don't help withAD, so it's got to be the right probiotic. That's kind of the 10,000-foot overview of what's new, and kind of the science of AD.

[Transcript has been edited for clarity.]

In a second interview with Dermatology Times, Zirwas discussed the niches to all atopic dermatitis therapies in order to make the best decision with your patient.

To explore more of our coverage from Maui Derm NP+PA Fall 2024, click here.