Are these climates or US states increasing your risk for eczema?

(Please note that the timestamp starts when the actual interview with the guest begins).

 

Abby: ([00:01])

Today. I have a really great guest for you on the show today. And I’m really honored to have him here because he’s written a lot of research papers. He told me that he’s written 200 research papers on atopic dermatitis and he also loves to study this topic. He’s a medical doctor. He has a PhD. He’s also the director of clinical research and the director of patch testing and an associate professor of the department of dermatology at the George Washington University School of Medicine. So I just want to welcome to the show today, Dr. Jonathan Silverberg. Hi John.

 

Dr. Silverberg: ([01:07])

Hi there. Thanks for having me.

 

Abby: ([01:09])

No problem. It’s such a pleasure to have you on the show. And, you know, before you came on, we were just talking about how, Jonathan was just mentioning to me that he was actually neighbors with, Dr. Peter Lio who’s been on the show before. And so it’s really great that, you know, that you guys know each other and it’s just also really, really amazing that, you’ve written all these research papers and that you have such a passion for this topic. And I find that it’s so rare to find. So thank you for all that you do in this area. And I would… I would love to know more about your story. How did you get into becoming a dermatologist and what made you so passionate about studying, atopic dermatitis in particular?

 

Dr. Silverberg: ([01:58])

Sure. So, probably a combination of a few things. I was in the right place at the right time. Great mentorship and great teachers and a little bit of my own personal story with eczema. So I actually had really bad eczema as a kid and, my, I don’t remember it that well, but my parents tell me that the doctor said it was some of the worst eczema they had ever seen. And I had outgrown it later in childhood. And ironically, it actually came back, most when I went back to Chicago to study, you know, to, to do research and treat patients with atopic dermatitis. But for me, what really led me down that career path was that I did my PhD in immunology and I’d worked very closely with allergists, who were interested in studying allergic disease. And so I started thinking about atopic dermatitis more from the allergy side of things, even though now we know it’s not quite the same as asthma or hay fever or food allergy in that sense.

 

Dr. Silverberg: ([02:57])

And so I started to do some research and during my masters of public health, I wanted to study and at the time what I thought of as that allergic disease that was common and a really understudied area. And so I came to atopic dermatitis more from, you know, from the research part of things, as sort of a sample of convenience. And I just became totally fascinated by it. I mean, it’s just such an intriguing disorder and so little known despite being so common and so burdensome. So that’s sort of what led me down that direction. And dermatology, I… I grew to love sort of independently, but it kind of all came together. I, you know, had great mentorship pushing me towards that, you know, the… The interest in atopic dermatitis and, and then a great mentorship to teach me about how to do patch testing and understand skin allergies and it kind of all came together.

 

Abby: ([03:52])

That’s amazing. That’s so great that you know, you have such a big interest in it and it brought you to this place and I’m sure that you’ve helped so many people with eczema. So we really appreciate that from you. And one of your research papers really caught my eye that I would love to talk about and focus on today. And it was one of your research papers done a couple of years ago. It was titled the prevalence of allergic disease in foreign born… Foreign born American children. And what was so interesting about this paper is that it studied the association between children who are born outside of the United States, how they had lower odds of atopic dermatitis. And then when they moved to the US the, the prevalence of getting atopic dermatitis increased after they stayed in the United States for one decade.

 

Dr. Silverberg: ([04:49])

Yeah. So this is, actually something that was, the idea of why we studied this, was really sparked by several clinical encounters at the time. I was in New York city doing a… We’re sort of finishing up my training on the clinical side of things with dermatology and just kept getting case after case of patients who would say to me, you know, when I’m in the Caribbean, my eczema is great. Right? Patients who may have been Afro Caribbean who came from the Caribbean islands and you know, it’s a much milder climate there. It’s much warmer sunnier. And you know, my eczema is clear and I, you know, I’d never had eczema as a child, but I came to the US I moved to Brooklyn and then boom, within six months, not only do I have eczema, but a really bad case.

 

Dr. Silverberg: ([05:40])

I go back to the Caribbean and everything’s great again. And I come back to Brooklyn and it all, you know, starts over again. So, you know, you see it once you think, “Oh, maybe it’s a coincidence”. When you start seeing it dozens of times, you realize there’s obviously something here. And so he said, well, if that’s the case, then you know, there’s likely going to be this phenomenon that really seen on the population level. And um, and so we looked at, um, at us population-based cohorts, really that… that have, you know, well, very well sampled studies run by the centers for disease control in the United States. And this particular study is called the national survey of children’s health. And this one, samples almost 100,000 households for children across all 50 States and patient or caregivers of those children were asked, you know, does the child have eczema?

 

Dr. Silverberg: ([06:33])

Yes or no? Were they diagnosed with eczema? But then we were able to tie that back to where the child was born and found that those who were born outside the United States actually had a lower odds, a lower rate of eczema compared to those who are born in the United States. But what was fascinating about it was that we were also able to see how many years prior they had moved to the and relocate it to the United States. And as you mentioned, those who relocated within the previous few years had the bat the same risk and nothing really changed. But by the time they were in the States for about 10 years, their risk really started to catch up to the levels of those who were born in the United States and grew up here all their life. And that is really a fascinating finding for a lot of reasons because when, you know, one of the concepts behind why many believe there are higher rates of eczema in developed countries, is because that there may be, we may be too clean, right?

 

Dr. Silverberg: ([07:37])

This idea of the hygiene hypothesis that you know, when you’re exposed to dirt and to germs early in life, it may really wire your immune system in a protective way to that. You shouldn’t develop allergies, or eczema, or asthma and things like that. And that sort of idea was that if you got exposed to dirt early in life, you’d be protected forever. And this study suggests that, well, maybe there is a protective effect of being born outside these Western areas and growing up early in life outside those westernized areas or industrialized areas where they’re there, whatever the reasons are. But once you get to the United States, once you’re exposed to these new exposures later in life, eventually your risk starts to climb. And so, and to me it’s actually something that is tied together with another finding from another study that we’ve done later where we looked at the characteristics of a adult onset atopic dermatitis, which is a very, that is a controversial area.

 

Dr. Silverberg: ([08:39])

I mean there it’s a hard thing to diagnose and you want to make sure you’re not missing other diagnoses. But I’m a firm believer that there is truly an entity of atopic dermatitis that can first begin or recur and adulthood. And you know, based on the findings, the study we were talking about before, when I said to myself, well, if it takes 10 years after moving to the United States to start catching up in the risk, well that would mean that their presentation is much later. They’re not developing their eczema as an infant, as we’re always told that eczema is always a childhood disease. In fact, these are folks who are going to develop and lead into adolescence or even first and adults. So we looked at the characteristics of our adult onset eczema patients and found that not surprisingly, one of the risk factors for later onset eczema were those who were born outside the United States.

 

Dr. Silverberg: ([09:30])

And it’s interesting because many of them even had asthma or hay fever as children, but they were living in an area with a much more temperate climate, patients coming from Southeast Asia where they’re, it’s not that cold dry climate that you get in Chicago. And, but once they came to the US all of a sudden the risk, you know, they started to present with these skin symptoms as well. And so I think it’s really, it ties together to a broader, relationship between the atopic dermatitis and obviously, you know, climate environmental factors. But it’s really fascinating that there are these… there seem to be these early life protective factors that may you know, reduce the risk of atopic dermatitis. And conversely, there are things that are going to be risk factors in an, in an, you know, metropolitan living, um, urbanized areas and things like that.

 

Abby: ([10:26])

That’s really, really interesting. And I think I saw that the New York times also quoted your research paper and I think what they quoted was that there was actually like a 48% increase in risk after they moved to the States. And I just found that really that’s a huge number.

 

Dr. Silverberg: ([10:43])

It is. It is. And look, it doesn’t mean that everyone moving to the US is going to get eczema. But what it does say is that if there’s someone who has high risk, someone who may have other allergic diseases, maybe has a family history of atopic dermatitis, but is living in perhaps a climate or an a region where the environment is really protective or conducive to not getting eczema a change in the environment can actually be quite harmful. And yes, you can have this really considerable increase in risk, for the atopic dermatitis later on. But it’s true. I mean, to have this kind of reduction by almost 50%, you know, to have of getting a atopic dermatitis. I mean, it’s, it’s a substantial number. It’s not just, you know, 5% reduction. That’s a big number in the world of epidemiology. And it really just shows you what a protective effect that can have.

 

Dr. Silverberg: ([11:33])

I will also say some, you know, some folks who, who follow this line of research may suggest that, well, maybe it’s just because the folks who are first moving to the United States, maybe they just don’t have access to health care as much. You know, maybe they’re new immigrants to the country. Maybe they don’t have health insurance, they don’t have access to a specialist, but we actually controlled for that in the study. And we found that independent of that issue, there’s still this seemingly protective effect of being born outside the United States. And you know, we weren’t the first study to show this as well. There are other studies that were done in Australia that were published also in England that showed similar phenomenon that folks who were, born outside those countries and then came later in life to those countries, ended up developing a increased risk of eczema and developing eczema later in life. And there’s a lot of similarities and overlap in terms of the, the environment and the climate and the Lucian and urban exposures that one gets in many areas in the US, similar to what might one might experience in England and many other areas that are sort of colder driver climates.

 

Abby: ([12:45])

That’s very, very fascinating. Did they, uh, did the research also explain, um, other reasons why it might have increased? Is it because maybe like the, you know, the type of food found in the States versus their home area, maybe like fast food and things like that.

 

Dr. Silverberg: ([13:02])

Absolutely. You know, this is the challenge we faced with this kind of big population-based research is we can describe really those very big picture phenomenon. What’s hard to know is exactly the reason why, and I don’t think it’s just one reason I think it’s going to be multifactorial. I think part of it is going to be climate issues. We’ve seen this anecdotally, and, and their follow up studies, we’ve seen differences in terms of from which regions patients may be migrating from, coming from warmer climates, nicer areas weather-wise seems to have an even more protective effect than if somebody is coming from, you know, really far North or an areas where there’s just very little sun exposure and very dry cold climate. But there’s definitely more than that because, folks who grow up in rural areas, and that would be true even in the United States, but there’s multiple studies that have shown protective effects of growing up on a farm or the equivalent of a farm. You know, one of the most protective things early in life would actually be to, I mean, it sounds like a joke, but to live on a farm and roll around in, in manure and I wouldn’t recommend that for all patients

 

Dr. Silverberg: ([14:15])

but, but it’s something that, those, that’s part of that hygiene hypothesis, the idea that those early life exposures to dirt, to microbes, to things like that where when you’re in an urban environment, you know, everything is gone. You don’t have those exposures as much and so you lose that protective effect as well. But yes, I think diet is an important one. And the issue with died is it’s so complex and it’s so hard to study from a research standpoint, but there are clearly very different diets that occur in different parts of the world. And there are some studies that have shown that Western diet in general is actually a risk factor for getting more eczema. And that was actually a study that was done from the international study of allergy and asthma in children. The AIESEC study, uh, that found this association between Western diet and higher rates of multiple allergic diseases, but including atopic dermatitis.

 

Dr. Silverberg: ([15:09])

And it’s not clear why it really is it possible that it’s not the food and it’s maybe because the folks who are eating Western diet happened to live in more urban areas, maybe. But those studies really did try to control for that. There’s something in what we eat that seems to contribute and it, and it’s probably not just as simple as saying, Oh, it’s a food allergy. I think it’s more complex than that. There are certain foods that are more proinflammatory that tend to set off the immune system a little bit more. But it’s very early in this line of research. So we really don’t understand what specific foods may be harmful, may not be harmful. But I have a feeling the folks who are coming from outside the United States who are eating less processed foods, cleaner diets, more balanced diets, that’s probably one of the reasons why they have a little bit of lower rates of eczema.

 

Abby: ([16:02])

I would also love to expand more on the, what you mentioned about  when people move from warmer climates to the States, they seem to do better than moving from colder climates. And I would love to know more about why this might be the reason.

 

Dr. Silverberg: ([16:19])

Yeah. So there’s, there’s actually a number of studies that have looked at this and we published this study a few years back, about four or five years ago in journal of investigative dermatology that looked at the relationship between various climate factors and just the prevalence. You know, how common a atopic dermatitis is in children in the United States. And what we found was that children who lived in States that have higher sun exposure, higher humidity  and higher temperature, all were, had better protection, have lower rates of eczema compared to those who were living, let’s say in a Chicago where you’re farther from the equator. So you’re getting less ultraviolet exposure. You’re, you know, it’s cold and dry much of the year. And, uh, and that seems to be a risk back. Now, the question is why. And there’s probably a few reasons. So with ultraviolet light, um, that is something that in moderation can actually be very helpful for eczema.

 

Dr. Silverberg: ([17:22])

And in fact, one of the treatments that is used really globally is ultraviolet therapy or phototherapy as a treatment for atopic dermatitis. And there’s different forms that are used around the world. Well, in fact, just getting some natural, if some exposure will accomplish the same effect. And so in folks who live outdoors or who live in areas that are warmer, less precipitation, they’re able to go outdoors more, spend more outside time, get more natural sun exposure, that sun exposure, the ultraviolet exposure has a, what we call a photo immunosuppressing effect. The light itself actually kills off the immune cells in our skin that are causing us to be itchy and inflamed. But it doesn’t mess with our immune system internally. So it’s something that we see as a benefit. Of course, as a dermatologist, I always have to throw the disclaimer in there, be very careful not to overdo the sun exposure, right?

 

Dr. Silverberg: ([18:14])

Because we don’t want to get increased skin cancer risk. But that’s a separate, you know, concern. But humidity also is an important factor because this is skin of eczema is dry to begin with. And now if you put it  in an a region or an environment that is bone dry, that is going to really make the skin even more vulnerable to getting inflamed, itchy, or et cetera. So one of the things that that is often recommended by clinicians is to use things like indoor humidifiers to try to offset some of that indoor dryness when there’s a, you know, when it’s very dry and cold out. So I think there’s a lot of factors that tie together, but folks who live in areas where it’s naturally quite warm, they’re spending more time outdoors, getting more natural sun exposure. They’re not facing the issues of intense dryness because there’s more natural humanity.

 

Dr. Silverberg: ([19:05])

All of that can be very good for the skin. Of course, all of this is in moderation. Like everything else in life, you know, the best option is moderation because even living in regions where it tends to be more humid, well that’s good during the temper times of year, but when it gets to the, you know, the hottest times of the summer, well then the heat and humidity can be so bad that even that can flare up eczema as well. And so there’s often this thought that the only environmental factor that’s a problem for eczema is cold and dryness. And that’s a big one. But actually it turns out in many parts of the world, the most common trigger is actually heat and sweat. So, you know, there’s a fine balance between, you know, getting enough humidity so that your skin is not dry or less dry, but not getting too much humidity that now you’re just super itchy and uncomfortable.

 

Abby: ([19:55])

That’s a, that’s a fine balance. That’s a bit tough to tough to balance out. But yeah, so that’s very interesting. So you sit in heat and sweat, actually triggers more flare ups instead of the cold temperature during the winters.

 

Dr. Silverberg: ([20:13])

Yeah. So there, there’s actually a few studies that have looked at this, in both children and adults. Like what are the most common triggers for atopic dermatitis and it turns out in some of the studies, heat and sweat were actually more common triggers than cold and dryness was, I think some of this has to, you know, really will vary depending on the region of where someone lives. My experience being in Chicago and being in, in the Washington DC area and in the New York area in different, you know, stages of my training was that those were areas that generally we’re very cold during the winter and relatively mild during the, the spring and summertime. So, you know, there wasn’t such an extreme heat and, and you know, sweat component during the summertime that it was the most prominent concern for patients. Whereas in Chicago it is so cold for so many months of the year that that dryness is really looms large in the lives of patients with eczema.

 

Dr. Silverberg: ([21:13])

But you know, when you go to a place where they’re South in the US like a Texas or you go to a Miami where, you know, it’s just much sunnier, much warmer, much more humid, it starts to resemble a lot more of, you know, more temperate and tropical climates where in the winter time they may not flare as much. They still can flare in the winter when the indoor he comes on, but not quite as much. But in the summertime when there’s just that unbearable heat and sweat that can be a major source of flaring for patients.

 

Abby: ([21:43])

So have you found in any of your papers or research articles, um, where uh, eczema is a more prevalent and higher in areas of colder climates in the States versus areas of warmer climates in States?

 

Dr. Silverberg: ([21:59])

Yes. And then that, so that’s what I was sort of mentioning beforehand that there’s, you know, we found this association that those folks who live in the Northern regions of the United States farther away from the equator are getting less of that natural sun exposure, more cold temperatures, things like that. Though there the prevalence is of eczema is generally higher in those areas. You know, what’s fascinating when you’re, whenever you’re trying to examine the prevalence of a disease across a state or a country or city, you know, there’s a lot of things that drive prevalence and some of that is going to be the environmental factors. But you also have to keep in mind that the, you know, the population is, are very different between different regions and sometimes there are genetic factors or other populations that risk factors. But one of the fascinating exercises that I did in a follow up study was that when you control for Mmm background, demographics, race, ethnicity, gender and age, Mmm [inaudible] these multivariable models, what you find is an almost perfect gradient of, you know, North to South where the highest rates of eczema off North, once you control for all the background factors and the lowest rates are going further South as you get towards the bottom of the United States, closer to the equator.

 

Dr. Silverberg: ([23:22])

So it’s certainly not the only factor, but when you control for some of those other risk factors, you see it almost perfectly in a visual map. We actually publish that in a follow up paper as well and it was really startling to see this just this gradient happen. But, it’s generally a more protective, all things being equal to live in a, in a warmer sunnier than it is to be at a colder drier. Carmen.

 

Abby: ([23:48])

I’m going to get a lot of questions about this because a lot of people are going to ask, well, should I move from a colder climate to it?

 

Dr. Silverberg: ([23:56])

You know, you beat me to it because when I publish the study that you were mentioning earlier about how in different States, you know, the colder drier States were ones that are associated with higher rates of eczema. After that study was published, I must’ve had about 20, 30 people email me asking me, so I have really bad eczema and I live in such and such place. Where should I move? What’s the best place to move to avoid the eczema? And the problem is, it’s hard to answer that question for a couple of reasons. One obviously everyone has to make life in a pragmatic way. It’s hard to sometimes pick based only on that, but two is that when we look at prevalence and we look at how environment interacts with prevalence, what we don’t know is all right, so maybe because someone grew up in a cold, dry area, that is what sort of kicked off or started or contributed towards the development of their eczema, but now that they have eczema and especially in the case where it can be pretty bad

 

Dr. Silverberg: ([24:58])

Does moving at that point really fix anything and no one knows the answer to that question. I mean, I’ve had some individual cases where they’ve gone back and forth and we have seen some improvements. But for some of those really tough cases, I suspect that I could even, you know, they could live in a bubble and they would probably still flare because it’s now a chronic sort of auto inflammatory autoimmune disorder at that point. And so I don’t recommend moving based purely on that kind of environmental factor because we don’t really know for each individual patient how much of a difference it’ll make. Now, if someone happens to live in a cold place and they go on vacation to someplace warm and sun or like a Southern California to Hawaii and they notice that within 48 hours their eczema is like 90% better. And we have many patients who have experienced this phenomenon, well then that might be a very good place to go. But the only way you’re going to know is from firsthand experience. It’s going to be very hard to predict otherwise.

 

Abby: ([26:00])

And how much would you say that it actually, you mentioned the map before, how there’s a, the Northern area and the Southern area.  So in your research, have you found if there’s a certain percentage that is higher compared to the Southern areas?

 

Dr. Silverberg: ([26:19])

So it’s again, you know, when you actually, I’m going to need to even pull up the manuscript so I can even take a look in that manuscript. We published a few different things. So there’s the, the actual, there’s the prevalence of, so actually I should say there were a few papers that we published on this. One was looking at this exercise in atopic dermatitis. There was another that also examined,  prevalence is of hay fever as well. So seasonal allergies actually also follow a certain relationship with climate. So in the paper where we looked at the atopic dermatitis, we didn’t publish any sort of maps, visual maps. We just sort of presented those tables about areas that are the highest sort of 25 percentile or the highest core tile of humidity or hue or highest UV index and things like that.

 

Dr. Silverberg: ([27:13])

And you know, in those, in those areas that are the highest core tile, the high steel top 25%, States of humidity, uh, you have about a 20% reduction in the odds of getting eczema or having eczema. For the highest UV areas, you actually have the most sort of protective effect with an almost 30% reduction in the rate or in the rates of [inaudible]. Well, with UV or  higher temperatures as well. Some similar to the sunlight to the humidity story, which is about a 20% reduction. And then for precipitation, the opposite. So the more precipitation, right, the highest regions for precipitation actually have about a 30% increased rate of eczema. So now you sort of have to go around the country because it’s not with climate in the US it’s not quite as simple as going, you know, North to South or or South to North in that respect.

 

Dr. Silverberg: ([28:10])

But from a climate perspective, you’re talking about basically the top third of the country is going to be the coldest and dry us with the least sod. And you know, the bottom third is going to be the hottest and the warmest with the most precipitant precipitation or most humidity and least precipitation that’s keeping people indoors. And then of course there’s some in the middle is roughly in the middle. But it’s when you look at the prevalence maps about what are the States that are most common for a topic dermatitis, you actually don’t see it quite as neatly because there are other things that will drive high rates of eczema. So, for example, there’s a fascinating, association in the US that African American children have twice as the rate of eczema in childhood compared to Caucasian children.

 

Dr. Silverberg: ([29:07])

And that’s a fact. And they have more severe disease as well. And this is, this is very tricky. So, you know, I’m finding we don’t really understand all of it. This may fit because there’s racial and ethnic disparities in the US that contributes to some of this, but because of those other types of findings that, you know, the younger a child is generally the higher the rates of eczema, there’s these racial differences, there are gender differences. Well, all of that sort of gets kind of like swallowed up into the prevalence estimates across different States. So when you look at the overall prevalence map, what you’ll find is that some of the highest prevalence is, are not always in the coldest areas, but there’s some times in the areas that are the most urban, that have the most metropolitan areas that have the most racial ethnic minorities. And so because of those differences, it’s kind of hard to look at just a prevalence map and see that clear spread. But after you control for all of those factors, that’s when you see this just perfect gradients of, of North to South.

 

Abby: ([30:09])

So, were you saying that in urban areas there tends to be more prevalence as well? Maybe because of pollution or other factors?

 

Dr. Silverberg: ([30:18])

This gets right back to where we started about the foreign born children. And I think it’s a very similar story. This is one of the most well reproduced reproduced findings in, in research and atopic dermatitis epidemiology. You know, a lot of times you have studies that we’ll find something and it never gets duplicated. This finding about higher rates of eczema in metropolitan areas is been reproduced across dozens and dozens of studies across different countries, regions. I’m not sure if there’s even a single study that I’ve seen recently that has not shown that fine. And the question is why? Part of it could be, again, because you know, we’re not living on farms so we’re not getting some of those protective exposures. Part of it could be because we’re living sedentary lifestyle, we may have differences in diet, we may not be outdoors as much in getting some of that natural sun exposure we talked about earlier.

 

Dr. Silverberg: ([31:14])

So I think there’s many factors that go into this. Pollution is a fascinating one. Pollution is the one thing I can say that when I’ve done research and atopic dermatitis but one time I feel like I got schooled or, or bested by the research project wasn’t studying pollution because it is so complex. But fascinating pollution follows an almost perfect course with climate, right? There are certain small particle air pollutants that go up and down directly with temperature, with outdoor humidity, with air pressure. So you know, when we talk about different areas having problems based on climate, this component of pollution is always something in the background that we just don’t ever really know. There are many studies that have shown in Europe in particular living closer to highways where there may be more burning the tires and other and rubber allergens in the air and other irritants, exposures from auto pollution has been associated with potentially higher rates of eczema.

 

Dr. Silverberg: ([32:16])

And there’s various types of studies like this. So I think there is definitely a contributing factor or contributing role of pollution, but it’s so early and it’s so hard to study. Yeah, we don’t really know enough. And actually some of the best studies right now, um, have really been coming out of China in elucidating the role of sort of longitudinal effects of small particles, air pollution on day to day activity with eczema. Most of what we have available data-wise in the U S is more sort of big picture, not day to day, uh, from the prevalence and from the sort of the course of the atopic dermatitis. But there’s some fascinating studies that have suggested, not only is small particle air pollution, a driver of higher rates of eczema, but it may actually drive the disease course where it may drive flares or periods of remission when the pollution gets better.

 

Abby: ([33:12])

That’s so fascinating. There’s a lot of great information and I’m just loving all the information that you’re giving because it’s so new and I think that a lot of our audience hasn’t heard of it before as well. I would love for you to touch upon, you mentioned that you know, when there’s an area of high precipitation, uh, exhibit can increase by 20% as well. And I would love to know why it aggravates the skin so much.

 

Dr. Silverberg: ([33:38])

Yeah, so this is when we speculated on, I mean, again, we can’t know 100%, but you know, we have some thoughts on this. You know, on the one hand where there’s precipitation, usually there’s higher humidity. So you would think, well, if anything that should be more protective. But on the flip side where there’s a lot of precipitation, people are stuck indoors. They’re not getting outside. They’re not getting that natural sun exposure cause it’s cloudy with that cloud cover. You lo, you lose that UV. But they’re also bumbled up in rain clothing. So they’re, you know, they’re not getting that natural sun exposure.There may be more indoors and exposed to indoor pollution or, or indoor heat that may be drawing out their skin a little bit more. So there may be multiple factors that dry. This, the other thing is certain regions, where it’s very rainy, there are rainy regions that are cold and rainy and then there were rainy regions that are hot and rainy and there may be differences between those.

 

Dr. Silverberg: ([34:34])

So for example, you know, Portland, Oregon is, you know, we think of it as almost one of the capitals of atopic dermatitis in the United States. For a few reasons. One biggest, it tends to be very high rates of eczema there, but to also, because some of the leaders of the field are, are out there. And in terms of research and um, and clinical care, but that’s an example of cold and rainy. And so when it rains, it’s just cloudy all the time. It’s always raining. It’s always kind of like depressing weather and, uh, and you know, so because of that, folks are indoors more than they’d like to be. It tends to be more of an outdoorsy society there, but they’re stuck indoors because it’s cold and they can’t, you know, they can’t go out and it’s raining all the time.

 

Dr. Silverberg: ([35:20])

some of them actually even suggested that living in an area where it’s really cold and rainy just makes people feel blah and feel a little depressed and that’s gonna make the reaction of flare up a little bit more. And I think that there’s probably some contributing factor with that as well. But if you’re living in an area where it’s more hot and humid and rainy, it may have a different effect. It may not be, a risk factor as much in those areas. So that’s one of the tricky things that comes up is that climate factors never happened in isolation. They always happen together. So it’s not just there’s places of high you middle or high precipitation, they come in different sort of configurations in different parts of the world. And it’s sort of how all those add up that ultimately will impact the skin.

 

Abby: ([36:03])

That is so interesting. What about snow? Have you ever seen how that impacts the skin?

 

Dr. Silverberg: ([36:11])

Yeah, so we didn’t, we didn’t look at snow per say there. There aren’t too many studies that have looked at snow per se with atopic dermatitis. I think there are a few out of Europe that had mixed results. It’s, snow is a little tricky also because you know, there’s one inch of snow that mainland and then there’s three feet of snow that keeps someone trapped in their house for a week. And those are obviously two very different things. So even when you’re measuring that, it’s a little different than when you’re measuring precipitation in general. But you know, snow Cub or snow fall would be included in those precipitation estimates sort of lumped together. Cause sometimes the precipitation will be rain and sometimes it’ll be snow. But we don’t know about specifically effects of snow.

 

Abby: ([36:59])

That is very, very fascinating. I’m just loving all the information that you’re giving. What about, in terms of the States that you’ve found, which States have the lowest prevalence of eczema and which States tend to have the highest? I know you mentioned Northern versus Selden, but I’m just curious which actual States.

 

Dr. Silverberg: ([37:19])

Yeah, so I have to remember this off. I don’t remember this off the top of my head myself. So give me one quick second.

 

Abby: ([37:25])

Yeah, no problem. I’m probably testing you as well because I just also want to commend you on such a great memory on, especially with  the research paper you did just like so many great facts that you have for the research paper about eczema increasing 48% after children moved to the States for 10 years. That research paper was done six years ago.

 

Dr. Silverberg: ([37:52])

Yup. Yeah. So, it depends which years one looks at, but from one of the first studies that looked at the 2003, 2004, a national survey of children’s health and broke it down by state. The States that tend to be the best in that respect. There are a few. Florida’s is a good one. Texas, Tennessee generally speaking is a good one. Southern California generally tends to be a little bit better in that respect. Some of the interesting, the plain States are actually fairly good as well, despite them being relatively cold areas. And then there’s also some of the, you just sort of scattered, isolated throughout. So when you look at it at the, at the prevalence map overall, it’s a little, what’s the word? It’s a little scattered, right? It’s not just like clear cut versus when you look at severity. Actually when you look at the prevalence that probably the most common, the highest rates of eczema really found along sort of the Northeast and the Southeast corridor of the United States and, and towards the Pacific Northwest. And not entirely clear why those may be less about climate and more about, again, other risk factors, pollution, population risk factors, differences in demographics, etc.

 

Abby: ([39:16])

Do you think New York is one of them because of the highly urban area, the metropolitan area plus it’s, it can be really cold in the winter too.

 

Dr. Silverberg: ([39:25])

Yup. New. So New York, interestingly enough, New York is not the worst. But it’s definitely one of the, the higher up ones. And you know, they’re, the way the studies have looked at it is, you know, they divided up the sort of groups of three and the worst States are the red States in the sense that they have the highest prevalence of eczema. New York is one of those red States. And like I said, it’s not the worst, but New York, New Jersey, Connecticut, Massachusetts, Rhode Island, all are those high prevalence States there. But you even see it with, you know, going down the coast, in terms of Virginia, West Virginia, you know, there’s, these are areas that, you know, technically is, are starting to get much warmer as you move further South down the East coast and still you see fairly high prevalence. Even Georgia is one of those that has a fairly high prevalence. But again, some of that may not be the climate issue. Some of that may be the fact that these have more urban areas, larger proportions of African American children who have that higher risk to begin with. So, you know, there’s a little complexity to it.

 

Abby: ([40:37])

Do you think you’d send me the map after? I would love to link to it and go people, cause I know I’m going to get so many questions for people who are, want to see the map.

 

Dr. Silverberg: ([40:50])

Sure. Yeah, absolutely.

 

Abby: ([40:51])

That is so wonderful. I know that we’re running low on time and I know you have to go soon, but, um, do you have any last, um, interesting things you do want to share as well? Or last piece of, of advice to share with the audience?

 

Dr. Silverberg: ([41:07])

Yeah, I think this is a very exciting time for eczema. There’s been a ton of new research and development and this is an area where everything we thought we once knew is rapidly changing and it’s very exciting and we now have new treatments. We now have whole new understandings about how to potentially prevent the disease. And I think just keep, you know, following the news, keep following like this, learning more about what’s going on with the disease. And hopefully we’ll, we’re just, you know, a few steps closer to getting to a cure.

 

Abby: ([41:42])

Wonderful. Thank you so much. And if people want to, um, are people actually able to follow you or your research papers or even see you in person if they’re interested in finding out more or getting more information?

 

Dr. Silverberg: ([41:59])

So, I mean, if they want to come to Washington DC, that’s where I practice maybe a bit far to travel for everyone. But so I mean, you know, in terms of my publications, you know, I’ve published in a variety of different journals, so I guess I’m not sure how easy it is sort of keep track. I really should get better with social media and I’m going to make a concerted effort for everyone to try to at least post different articles that it’s just, it’s as you know, it becomes a full time endeavor.

 

Abby: ([42:27])

Yeah. And you’ve, you’ve posted over 200, how long does it take you to put together a research paper?

 

Dr. Silverberg: ([42:34])

Um, Oh, it’s, it gets faster and faster. The better, you know, the more proficient and the more experience you have. But it takes time. It depends on the study, but yeah, most, most studies would probably be in probably in the, you know, between one to four months, you know from in development phase. But some studies have some studies that are ongoing and it’s already six years in terms of enrollment. So some studies take a lot longer than others  to conduct.

 

Abby: ([43:07])

And they’re quite expensive too, right? I’m guessing

 

Dr. Silverberg: ([43:10])

they can be. They definitely can be.

 

Abby: ([43:14])

Well, thank you so much for sharing. I would love to have you on the show again, just to share more about, you know, some of the other papers that you’ve done. It’s a, it’s going to take you know, a lot to go through all the 200 papers that you’ve done, but it was just so much great information today and I really appreciate it.

 

Dr. Silverberg: ([43:32])

Sure. My pleasure.

 

Abby: ([43:33])

Yeah. And thank you. I think the audience will appreciate it as well.