The Healthy Skin Show 001: How to Protect & Strengthen Your Skin Barrier w/ Dr. Peter Lio

Programming Director: Divania Timmal-Jones

Many people don’t realize that our skin acts as a barrier to help protect us from the outside world. When that barrier fails, it can lead to a whole host of conditions from eczema to food allergies. I am so excited to have an expert on the skin barrier, Dr. Peter A. Lio, on this episode to talk about this important topic.


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Dr. Lio is a Harvard trained integrative dermatologist and clinical assistant professor of dermatology and pediatrics at Northwestern University Feinberg School of Medicine. He’s published over 100 papers in addition to a textbook on integrative dermatology. He specializes in using moisturizers to protect and support the skin and its function as your body’s outer barrier.

Today we discuss how skin is the first line of defense for your body. It keeps out the elements of the environment that would cause a lot of damage if they made their way in. When there is a breakdown in this barrier there can be a whole host of issues.

As Dr. Lio tells us, the proper use of moisturizers can play a big role in maintaining your skin barrier’s functions. (Don't forget… coconut oil is not a great option for rashed skin!)

Do you use moisturizer to treat chronic skin conditions? Tell me about it in the comments!


In this episode

  • What the skin barrier is and why it is important
  • Filaggrin and its connection to eczema
  • What you can do to protect your skin barrier if you have a deficiency in filaggrin
  • The connection between leaky skin and food allergies and what the research says about preventing the development of these allergies in the first place
  • What you should keep in mind when looking for a moisturizer
  • The role the skin barrier plays in conditions like psoriasis, rosacea, acne, and seborrheic dermatitis



“Our skin barrier is really critical to keeping our skin healthy and keeping the immune system and our other allergies in check. It’s our barrier to the outside world.” [2:38]

“If you have eczema, you know that you’re deficient [in filaggrin], either genetically or functionally.” [6:44]

“Wherever there is inflammation in the skin, the barrier is in trouble.”  [15:01]



Find Dr. Lio Online

Follow Dr. Lio on Twitter | Facebook

Handbook of Integrative Dermatology

The National Eczema Association’s recommended moisturizers

Why To NOT Use Coconut Oil As A Moisturizer


001: How to Protect & Strengthen Your Skin Barrier w/ Dr. Peter Lio FULL TRANSCRIPT

Jennifer:              Hi everyone and welcome back to the natural skin show. I am very honored today to have a guest with me whom I was advised to get in touch with by the great Dr. Aron, who you guys have also heard on this podcast. It was a wonderful interview. If you missed it, I'll put the link to it in the show notes, but that said, Dr. Aron asked me to get in touch with Dr. Lio and said Dr .Lio would be an amazing person to speak to and the more that I have looked up about Dr. Lio, the more I'm like, oh my gosh, I need to learn from this man because he's got a lot of cool stuff going on and that's why I'm so grateful that he's here with us today. If you don't know Dr.Lio, Dr Lio, Dr Lio is a clinical assistant professor of dermatology and pediatrics at Northwestern university Feinberg school of medicine.

Jennifer:              He received his medical degree from Harvard medical school. Pretty smart guy, it sounds like. Completed his internship in pediatrics at Boston's children college and his dermatology training back at Harvard where he served as chief resident in dermatology while at Harvard. He received formal training in acupuncture as well and he's written a textbook on integrative dermatology. He's published over 100 papers. Dr Lio, thank you for joining us.

Dr. Lio:                  Thank you for having me.

Jennifer:              I feel so honored. You're a super smart cookie especially on skin stuff.

Dr. Lio:                  Well you'll see. You will be the judge of that at the end of this, you let me know.

Jennifer:              So first of all we got this amazing recommendation from Dr Aron. He, clearly really respects your work and enjoys whatever sort of relationship that you guys have had going back and forth and sharing notes and whatnot. But , he recommended that I get in touch and one of the cool things when I was starting to Google you and sort of like internet stalk, you, I found this presentation and you were talking about skin barrier function. And so a lot of people don't fully understand what that means. They don't realize that their skin itself is a barrier to help protect us from the outside world. So could you give us a little bit of like a layman's term in layman's terms, so not doctor speak layman's terms of what is a skin barrier and why, why is it important and how important is good skin barrier function?

Dr. Lio:                  The, you know, the skin barrier is so critical. It's doing a lot of things. Not only is it keeping water in the skin to keep it hydrated and soft, but it's also keeping out all of the bad things in the environment. So it's keeping on allergens and irritants, chemicals that can cause reactions and also infectious agents like bacteria and viruses. And so our skin barrier is really, really critical to keeping our skin healthy and keeping the immune system and our other allergies in check. It's our barrier to the outside world. And I often remind people that if you trace your skin as you go around your lips, that becomes your gut lining. So the skin and the gut are very, very closely related in their role. They're both keeping us from the outside world. The gut doing it internally where we digest the skin doing it externally, but they really are part of the same epithelium.

Dr. Lio:                  And so when we think about what is going on with atopic dermatitis, there's been a huge revolution in this thinking just in the last decade or so. About 10 years ago there was a breakthrough paper and it was all focused on this protein called filaggrin. And filaggrin is really interesting. It's a structural protein in the skin and we know if you don't make enough of this protein or if you have a mutation that it does not make correctly, then what happens is, you have sort of what I like to call a leaky skin phenotype. Your, your skin is not holding water correctly and it's letting things in. Usually what this means is you just have very, very dry skin. And so specifically you have this condition called Ichthyosis vulgaris you look dry and Ichthyosis means fish, like cause you what almost looks like fish scales on the skin. But we know there's a huge correlation with that and atopic dermatitis or eczema.

Dr. Lio:                  So the breakthrough really came when people said, golly, this, this is a huge independent risk factor for atopic dermatitis. And at least in some percentage of people, you can say, by golly, the reason you have this disease is because you're missing this gene. So on one hand it's super exciting because finally we actually have the deepest possible root cause you can get, it's in your DNA, the fiber of your DNA is missing this piece. So that explains it. But on the other hand, it's a little bit frustrating because it says, golly, we can't fix this. Right? You're deficient in this genetically. So what do we do? So there's a couple of pieces. So that's part one. Part two where things got really interesting though, was that there are a series of papers that showed, even if you make normal filaggrin. So the gene that encodes for it is abbreviated, the F L G , you know, kind of abbreviated filaggrin FLG gene.

Dr. Lio:                  Even if that's normal in the presence of inflammation, you actually stop expressing filaggrin protein as much. So you become deficient. Yeah. Which is completely bizarre and totally interesting to me. So there's a lot of inflammatory cytokines, these inflammatory messengers that when they're active you become leaky skin. So this to me finished the whole story. It's like my gosh, wherever you start, if you start with genetically normal or if you start with abnormal, you end up with not making enough filaggrin and having this leaky skin. And so that's sort of the chicken and the egg concept for atopic dermatitis. Some people probably start fine but then have inflammation for other reasons that makes them deficient. Other people start deficient and they're already off to a bad start.

Jennifer:              So you could have, say you have an infection someplace, like a chronic longstanding infection. Could that inflammation that's caused as a result of like a longstanding ongoing inflammatory process, could that potentially also play a role in this?

Dr. Lio:                  It definitely could, because in those patients that are making normal filaggrin and have normal barrier to start, there probably is some trigger or triggers that then gets them into that inflammation cycle. So it could be an infection, it could be staff, it could be a viral infection, it could be just irritation. You know, one day you put on a cream that irritates you or as fragrance or clothing, for example, wool clothing, we know the wool fibers, natural fiber, a great fiber been used for of course millennia. But something about that fiber can in certain people irritate the nerve endings and drive them crazy. It feels itchy and uncomfortable. And so something like that could start the trigger. Then people scratch at the skin or rub at the skin and then they start this inflammation process, which then means they become deficient filaggrin. So now we have again, inflammation and barrier damage, the two key pieces to eczema.

Jennifer:              Wow. So, okay. So first of all, I guess the question is how, how do you know what the deal is with your body's ability to make this very critical protein?

Dr. Lio:                  It's a great question and it can be tested. Although it's still kind of experimental, it's expensive, there's not an easy way for anyone to get it done. But the more important point I think is that it doesn't matter because if you have eczema, you know that you're deficient either genetically or functionally. Right? So because of that, you know, either chicken and eggs theory, so it doesn't matter which way and if it's genetic, it's kind of reassuring, I guess you'd say. Well, I guess we know, but we're going to, we're going to treat it ultimately the same way because our goal with getting this under control is a couple of things. We can artificially protect the barrier and support the barrier using moisturizers. And that's what my area of interest and passion is, moisturizers, trying to support the skin, strengthen the skin and protect it. And we know that moisturizers, even if you do nothing else, no medicine at all, just bland moisturizers. That helps. That helps most people significantly with their eczema. Now as it gets more severe, that's not enough, but it's still an important part of the process to get that skin protected. But the most exciting piece is what came from a guy named Dr. Eric Simpson in Oregon just a couple of years ago. He published a paper and his hypothesis was, what if eczema is the first step in the entire, what they call the atopic March. All the other problems that go along with with atopic dermatitis. What if you just protect that skin from birth? And so they had a group of kids who were at high risk to develop atopic dermatitis. They put moisturizer on them from birth and they found that they were able to cut the development of eczema by 50% so that you can actually prevent developing atopic dermatitis just by strengthening that moisturizer barrier, that skin barrier with moisturizer. And the question that's still out there, but I think we're going to find that by doing that you also prevent all the other allergies, or at least some of the other allergies. You prevent food allergy because the newest thinking about food allergy, so for, for many, many years, 50 plus years, people would come into the office and say, okay, I have eczema, I have atopic dermatitis. What food is driving this? I gotta figure out what food this is because I know it's gotta be a food. Right? And we kind of said, well, yeah, maybe let's test it. And we do all this testing and people have on these exclusion diets. And certainly some people got better and those people really told the world about it. I was better, I cut strawberries or I cut gluten and dairy and they told everybody. But unfortunately the vast majority of my patients come in and they're really dejected. They're like, I tried, I spent, you know, four months and I really was good about my diet, but I'm still pretty miserable. Maybe I'm a little better. Maybe it wasn't as bad, but it's not clear. It's not the, it's clearly not the root cause for a lot of patients. So that was the party line, but it was confusing and never made much sense. But about three years ago now, a guy named Gideon Lack published a beautiful paper where they looked at kids who are at high risk for peanut allergy. And based on this, this observation that in Israel little kids often eat these peanuts snacks when they're teething and they found that they have like no peanut allergy there. And meanwhile, in America, we're going out of control of peanut allergy. So they fed these high risk babies, peanut snacks, and they found that they cut the risk of peanut allergy by a huge amount. And so this really is all starting to fit together, that if you have this leaky skin, so eczema, leaky skin, food, proteins get in through the skin and this process is called transcutaneous sensitization. So sensitizing through your skin and then you become allergic to the food. So in other words, it's not that the foods were driving eczema. I mean they can sometimes once you're allergic, then any allergy thing can kind of stimulate it. But it really seems like the first thing that happened was you had eczema, leaky skin, you then became sensitive to the foods. And it follows that if we protect the skin, keep the barrier under control and protect it and keep the eczema down, it follows that we should be able to prevent food allergy, which is really exciting. Could you imagine just preventing the whole thing? You don't have to treat it.

Jennifer:              That would be huge. And I want to echo what you're saying that a lot of my clients that come to me have tried. I can't even tell you how many very restrictive diets and I've seen no improvement. And one big problem for everybody who's listening is yes, sometimes you can go on certain types of restrictive diets and things improve, but then you can't get off of them. And so, you know, while tomatoes might be a trigger for one person, they aren't for everybody. So it's important to understand that there are underlying reasons why this is happening. And I oftentimes remind people that it's typically not the food that started it. It was something that caused the barrier to become leaky and allow the food or whatever it is to then stimulate the immune system in an unnatural way. So I just think that's an important, because we, I think in the wellness world we blame a lot on food and I think that's actually not super helpful, especially to people who have chronic skin issues. I just want to underscore that. I think that, and I appreciate you for sharing that. So someone's probably wondering, you've mentioned moisturizers a lot and I know that a lot of people that I've seen and I've talked to and I've done like the eczema and psoriasis awareness week, like their concern is like I bought all these lotions at the grocery store and that, you know, like they say like super dry skin. Like they, you know, they have all these fancy marketing titles that they're for eczema, they're for like extreme dry skin and nothing seems to work. So what do you find to be helpful when we're talking about moisturizing the skin from a medical perspective, what might be, what are some things we should think about?

Dr. Lio:                  I think the good news is there is there's been a huge amount of science and understanding of moisturizers and we are living in a really good time where it's hard to go wrong for the most part, especially if you pick one that's sort of designed for eczema, scanner sensitive skin. For example, national eczema association has a beautiful webpage that has the products that are sort of on their seal of approval that they've awarded the seal of approval. And the seal of approval is not perfect, but it really does try to weed out a lot of the, you know, the stuff that probably shouldn't be used for patients with eczema. And it has many, many dozens of products now that are safe. So, so long as you pick, you know, sort of a good one at baseline, I really encourage people to experiment and explore a little bit. There is a very, very personal piece to the finding the right moisturizer and sometimes a family will come in and they'll say, we've tried a whole bunch, we don't like any of them. Or particularly kids who say everything burns and stings. That's really, that's unpleasant. So I'll actually take a little time and I'll go to my sample closet and I'll make a little palette of a whole bunch of different ones in my favorites and I'll put it on right there and we'll just do it together. I'll say, how does this one feel? Do you like that? And when you know, the patient sort of says, Oh, I love that one, that's great. I'm like, that's your, that's your moisturizer. That's going to suit you because you like it. It feels good. I want it to feel good. So we try to find that right balance. But the truth is you could go a lot of ways in general. I think we like heavier, more ointment based ones because they tend not to have preservatives. They're a little bit, you know, more occlusive. They never sting or burn that they're a little easier. But some people really don't like the feeling of that on their skin. Sometimes that even feels hot. Other patients really want to avoid petroleum. I'm not personally against petroleum products, not for the skin. I think they're really nice cause they're so inert. They just sit on top and really cause you know a great barrier without being absorbed. But some patients really just would prefer to avoid them and I respect that. So there's a lot of non petroleum products. I of course love natural products too. We have to be a little bit careful because a lot of times some of the plant products will have tons of plants. You know, they're trying to get all the best and so sometimes you can have an allergen tucked in there. But I really, I love coconut oil. I love sunflower seed oil. I do like you know, a lot of the products that use that as part of their blends. And so there's, there's so many great options and I think, you know, check out that NEA National Eczema Association page, you can get a ton of options, including some of the natural ones, you know, I think they're awesome.

Jennifer:              And I'm going to put a link to that page. I'll find that for you guys who are listening and I'm gonna put a link to that in the show notes so that way you can just easily click through. I'll do the work for you guys and you're welcome. And I'm trying to think like, so for anybody, okay. So if you have eczema and you're listening to this and you're like, all right, so I got that something has gone awry, whether I am not producing filaggrin or I'm just making some sort of like, not fully well formed filaggrin whatever's going on, my skin's leaky. Is it at all possible to, for somebody maybe who's listening, who has like psoriasis or anything else, like is it possible that that could show up in other or dermatitis like seborrhea dermatitis? Like is there any research for those people that are listening that might be like, Oh, maybe this does apply to me or should they just go, well I guess I don't have this issue?

Dr. Lio:                  No, I think you're right on there is pretty good evidence that the skin barrier is deficient in of course eczema as we're talking about, but also psoriasis, rosacea, acne, seborrheic dermatitis, and probably other things that I'm not thinking of off the top of my head. But we know wherever there is inflammation in the skin, the barrier is in trouble a lot of times. And so we want to help with that barrier. So almost all of my regiments for whatever kind of inflammatory disease that I'm treating will have some kind of a moisturizer that helps. And I really like that. And I think that is important because if it is leaky, not only do we lose the water, but we also then have the risk of junk getting in that we don't want. So maybe your primary problem is psoriasis, but as you have this leaky skin, maybe your secondary problem then can become the beginning allergic to things or you're getting irritated by other things. So we really want to be on top of that no matter what. Whenever there's inflammation.

Jennifer:              Okay. And, and I think the last point we'll make, and then I think what we should do, if you're game for this, I think you should come back. I mean, I feel like there's more information in your brain that you could share with us that we would love to hear. Because there's just, this is a really great conversation and I don't want to overload people who are listening, but I, I sense that you have a lot of experience here and I love the fact that you also straddle the more natural approach to things. Like you've done something really interesting that I, I wish more dermatologists would do and be open to other options aside from just steroid cream, antibiotic cream, maybe antifungals.

Dr. Lio:                  It's a bit of an uphill battle.

Jennifer:              It is. It is. And I hope that maybe you'll join us with that, but is this why when people say, I put steroid cream on my skin and it seems like things get better.

Jennifer:              It's for my perspective and my experience cause I had dyshidrotic eczema on my hands. It's almost like, it's like putting the cap on inflammation that's happening. So could one argue that we don't have to go deep into it right now, but when you're using these topical steroid creams as you're saying, like this inflammatory process is causing a problem that could then create this leaky skin barrier. It's like we're using the steroid. I do think that people should kind of use a steroid while they're going through whatever process they're going through, if that's been prescribed by their doctor. I did. I'm not topical steroid creams, just being very mindful and cautious about how much you use. But I think that people don't fully understand that the steroid cream does connect with the inflammatory piece. Is it?

Dr. Lio:                  I think you're right on. And you know, I think with the steroids, I also, I will use them when we need them. I feel like they,re a tool, but I'm really cautious about how long we're using them, how, how, how frequently people are using them. And most importantly, what is the pattern, you know? So what worries me is people who say, I used it. I got better. Almost everybody gets a little bit better. But then as soon as I stopped I flared up and I was worse than before, and sometimes then the natural thing is just go stronger and stronger and stronger. So I hit the brakes really quick. I'll say, you know what? This is, we're going the wrong direction. You know? The way it should be is if we're doing the right thing, then you should say, Hey, I used it for a bit, I got better, I took a break, I was great for awhile.

Dr. Lio:                  That's what I'm listening for us. But I don't hear that. Then we say, okay, it's sort of akin to the house is on fire and we keep putting out these little fires. But it's like, you know, at some point we need to think, okay, there's a reason, you know, maybe the, the, the drapes are hanging over the stove. We have to make some kind of a structural change. We can't just keep putting out this fire. On the other hand, I sometimes have patients who don't want to use steroids at all and I respect that of course. But it is tough too because it's like, well the house is on fire and I also want to find out why. But right now we got to put out the fire because if we wait and try to do a root cause analysis, you're going to burn your whole house down. So let's put out the fire and work together to solve it. But you know something, you've got to kind of straddle that line.

Jennifer:              Right. And I think that's the balance. Like I have clients that are like, I'm just going to throw it away. And I'm like, no, don't do that. Don't do that. I still have mine, I've been a year free of hand eczema. I'm so happy. But it's still upstairs in the medicine cabinet. So

Dr. Lio:                  I mean that's great. It's there at the ready. It's you know, in case of emergency. Lastly to use it briefly, if you felt like you were overusing it then we hit the brakes and say “Hey this is not how it's meant to be used.” But in those small doses I think it can really help and you know it can change your life.

Jennifer:              Exactly. So I think this, this is sort of like veering in a much bigger conversation and there's so much more to talk about. So I hope that you will come back.

Dr. Lio:                  I'd love too.

Jennifer:              Great. Well I just want to make sure everybody can find you. So you can be found online over at Chicago, eczema.com you've also got a Facebook page and a Twitter account. So I will link to all of this. I will also link, if you're a practitioner listening and you want to check out the book that I found online cause I was Googling around and found Dr Lio's book. It's called “The handbook of integrative dermatology and evidence based approach.” How cool is that? It also has very good Amazon reviews, by the way. I will link to that. It is in my shopping cart and I have every intention of purchasing it and I feel really honored that I'm talking to one of the authors. This is so cool.

Dr. Lio:                  It's my pleasure. Thank you so much for having me and I definitely will come back.

Jennifer:              Awesome. Well, thank you so much.

Jennifer Fugo, MS, CNS

Jennifer Fugo, MS, CNS is an integrative Clinical Nutritionist and the founder of Skinterrupt. She works with women who are fed up with chronic gut and skin rash issues discover the root causes and create a plan to get them back to a fuller, richer life.

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