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Have you ever heard to just put honey or aloe on your rash? I URGE you to think twice on treating an angry rash at home before knowing what it is. Sometimes, it can be life threatening as you will hear from my guest today who had a patient have sepsis!
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Not to mention, it could be tiny microscopic bugs, which gives the shivers just thinking about it.
My guest today is Dr. Peter Lio, a Clinical Assistant Professor of Dermatology & Pediatrics at Northwestern University Feinberg School of Medicine.
He received his medical degree from Harvard Medical School, completed his internship in Pediatrics at Boston Children’s Hospital, and his Dermatology training at Harvard where he served as Chief Resident in Dermatology. While at Harvard, he received formal training in acupuncture.
Dr. Lio has written a textbook on Integrative Dermatology and has published over 100 papers.
Join us as we discuss all the different types of skin testing for various conditions, which your doctor could run.
Have you ever had any of skin testing done and it helped tremendously? Tell me about it in the comments!
In this episode:
- Why you need a dermatologist on your team to help rule out infections + more serious issues (even if you want to do things more naturally)
- Different testing types and when you do each one (AND for which condition)
- What are scabies and Demodex mites, and why could Ivermectin help?
- How does patch testing work?
- Thoughts on supplementing with B12 if you have a cobalt allergy
- Hidden sneaky source of benzoyl peroxide (if you have this allergy)
Quotes
“Scabies are these little, teeny-tiny mites, they're invisible to the naked eye, but not to the microscope. So what we do is we'll scrape the little parts of the skin or even better is we can scrape under your nails because if you're itchy, you're collecting little scabies mites under your fingernails.” [08:51]
“The biggest thing I think for bacterial infection is skin pain or tenderness. If it's just itchy, I'm not as worried, but if a patient calls me and says, it hurts, it's sore. Then I'm like, whoa, that's a super four-alarm fire.” [11:04]
Links
Healthy Skin Show ep. 001: How to Protect & Strengthen Your Skin Barrier w/ Dr. Peter Lio
Healthy Skin Show ep. 037: Nickel Allergy And Eczema w/ Dr. Peter Lio
Healthy Skin Show ep. 104: Topical B12 For Skin Rashes w/ Dr. Peter Lio
Healthy Skin Show ep. 136: Alternative Solutions For Rosacea w/ Dr. Peter Lio
Healthy Skin Show ep. 176: Dealing With Recurrent Skin Infections w/ Dr. Peter Lio
Healthy Skin Show ep. 216: Could Your Rash Be A Sign Of Lymphoma? w/ Dr. Peter Lio
Healthy Skin Show ep.107: Symptoms Of A Staph Infection On Your Skin
Follow Dr. Lio on Twitter | Facebook
246: Everything You Need To Know About Skin Tests (Done By Your Dermotologist) w/ Dr. Peter Lio FULL TRANSCRIPT
Jennifer Fugo: Thank you so much, Dr. Lio for coming back to the show as always, you're one of my favorite guests and I really appreciate you being here.
Dr. Peter Lio: Well, thank you for having me. It's always a pleasure.
Jennifer: Well, so today I appreciate you being interested in answering my questions about this. Number one, today we're going to dive into this situation that I find a lot of clients and readers and listeners in, where, for example, I'm not a medical practitioner, but there are times when a client will express to me that they're in a flare and they don't really want to go back and ask for help, because they're afraid that the doctor's just going to give them steroids. But in the same regard, I'm hearing symptoms that sound like an actual infection. And I get concerned because as you and I both know, because we've worked on some cases together, an infection can sometimes get really bad. So it's important to have somebody who has that medical background look at what's going on. And so there's confusion a lot of times about the type of testing that they've had done in the past versus what could be helpful now to help them identify what's actually causing the flare.
Jennifer: And so I'm so glad that you wanted to talk about this. So we're going to be talking all about that today, different types of tests that you as a dermatologist can do. And what's the difference between them, when can they be useful. Especially sometimes you could get a particular type of test multiple times throughout the course of your journey because it might show different things, especially when it comes to a skin infection. So anyway, what are your thoughts on that? Because I think a lot of times they think dermatologists don't do testing, but you do.
Dr. Lio: We definitely do. And I would say there are some things that we're really good at and some things that we're not so good at. One of, I think, the biggest unmet needs in our specialty overall is we need better, safer, long term management for chronic conditions, right? That's why I send so many people to you, we need other ways to approach these things because sometimes we're like a one-hit wonder, we keep giving the same thing over and over. That being said, where we're really good is more acute things, right? Acute infections and complications like that. That's sometimes when you often want to go to a more general dermatologist who can really help us get to the bottom of that. And it's true, there's a number of different types of infections that affects skin conditions and can be secondary to them.
Dr. Lio: And I love the way you put it. They can come up over and over again. So let's start with one near and dear to my heart. Atopic dermatitis, right? Now, atopic dermatitis by itself is not an infection. We know that the microbiome is playing a huge role, both in the gut and on the skin, but we wouldn't call it an infection by itself. That being said, because that skin barrier is so weak, many patients have recurrent staph aureus infection of their skin and probably have dysbiosis imbalance all over their body. But when it gets bad enough, if you don't treat it, you can get really sick. Actually, I always tell the story, I had a patient who was in the office waiting for me and I was running a bit behind, as we are wont to do.
Dr. Lio: And I finally came in the room and the patient was on the bed listless. And I was talking to his mom, we're chatting for a while and I looked at my watch, I'm like, it's the middle of the afternoon. I'm like, is he always like this? And the mom said, no, he is been really like this just for the last couple days. So I walked over to him and I realized that he was quite sick. He was feverish. He was erythrodermic, red all over and I picked him up and we actually walked him right to the ER, he had a blood infection. So he got infection through his skin, in his blood, sepsis, he was very sick. He needed several days of IV antibiotics in the hospital and then was okay and was able to complete it by oral, but really scary. So a bacterial infection through the skin can be potentially even life-threatening, even though it's quite rare. And of course, more localized infections like impetigo or a smaller cellulitis, they really should be evaluated and treated.
Jennifer: Yeah. And so in this particular instance, let's just say, for example, you didn't think that the situation was that severe where you were like, ER time and they're in the office and they're complaining of burning, hot, red, super itchy skin patches. I think a lot of times the confusion that at least I initially hear was, well, I had a biopsy two years ago and it didn't really tell me anything. So I don't see the point to going back now for this. And I'm like, well, no, what you want to try to get is a culture where they're going to look to see what's there. So can you talk a little bit about the difference of, what exactly is a culture and then what is a biopsy?
Dr. Lio: Perfect. That's a perfect opening. So, right. So what are some of the different techniques we can do? So a skin biopsy is something that's great. A skin biopsy is where we numb up the skin and we either do what's called a shave type, we scoop a little bit off with no stitch or a punch type, where we actually use a little instrument, it looks like a tiny cookie cutter when you take a little plug of skin. And then we usually put a stitch on to close that up. Now both of those are really important tests because sometimes patients or families will think, oh, is it going to go to some lab? And they do some computerized analysis? No, no, no. It literally goes to a pathologist, right? Another doctor who is trained to look at skin samples, in this case, ideally a dermatopathologist, but there's other types of pathologists, general pathologists who can look at anything, GI pathologists who look at stuff from the gut, neuropathologists who look at brain tissue.
Dr. Lio: I mean there's really specialized and they do specialized staining it under the microscope, they're going to give an impression, a description of what they see. So a skin biopsy is not really a test, right? It's a diagnostic procedure. And sometimes we'll even have a discussion about it. The pathologist will call me and say, this is really interesting, I saw this kind of cell type under there, the blood vessels look really strange or what's going on? There's a lot of activity on the surface of the skin and then we'll have a back and forth. So it's really important. And it helps us not only rule out some bad things, for example, certain types of cancers that can affect the skin like cutaneous T-cell lymphoma, but it also can help us rule in things, they can say, there is a ton of little blisters, are you sure this isn't a contact dermatitis?
Dr. Lio: And sometimes I'll say, maybe we should test again and do that. So that's a biopsy. Now a biopsy can show signs of an infection too, but it's not very good at that, honestly, because in signs of an infection from a biopsy standpoint, really tend to just be a lot of inflammation. We're just seeing the bodys response to it. Better for a bacterial infection is a swab culture. So we literally just take a sterile Q-tip essentially, just a cotton swab and it's part of a little kit and we literally just rub it on the area and pop it in a special kind of medium. And then that grows. So sometimes it's funny too, a patient will call me the next day and say, well, can you tell them to rush that culture? And I say, well, I could tell them, but we can't rush the bacteria, right?
Dr. Lio: They literally put it on a plate and they let it wait and we watch and every day they look and see if something's growing. I mean, it sounds crude, but it's a very functional test. It's old fashioned, maybe in the future, we'll have some tri-quarter or some way to do genetic analysis immediately, but right now we literally grow it out. And when it grows, then they can run tests on the back bacteria. So that's the best way to know, not only what is the bacteria on your skin that's causing trouble, but also then they can do what's called sensitivities. They can tell me, hey, you know what? This bacteria's really nasty and it will not respond. We actually did a test and it doesn't respond at all to X, Y, and Z antibiotic.
Dr. Lio: And that's really, when people say MRSA, methicillin-resistance staph aureus, that's literally what it means when they put methicillin or it's cousins oxacillin on it, it didn't respond to it. So they say, this is a nasty bug, it didn't respond to a conventional antibiotic that should work. So don't use what you were going to use. Pick one of the other ones that will definitely respond. They can even tell us, they can show us the sensitivities and say it doesn't like this antibiotic, this kills it so use that one. And that's so important. Now there are some other tests we can do too very quickly. We can do fungal analysis. So sometimes a complicating issue is fungal infection. There can be yeast type overgrowth on the skin. Like if we think about tinea versicolor, right? The malassezia zal splotchy that can be a complicator of eczema or its own condition.
Dr. Lio: We can do a thing called a KOH or potassium hydroxide preparation, I scrape very lightly. For kids, I say, I'm just going to brush the skin. It doesn't hurt. We brush, take some of the flakes. I go right to the microscope right around the corner. And I do a special stain on there. We use potassium hydroxide, hence its name. And then I wait for a minute and look under the microscope. So right there, I can tell you in one minute, whether or not it's fungal infection. And that also works for ringworm of the body, or of the scalp anywhere like that. We also can do a scabies prep, right? Sometimes peoples have scabies. Scabies are these little, teeny-tiny mites, they're invisible to the naked eye, but not to the microscope. So what we do is we'll scrape the little parts of the skin or even better is we can scrape under your nails because if you're itchy, you're collecting little scabies mites under your fingernails.
Dr. Lio: And then I just scrape underneath and I look under the microscope and I will often bring it in. I'll bring my camera in and I'll say, have a look, look at what we have. And they'll see the bugs, they're little tiny bugs and they're on your skin. And that's all those things we just said, bacterial infection, fungal infection, scabies are all super treatable. And we can usually treat them definitively. It's one of the few times we're excited when that happens. We're like, we can help, this we can do, I can't cure your eczema sadly, but I can cure this darn fungal infection or I can get rid of scabies.
Jennifer: And we talked before a little bit about staph infections. And I will link it up, that episode in the show notes, but I wanted to remind people listening that it's not just staph, right? You could have a strep infection on the skin. You could have a pseudomonas infection. I remember you specifically mentioned those two bacterial issues as well.
Dr. Lio: Absolutely. So staph is a big one that we deal with all the time, but there are dozens of different bacteria that can affect the skin. Pseudomonas is an important one because that's the one that causes hot tub folliculitis, where people will hang out in a hot tub over the weekend, maybe at the gym or at a hotel. And then they get all these little pustules. And that's pseudomonas, usually that one can cause that. Pseudomonas can also cause an infection underneath the nail, we call green nail syndrome. So there's a number of different bacteria that can do it. Strep, we think of strep throat, but you can also get strep around the anal area. And as a skin infection, it can happen anywhere on your skin. And there are many other, sometimes it's more exotic, but no doubt that staph is the big one and that we deal with on a day to day basis.
Jennifer: That's good to know. And I hope that everyone knows too. And I just want to emphasize this. If you say went a year ago and had one of these culture swabs done, but today you're having an issue. You can't refer back to that other culture. Like it's a snapshot in time, correct?
Dr. Lio: Exactly. And you may have an infection once and then we'll get you better and then six months later, have it again. So the biggest thing I think for bacterial infection is skin pain or tenderness. If it's just itchy, I'm not as worried, but if a patient calls me and says, it hurts, it's sore. Then I'm like, whoa, that's a super four-alarm fire. We have to make sure because that skin pain while it can happen, just from some conditions, eczema is known to have some pain, it is a pretty good indicator that there could at least be a chance of infection going on.
Jennifer: And can I ask you, just one moment, you mentioned cellulitis before. Could you just talk to people about what that is? Because I think they may have heard the term in the past, maybe like an older relative had cellulitis but I don't think many people actually understand what that is specifically.
Dr. Lio: Yeah. So cellulitis refers to a superficial skin infection. So the most superficial of all is impetigo, right? That's where you could just a scaly, scabby stuff on top it, we often call it the honey colored crusting and that is so superficial. It really hasn't gone deep into the skin yet. But as you get a little bit further down, then we have what's called cellulitis and that's usually it's sore. It's a red area of skin that's involved. It's tender to the touch. Of course, beyond that. It can actually get even deeper into the skin. We can have things like fasciitis, where it goes way down and so on and so forth. And of course, even cellulitis though can get into the blood. And that's a problem if it's in the blood.
Jennifer: So if you have any of these symptoms, this is where you really want to see your doctor. That's really important. That's not something that you're going to be like, oh, I'm just going to apply some manuka honey or put some Alo. I know that there are remedies out there for things, but I have worked with some clients who, I would say, just really didn't want to go get help and waited a bit too long and ended up in really dire straits, like full body infections, which Dr. Lio and I have had conversations about because he also then ended up seeing them. And it was a pretty serious situation for a lot of individuals. And so we just want to impress upon you that it is important to get medical attention. Not everybody ends up in the ER, but you don't want to end up in that boat. You definitely don't want to end up in that boat.
Dr. Lio: Exactly. That's the biggest thing, because the infection can cause so much trouble and it can even be life-threatening, we really want to make sure we take care of that aspect. And that is something that can really be a true emergency if you have an infection of the skin.
Jennifer: Now with Demodex mites, would that also be like a scraping as well?
Dr. Lio: Yeah. So that's great. So that's a little bit less commonly done, but absolutely. So those little guys, there's two variants of the Demodex. They're called folliculitis and brevis. The folliculitis are a little longer, the brevis are a little shorties. They're also microscopic, you can't see them with your naked eye, but we can actually scrape very gently. And then I smear them on a slide. Now for those, I don't use any stain. I just look right into the microscope and it's so cool. They're still alive. So I actually have some videos. I'll show you one day, you see them crawling around and they're just eating all the little sebum. They eat the sebum. So they of in our little pores and then now there are normal commensals so they're on everybody's skin, but in certain conditions like rosacea, they seem to go crazy.
Dr. Lio: And so there's even a condition called demodicosis where you can just get an overgrowth of them, but we scrape and all of a sudden you see like five or ten of them around a follicle. You're like, Ooh, there's too many. And that is one of the things we can again, treat pretty easily. We actually can use, well, one of the medicines is now infamous because it's been discussed in terms of COVID right. Ivermectin. So people take ivermectin, they've been talking about that as potentially a COVID treatment. I don't know really whether or not it helps, I guess there's some evidence says maybe it helps a little bit, which is interesting. But as a topical agent, it turns out that its main use is an anti parasitic. So it kills Demodex really great, which is neat. So we use it both in rosacea and in demodicosis, which is neat.
Jennifer: Wow. Okay. So let's talk a little bit about more allergy-type testing. So there's patch testing versus the prick testing. Do you do that? Do you send someone to an allergist? Because I do get questions about this like, who would actually do that type of testing?
Dr. Lio: Yeah. And there's a lot of confusion around testing, but you're right. So there's at least two major types of testing. There is the testing that looks for IGE. So that would be the kind of allergies that make hives or hay fever or conjunctivitis that is normally done in an allergist office. And there's two ways to do it. There's prick testing, where they just poke at your arm or poke at your back and then wait about 20 minutes or 30 minutes and see if you hives or there's the blood testing for it. Okay. They actually are looking at the IGE levels in the blood, they're they both have their pluses and minus, many allergists will do both and correlate them. But generally speaking, those are looking at IGE type allergies, urticaria hives, hay fever. There's a conflation and confusion because people say, well, how do you what I'm allergic to for my eczema? Didn't that tell you?
Dr. Lio: And it's like, well, not really. That would just tell you what you're getting hives to. Now, hives can be a trigger for eczema, but there's a whole different kind of testing that's usually not done by allergist. Some do it, but typically done by dermatologists is the type I do. And that's called patch testing. Now patch testing is where you come in. It's much more involved. And instead of a 30 minute little thing, we actually put stickers on your back and these things called finn chambers, they're tiny little metal discs. And they put a little chemical underneath and we put tape on your back. We usually do 80, and it's called the North American standard. So there's 80 different little circles on your back. You have to leave it on for two days.
Jennifer: Two days?
Dr. Lio: Yeah, because this is a T-cell mediated response, so we're not asking what makes you hive? Because that's an interesting question, but really not so much related to eczema. We're now saying what gives you eczema? It's the ultimate functional test because then when we peel this off on Wednesday, we put it on a Monday, we take it off on Wednesday. I literally am looking for eczema change. So I'm looking for that redness, the swelling, scaling. Sometimes it's so severe, they get a big old blister where it was. And so this is your skin telling me very directly, hey, this one drives me crazy. This chemical, this cocamidopropyl betaine in shampoo and soaps, this preservative is driving me nuts, this natural coloring or whatever it may be, or fragrance, we can find it. And then I can tell the patient, your skin really hated this. And again, it's awesome because I can show a picture of their back and they say, oh my goodness, what was that one? Okay. That one was methylparabens. So we got to avoid it because your skin hates this and even a tiny amount of exposure can drive this reaction.
Jennifer: Can I ask you, so with the patch testing, you said there's 80 little discs. So does it include like food products or if the patient seems to react to a particular shampoo or something like that, how do you determine what the 80 items are?
Dr. Lio: Great. First of all, there are thousands of allergens to choose from. So you can pick thousands and thousands of them like anything under the sun, including foods and people do it. That gets a special name. It's called atopy patch testing, APT. And that's really interesting because it's not as understood or approved or done as commonly, but some people are experimenting with it to actually put food products on the skin and see. It just seems to be a little bit less reliable because part of the issue with food is that it can be irritating in and of itself. So, if you put some tomato sauce on your arm, you might be reacting to tomato, but it's also acidic. Your skin's not designed for that. So this is the confusion and truth is this is a confusion about a lot of different things we test for.
Dr. Lio: But over the years people have refined it. So they find the perfect percentage or they find an ideal vehicle for it. Many of them are held up in Vaseline. Some of them need water though. They can't be in a greasy thing. So there's all these little tricks and stuff that they've learned over the years. So these are a little bit more codified. That being said, there are some food products and for example, Balsam of Peru, it's a plant product and it's present in a lot of foods. So if people are allergic to it, sometimes we say, we need to go on a Balsam of Peru-free diet. Nickel is another thing. Nickel is very common and for really severe nickel allergy, if we can't get it under control, unfortunately you have to go on a low nickel diet.
Dr. Lio: It's almost impossible to go nickel free because there's nickel in everything. I mean, it's a lot of fruits and vegetables, right? But we can go on a low-nickel diet and I hate doing it because it's brutal. It's like no canned foods. So you can't eat spinach or chocolate, all this stuff. But usually we don't have to, I will tell you one last story because I think this is neat. We had a patient who showed a really strong allergy to benzoyl peroxide and was like, hmm, because she didn't have acne, she wasn't using any benzoyl peroxide products. And I just didn't think much of it. You can react to things you're not really seeing, maybe it was from years ago or something, I didn't think too much of it, but she had terrible lip dermatitis and we couldn't get it under control.
Dr. Lio: Finally, a friend of mine told me, they bleach flour with benzoyl peroxide sometimes. And I was like, hmm, that's interesting, I didn't know that. And I asked the patient about flour and she said, oh my God, you're not going to believe this, every morning, I go to my favorite bakery and I get some kind of a pastry and they have flour on top. So she switched the pastry. She was still eating flour, baked flour, but it was the raw flour on top where they sprinkled it. She switched her pastries, lips cleared. So we knew it, it took me months because I didn't make the connection between benzoyl peroxide bleaching the flour. I mean the whole thing is crazy and I've only seen that one time. But now I remember that because that was a time where we… Right? I mean, isn't that a wild story?
Jennifer: Well, your friend told you this and you've now shared it. So now everyone will know that benzoyl peroxide is used to help bleach flour. I did not know that, that is wild. Wow. My goodness. Can I just ask real quick cobalamin, that's also one of the, I guess, metals that you test or the substances-
Dr. Lio: So cobalamin is vitamin B12, but cobalt is the other [inaudible 00:21:14]
Jennifer: Cobalt. I'm sorry. I'm sorry. Cobalt. I meant cobalt.
Dr. Lio: Cobalt and nickel often run together. Absolutely true. And cobalt is used in some different industrial processes too. So yeah. We'll often see that overlap for sure.
Jennifer: For somebody who has a cobalt allergy, it's always been confusing for them and actually for me as well. Do you recommend they avoid B12 supplements as a result of that?
Dr. Lio: Typically I don't. Yeah. I think they're distant enough that I'm not too worried that there's a connection. Honest to goodness. So yeah. I've not seen that come up for a patient that's clinically relevant.
Jennifer: Okay. That's helpful. That's helpful for people to know, to maybe feel okay, they're just testing it out and seeing how they do because it is confusing. There's so many things that can cause issues. And it's good to know that there are other tests that you can ask for, or that you could have a conversation with your dermatologist or like you said, an allergist about to see what's going on to figure out like, is it a potential exposure that could be one of the factors? I recently had a client, she loved this natural deodorant and she was allergic to something in the deodorant. It was a very ubiquitous, natural product that's used in a lot of things and she's like, I can't use this. I actually am allergic to it. And since she's reduced that exposure, she hasn't had as severe of rashes in obviously the armpit area so that's a good thing.
Dr. Lio: Absolutely.
Jennifer: But thank you so much for clarifying all of this. I know everybody listening as always, you've got I think the top listened to podcast episodes on the healthy skin show. And we'll add this to the pile because I know that you're just so generous with your time and your wisdom and helping to educate the patients so they can ask better questions and have more educated conversations with their doctors. And I think that is so important, especially when you spent years suffering from something to be able to ask the right questions or ask about tests and whatnot. It's a part of the journey. It's a part of advocating for yourself.
Dr. Lio: I couldn't agree more. Well, it's always so fun to be here and I really do hope it helps some people even just giving some hope or some new ideas and helps that discussion because it is complicated. And every little bit of knowledge I think can bring us closer to finding some relief.
Jennifer: Absolutely. And so for anybody who is looking for a dermatologist, you can check out Dr. Lio, he is in the Chicago area. I'm going to put all of his links and everything in to-do, the show notes for this episode. And thank you so much, Dr. Lio. I really appreciate your time.
Dr. Lio: Thank you for having me. I'll see you soon.
Jennifer Fugo, MS, CNS
Jennifer Fugo, MS, CNS is an integrative Clinical Nutritionist and the founder of Skinterrupt. She works with adults who are ready to stop chronic gut and skin rash issues by discovering their unique root cause combo and take custom actions with Jennifer's support to get clear skin (and their life) back.
Anyone like Dr. Lio, or close to him, as far as extensive dermatology investigation & diagnosis in the West Palm Beach area of south Florida?
You could try Dr. Fabrizio Galimberti or Dr. Hadar Lev-Tov. I believe both are through the University of Miami. They may be helpful options near you!