299: What Is Eczema Herpeticum? w/ Dr. Peter Lio

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Today we're going to talk about Eczema Herpeticum — which we've never done a deep dive on with a dermatologist before. Today's guest is not only a favorite guest of the show, but he's seen it all in his practice and will delve into why we need to be very careful trying to fight off viral infections on our own with a compromised skin barrier.

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.

Have you or a loved one ever suffered from eczema herpeticum? Please tell me what worked and what didn't in the comments!

Or, listen on your favorite app: iTunes (Apple Podcasts) | Spotify | Stitcher | TuneIn | Subscribe on Android

In this episode:

  • What is eczema herpeticum + what causes it?
  • Eczema herpeticum vs Staph infection – what's the difference?
  • Possible complications with eczema herpeticum outbreak
  • DIY treatment vs seeing a doctor – what's the best route?
  • Eczema herpeticum treatments (medication vs supplements)
  • Is eczema herpeticum contagious?
  • Can a herpetic outbreak occur in other skin conditions?


“If it gets near your eye, it can actually start to involve the eye, which is dangerous. That can be really an eye emergency. You can permanently damage your cornea and have trouble. ” [03:33]

Any kind of a barrier damage could lead to the herpes virus doing this. So it could be from poison ivy, it could be in some of the genetic conditions like derriere disease, it could be from people with blistering disorders, it could even be from just irritation.” [14:18]


Find Dr. Lio Online | Twitter | Facebook

Healthy Skin Show ep. 106: What The Heck Is Eczema Herpeticum? w/ Abby Lai

Healthy Skin Show ep. 176: Dealing With Recurrent Skin Infections w/ Dr. Peter Lio

Healthy Skin Show ep. 107: Symptoms Of A Staph Infection On Your Skin

Healthy Skin Show 246: Everything You Need To Know About Skin Tests (Done By Your Dermatologist) w/ Dr. Peter Lio

299: What Is Eczema Herpeticum? w/ Dr. Peter Lio FULL TRANSCRIPT

Jennifer Fugo (00:04.174)
Dr. Lio, I am so excited to have you back on the show! Thanks for being here!

Peter Lio (00:15.035)
Thanks for having me back, it's a pleasure.

Jennifer Fugo (00:17.174)
So we're gonna talk about something we've actually never touched on before in terms of what you've talked about here and that is eczema herpeticum. And I feel like some people know what this is and other people don't. And I personally believe, especially because this year actually made a point to do an episode on shingles, I feel like there's some viral things that can pop up with the skin that we should as patients be more aware of. Can you talk about what is eczema herpeticum?

Peter Lio (00:53.543)
Sure, so you know the the herpes virus there are a few different flavors of it as we know but the two really common types are HSV1, the herpes simplex virus type one and HSV2 herpes simplex virus type two. And those are the ones that can cause most commonly a cold sore. Tons of people get cold sores, it's probably more than like 80, maybe even some populations, 90% of people have been exposed to that. So many people can get a cold sore, many people though don't get cold sores, but if you check their blood, you'll actually see they have antibodies against HSV virus. They've been exposed to this virus, which is remarkable, which is why sometimes a patient will come and say, I think I had a cold sore and I wasn't sure, so my primary doctor drew the HSV test and it was positive so I'm sure it was a cold sore and I'm like I'm not sure because many people who even if they never report a cold sore have that positive exposure to it they have their body has made antibodies to it so so many of us have been exposed. Now, in a normal host, a normal person without any skin diseases, they might get a cold sore. They might get, you can get, you can get basically a herpes infection in other places. If you get it on your fingertip, it's called a herpetic Whitlow. It's really painful, really uncomfortable. It can be kind of scary. You get these blisters there. But you can also have, of course, genital herpes, which is, you know, historically kind of they separated. HSV1 was more on the lips and face. HSV2 was in the genitals. But those rules are kind of broken. We actually see both can be anywhere, and that can be uncomfortable for people. It can be something that is not necessarily chronic, but it's relapsing. You get a breakout, you're kind of miserable, then it goes away. It can be very painful. When people have a cold sore outbreak or a genital herpes outbreak, they often feel pretty crummy. You can actually even have a fever. You can feel run down. I mean, your immune system is fighting this viral infection. Okay, so that's kind of normal, sort of is not normal, but that's what most people might experience. If you have impaired skin barrier, so our eczema patients are one of the most important groups for this, what can happen is, instead of just coming out in one area, it can now spread all over the place because the barrier is down. And that is what we call eczema herpeticum, where you get basically the herpes virus all over the place.

And typically you'll see it as lots of little very similar looking, the term we use is monomorphic, kind of one shape. They look punched out little either ulcerations or little like superficial erosions or more commonly by the time we see it they're scabs. So you have all these little tiny scabs and they're widespread. When that happens, it's kind of dangerous because now you have you basically have been a petri dish for this virus. The herpes virus is now going crazy and loving all this open skin, these broken sort of imagine if it's in a neighborhood where all the windows and doors of houses are removed, it's like, oh, we can just walk in any, you can do anything you want. There's no security. So it goes crazy. And those patients can not only feel really crummy, feel sick, feel bad, but if it gets near your eye, it can actually start to involve the eye, which is dangerous. You know, that can be really an eye emergency. You can permanently damage your cornea and have trouble. So that's sort of the most common pattern we see. Sometimes it's more localized. We'll have patients with just a small patch of eczema herpeticum, other patients that can be very generalized. And typically if it's more widespread than just a tiny patch, we're gonna have them hospitalized for a day or so to get IV antiviral treatment. Yeah, it's a big deal.

Peter Lio (04:07.191)
I mean, now, do most cases cause serious trouble? No, I'm sure most cases out there probably come and go, but some cases can really hurt people. I mean, there even is a mortality rate. You can die from this, honest to goodness. So it can damage your eye, you can die from it, it can make you very, very sick. So we have to really keep an eye on this and take care of it. We also know that many times, particularly when it's widespread, staph aureus bacteria, takes advantage of that. And we get a true super infection, an infection over an infection, right? So we have the viral infection wreaking havoc, and then we have staph saying, oh look, open doors and windows, here we go, and it takes advantage. So you have a lot of patients who have both bacterial and viral infection at the same time, and as you can imagine, they're pretty sick at that point.

Peter Lio (04:49.815)
Absolutely extremely uncomfortable, open sores everywhere.

Peter Lio (05:00.259)
It really can be anywhere. A lot of the cases I see are face and neck, but I've had patients where truly their whole body's involved. I've also had patients with more limited areas. I have a photo in my collection from many years ago of a foot lesion. It was sort of just a little area on the foot of a child that the parents called me and said, the eczema's doing pretty well overall, but the spot on the foot, I said, bring him in. I'm worried that it's infected. I was thinking staph bacterial, but sure enough, punched out monomorphic erosions. Now we can do two things, well, more than two. We can at least do two things to diagnose it.

So of course we're going to look at it. So clinically we can usually make the diagnosis, but if we're not sure, we can take a little tiny scraping of it. It doesn't really hurt, very gentle, just scrape some of the cells. And we do a stain called the Tzanck preparation. A Tzanck preparation lets us look right under the microscope, right there. And I can see pretty, pretty well if it is herpes or not, because we're looking for these things called multinucleated giant cells. So that's great. You can also do a rapid test where they use a fluorescent antibody. And that's a very good test too. That antibody test usually can be back if you're in the hospital, sometimes just a couple of hours. They'll call you. I'll have the patient wait, you know, within an hour or two they're like, oh, yep, it is positive. A lot of times we'll start treating even if we're not sure though because it turns out that herpes virus, although can be kind of nasty, it is fairly easy for us to treat in a safe way. And of course we have the medicine acyclovir and its close cousin valacyclovir. Those guys have been around for a long time. They're really cheap. They do a great job in general. They're very, very safe. You know, most patients don't have major issues with them. So a lot of times if we're concerned this is an issue, then we're going to say, let's just treat you first. I don't even want to wait for the results. Of course, the third thing you can do is you can do a culture. If you don't have the ability to do the Tzanck Prep or a rapid antibody-type fluorescent stain, then you can culture it, but the culture can take a long time. For a viral culture, it could take days or weeks even. And sometimes patients will say, can you speed up the culture? And it's like, no, you literally just swab it and you just keep checking. You're waiting to see if it's going to grow. So if you have a lot of virus, maybe it'll grow pretty rapidly. But if you don't have much virus, it could take weeks before you see it.

Jennifer Fugo (06:58.074)
Oh my. So you mentioned a child. Is there an age bracket that this impacts or it's an equal opportunity offender in terms of eczema herpeticum?

Peter Lio (07:09.127)
That's a good question. There may be, I don't know offhand if the literature has found certain age groups, but in my own practice, my own experience, it's been the whole gamut. I feel like it may be a little bit more commonly in kids. Most of the patients I've seen are younger, but I have seen it in all age groups.

Jennifer Fugo (07:25.158)
And this would look different than a staph infection. Like is there a way, like for a parent, if they're listening to this, because I think sometimes they go, oh, well my child's rash is flared, or a client will tell me my skin is flared, and I'm like, tell me the symptoms. Like please be very detailed, what are the symptoms? And then I'm like, I think you need to see your dermatologist, because I'm always like, is there a possible infection, and I wanna make sure that they see a doctor as soon as possible. So is there a way to just, as a lay person or a patient? Is there, cause I know you're saying it's a punched out lesion and I'm not sure, in all honesty, somebody might not know what that actually looks like. So is there something like a hallmark or a telltale sign that they could look for to be like, I think this could actually be eczema herpeticum?

Peter Lio (08:12.963)
Yes, I think in general, the most important things that I'm looking for are if somebody says they have pain in their skin, generally speaking, pain is bad. We do not want pain in the skin. So especially new pain. Some of my severe atopic dermatitis patients, they do have pain a lot. That's their norm. But when somebody has new painful area, that's kind of a warning sign right away because that often is a sign of bacterial or viral infection. So pain is a red flag. We should trust that pain. We should get checked out.

Open sores is another one. If there are open sores, oozing, kind of weeping, anything like that, that probably warrants being looked at pretty quickly. I mean, again, how do we know? Sometimes we don't, and honest to goodness, sometimes a patient comes in and I'm like, this kind of looks like it could be eczema herpeticum, but I'm not sure, so I'm gonna do one of those tests. So even, you know, even if you have a lot of experience, it can be difficult to say, but I'd much rather have them come in. And sometimes even to an urgent care, if there's no dermatology office or pediatrician office open, they could pop into an urgent care and say, I'm worried about this, and at the very least, they could potentially culture it, they could evaluate it. Sometimes like I say, they'll just go ahead and treat it empirically and I'd much rather have them do that.

When I talk to my colleagues in primary care or emergency medicine, I'll say, if you're not sure, just treat because this is the kind of situation, if we miss it, we can really be in trouble. This patient's going to get very, very sick and if we accidentally give somebody a Acyclovir who didn't need it, low risk and reasonable. For my own body, if I weren't sure, I'd say, please give me the Acyclovir. It's very, very safe. We can always stop it. If the culture comes back negative and they're doing much better, you could say, okay, you only needed it for a day, but we weren't sure.

Jennifer Fugo (09:44.79)
That's good to know. And I think the other thing as you were talking is I would imagine if you start developing a fever, you feel lethargic, like you start feeling like you're sick and having these combination of symptoms that could also be good feedback for your dermatologist or the primary care, whomever that you see to know that, that happened around the same time. So another question that I'm thinking is you're saying the skin barrier is compromised, this virus is essentially going wild having a party at this poor individual's expense. Are they contagious? Is this like something where we need to be careful? You know, I just know with like I remember in my father's office, and now he was an ophthalmologist, we would get a lot of cases of shingles on the face and he'd be like, we have to be careful, especially if they're oozing and whatnot. So is this the same instance where we need to be cautious of sharing, you know, like, do we have to wash our hands? Like what's appropriate and does this matter or does it not?

Peter Lio (10:49.143)
Yes, I do think it is fairly contagious. You know, it's probably as bad or worse than somebody with active cold sores. So if you met somebody at a party and they had a whole bunch of fever blisters and cold sores on their lip, you would be careful. It doesn't mean you can't shake their hand, but you certainly wouldn't want to give them a kiss. You certainly wouldn't want to touch those areas. And this is even, you know, I would say taken to the next level when you have them all over and they're all open because they're probably the most infectious when they're open like that. And there's the serous fluid which contains the virus. So for those patients, yeah, for the parents, we'd want them to be washing their hands very carefully.

Again, for a normal person with normal skin barrier, they can probably fight off the cold sore virus, especially from hands and feet, but being careful because the lips are pretty sensitive or if there are little micro cuts. And that's another reason why we want to put them on treatment. It turns out once you've had about a day's worth of treatment with the acyclovir type medicine, generally speaking, it can't infect anybody. So you kind of knock it out very, very quickly, even though the patient might not feel that much better yet. We know that they're not nearly as infective. It goes down close to zero.

Jennifer Fugo (11:45.93)
Wow, that, okay, that's really good to know, especially if it's a child and you've got other siblings running around the house and whatnot, you don't wanna pass it to anybody else. And I guess too, in terms of timeline, so if you're able to identify an outbreak,

Peter Lio (12:19.831)
Yes, I think for some people, especially if we haven't treated it, because the other thing we didn't mention are there are people that get it recurrent. They'll have it multiple times. I have a few patients. In fact, at Boston Children's Hospital, they did a study a number of years ago to try to understand why do some people keep getting eczema herpeticum. And they found that there are some specific immunodeficiencies. Their immune system is a little weak on certain areas. It's kind of fascinating. So some people may be more susceptible to this in the first place, and some people are susceptible to it over and over and over, which is really tough.

So for those patients, we kind of have seen that they've had it over and over and maybe haven't had treatment. And you're right, it seems like maybe on the order of a few days to up to a week or two, and the body usually can fight it off. But I've also had patients where they have come in with an ulcer or an area that's been affected for months and I'll culture it and say, oh my goodness, this has been going on for months and this is eczema herpeticum. Your body has been able to contain it and they haven't been dangerously ill, but they can't clear it. So I think the whole gamut is possible, and that's why again, once we start treating it, most people are better within just a couple of days. It can be quite dramatic and that's why it's such a satisfying thing to treat. When you identify it, say aha, you get them on the medicine and they call you the next day say oh my goodness I feel so much better. Everything's already healing and generally it heals without a trace. It does not leave scarring. So you have all these sores but they're very superficial and they heal up beautifully.

Jennifer Fugo (13:39.15)
Okay, that is really good to know. I didn't, so this is a condition I never, I fortunately never developed when I had eczema. So it's, I don't have personal experience. I've heard stories. Abby Lai was on the show. You guys remember a while ago talking about her experience with this and she has had it recurrently. It's just so interesting. And I think this is not just a big deal for those with eczema, correct? Is it possible for other skin conditions to develop some sort of herpeticum outbreak?

Peter Lio (14:12.939)
Yeah, exactly right. So it turns out the general category is called Kaposi's varicella form eruption. And this was decided that people realized they put it together that boy, any kind of a barrier damage could lead to the herpes virus doing this. So it could be from poison ivy, it could be in some of the genetic conditions like derriere disease, it could be from people with blistering disorders, it could even be from just irritation. If you have an irritant dermatitis on your hands from something, you could potentially get this. So it really can happen. And then flipping it the other way… Can other viruses do this? Yes, yes they can. And again, they can do it in any of these conditions, but particularly atopic dermatitis. And one of the most concerning ones that we see is called eczema vaccinatum. So eczema vaccinatum actually is when people get the smallpox vaccine. It's not actually smallpox, right? It's this vaccinia vaccine. It's a cousin of smallpox that makes you basically resistant to it. But we don't really do it in the US anymore, right? But you'll see people who are either older or people from another country, they'll have that scar. That was the smallpox vaccine. That's vaccinia. So, but some military people still get it if they're gonna be in areas where there's still potential for smallpox. Pretty terrible disease. And it turns out that if kids or adults, anybody who has atopic dermatitis, but the classical story is a kid has a parent who's in the military. The parent gets the smallpox vaccine. They come home and see the kid. Well that's a live vaccine. That's a live attenuated vaccine. So they expose the kid to it unknowingly, you know, innocently. And then the kid gets eczema vaccinatum.

It's super scary. It's super rare, but it can be fatal. And there was an amazing case a number of years ago. Actually, it happened here in Chicago. And the long story short was that exact setup happened. The child had, with bad atopic dermatitis, had a parent who was in the military. The parent got that vaccine and came home and then went back. You know, they, I think they were in for just like a weekend or something and the kid got very, very sick. The kid was admitted to the hospital. Everyone thought this must be eczema herpetocum, right? This is what it looks like. It had those ulcers. Everything looked pretty good. But they were so sick and they had them on acyclavir and all this.

It wasn't responding. And finally, a really sharp pediatric dermatologist came back. I guess she had been away from the office or from the hospital for a bit. And she said, no, no, no, this is vaccinatum. And when they put it together, they said, oh my goodness, the parent had the shot, this and that. So they used an experimental drug that worked against smallpox and its cousin, vaccinia, and they saved the kid's life. I was like crying during the story. When I heard this case presented, I was saying, oh my goodness, because the kid really was in trouble. Apparently it was experimental drug. The CEO of the company had to fly in with the briefcase handcuffed. The whole thing, it was like out of a Hollywood movie and they saved the kid.

Jennifer Fugo 
Wow. So, other conditions… do you ever see psoriasis where they can develop herpeticum or is it more…?

Peter Lio (16:56.507)
Isn't it weird? Yeah, psoriasis, even though it's kind of similar to eczema, those patients tend to be tougher against infection. We think maybe in part because they have more of the certain kind of immune cells like neutrophils in the skin, so they don't get as many viral or bacterial infections. So usually not, but other conditions, these dermatitis of any kind of origin. Oh, the other thing I was gonna say, so eczema vaccinatum is that one we talked about, but there's also one called eczema coxsacchium. So we know that hand, foot, and mouth disease, right? Lots of little kids get that. It's really uncomfortable. You get these little blisters on your hands and feet, sometimes on the buttock area as well and in the mouth. And when you have bad barrier for your skin and it's an eczema, you can get a very severe version of it. Same concept. So eczema coxsacchium, also kind of fascinating. So it really can, this pattern really does apply to other things.

Jennifer Fugo
OK, so now as you're talking, I've found something else that may be helpful to folks. We have no biologic drugs… Is it possible… does that make you more or less susceptible to herpeticum?

Peter Lio (18:12.919)
Yeah, so we know that with like the conventional immunosuppressants, things like prednisone and cyclosporine and methotrexate and mycophenylates, those guys probably do increase the risk. I mean, we know they increase the risk of infections throughout. They probably increase the risk of things like eczema herpeticum and shingles. You know, they often are looking for a shingle sign and so that that also can be elevated.

With the biologic agents like to dupillumab and its cousin and the one coming, there's a whole bunch of those those guys at least in atopic dermatitis world because remember the psoriasis ones are a little bit different so I'm really talking about the ones we have so far for atopic during biologics is a bigger class so there it's possible some could cause other issues but I want to be clear but these really do not seem to increase skin infections and interestingly they seem to actually decrease the number of skin infections overall and that's pretty cool so we think that they really are kind of running that very, very delicate needle to suppress just the part of the immune system that's going crazy but not really damage the other parts. And because it's so targeted to this TH2 system, the more allergy-based system, it really seems to leave the rest of the immune system okay, which is why we like it so much in part. You don't have to worry about tuberculosis, which you do for some of the other agents. You really are concerned. You're going to give somebody, if they have TB exposure, their body's fighting it off and now you're going to turn that off. And now the TB is like, thank you. Now I can escape my prison. But the biologics that we have so far really don't have those risks, which is part of why we love them and which is also part of why they've been able to be approved down to such a young age, down to six months of age.

Jennifer Fugo (19:42.054)
And I think one last question that would be helpful is, I think from an alternative standpoint, lysine, the amino acid lysine is used a lot to help with cold sores, folks who get cold sores. And I've heard, you know, Dr. Mamina Turegano had talked on the show about maybe it might be helpful to help with shingles suppression for those who keep getting shingles, but like there's, you know, not the greatest of data on that. Do you feel like…

Peter Lio (20:31.723)
I definitely think it's worth a try. You know, one nice thing about something like lysine is just an amino acid. It's really safe, it's really gentle, it's not super expensive. That's exactly the kind of thing I'd be happy with somebody trying and experimenting and giving me some feedback. Other people have tried things like zinc supplementation because that kind of helps with antiviral effects overall. So people could play around. Yeah, I agree with Dr. Turegano. I don't think there's really compelling evidence yet, but it would be cool for someone to study it more because we do need help for these patients who, especially those who are really susceptible to getting it over and over again. They're kind of desperate sometimes. What we usually end up doing, so it's like, well, what do you do? Why don't you have them do that? Well, because what we usually do if they're really getting it multiple times is we'll put them on a dose of acyclovir or its cousin valacyclovir daily. There's a suppressive dose. And again, because fortunately it's a pretty safe medicine, we can get away with doing that. And I usually do it for maybe six months or a year and typically they stay free. They don't have any issues. And then we kind of say, okay, let's stop it and see if maybe your body's in a better place. Maybe the virus has sort of settled down. We've chased it away enough. It's probably still IN our body- It lives in our nerves, right? But we'll hopefully have cooled it down and many patients then can go for a long, long time without it and some of the patients later say, I'm getting another one, can we go back on? And you can. So that's usually what we do, but yes, I would love for a more natural approach to this and hopefully someone will take up the mantle.

Jennifer Fugo (21:47.494)
I hope so. Well, this has been fascinating. And I'm so glad that we had this conversation. And I think one of the benefits to having a conversation like this is it helps patients identify issues, know they need to seek treatment or get help or at least get looked at, right? Because that's sometimes that's the hard part is like, maybe it's just a flare up, maybe I can tend to it at home. And this is one instance where you and I've talked about skin infections and different things. But this sounds like this is one instance where it is really important to get treatment and to see a doctor who can identify this quickly so that it doesn't get out of control.

Peter Lio (22:28.963)
100%. I feel like I tried to tell my patients there's no stupid reason to call, right? Especially in dermatology, we see people who come in for skin screening, right? They literally just are like, Doc, check me over, make sure I'm okay. There is no dumb question. So if you have a new spot or a painful area or something that's not healing or you don't feel well, and you think, could this be related to my skin? We want people to come in. Now, I also know that it's easier said than done. Our schedules tend to be a little crazy, but please know it's never a dumb reason to call and check in.

Jennifer Fugo (22:56.898)
Well, thank you so much for joining us again. Of course, I will put all of your links and everything in the show notes. And I feel like because you are one of the healthy skin show favorites, everybody knows you, they love you. They love these episodes that we do together that really help give guidance on what to ask for so that people can better advocate for themselves. And ultimately, I always believe the goal is to get the treatment that you need sooner rather than later.

Peter Lio (23:29.783)
Well, thank you. Thank you for having me. Thank you for all the good that you do. You put such great information out there, and I really appreciate it. And I can't wait to see you at Eczema Expo in just a couple months here.

"If it gets near your eye, it can actually start to involve the eye, which is dangerous. That can be really an eye emergency. You can permanently damage your cornea and have trouble. "