Are You Really Allergic to Penicillin? (Update)

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27:20You could imagine that artificial intelligence will soon be helpful in sorting out things like who's allergic to what. But we're not there yet. For now, allergy is often a guessing game, a bit of grasping in the dark. It's estimated that roughly 40 % of humans have some kind of allergy that's expected to rise to 50 % by the next decade. Why? We've already heard from a couple of allergists, but to answer this question, we need someone with a broader view. We need a medical anthropologist. Medical anthropology is looking at all the social and cultural factors involved in healthcare systems. We think about how all those beliefs and politics and economics, how all of that factors into the choices people make about their health and how they view their health.

28:13This is Teresa McPhail. I'm associate professor of science and technology studies at Stevens Institute of Technology. McPhail recently published a book called Allergic, Our Irritated Bodies in a Changing World. She writes that roughly half a billion people suffer from food allergies alone. That's been a puzzle as to why an immune cell will take a look at something that is otherwise harmless and decide that it's not and do it after sometimes years of tolerating it just fine. And suddenly now it's a problem. Just tell me why and how you became interested in the notion, the big notion of allergy.

28:54My father died of a bee sting. He died from an anaphylactic reaction to bee venom. He had had a reaction in the past, but it was fairly mild, just swelling at the site. That's mostly what happens to anyone who gets stung by a venomous insect. And he died on the second sting. We really don't know how many times he was stung because he was a Vietnam vet. So there's a chance that he was stung prior to that. And I got curious about my own susceptibility to such things. Years later, I was diagnosed with allergies, but I am one of the rare people that do not react to skin or blood tests. I have low levels of IgE, the antibody that is driving the allergic response.

29:42So there's no way to tell what I'm allergic to, except that clinically you can see the signs and symptoms that I am allergic to something. So what are you allergic to? I think, based on my years of detective work, that I'm allergic to grass and probably ragweed and maybe dust mites. Can you just say what an allergy is and what an allergy is not? Oh boy, how much time do we have? This is part of the problem. There's a lot of confusion about what an allergy is and isn't. The easiest answer I can give you is that an allergy is when your body responds to something that is otherwise harmless and triggers an immune response.

30:28If your immune cells are not involved in the response, then it is not an allergy. The classic example is milk allergy versus milk intolerance. On the surface, if you have a mild milk allergy, it's going to look the same, perhaps an upset stomach, feeling kind of gross, some gassiness. But the difference is with the intolerance, there's something else going on. In this case, you're not able to digest lactose because you lack an enzyme. But it's producing symptoms that would seem familiar to someone whose immune cells, whose T cells and B cells are producing antibodies and attacking that milk protein.

31:15Except that the allergy can, you know, escalate. You can get a skin rash. You can get wheezing. And you can end up in the ER with a full-on anaphylactic event. That's not going to happen with intolerance. But if you have mild forms of this, you're going to be confused and you might just assume that you have an allergy. And the only way to know for certain is to see an allergist. The problem there is we don't really have enough of them. They're specialists and you need a referral to see one. And so a lot of people are out there self-diagnosing. Are allergic rates rising or is there just more awareness and or diagnosis and or treatment?

31:53We think as far as we can tell that they are rising. but it's complicated. We know that rates of asthma and hay fever started to rise post-World War II, like 1950s, 1960s, and continued right up until the 1990s. And now they seem to have been flattened. But what has been rising in the wake of that are rates of food allergies. We know this because of several reasons. One is you can look at ER visits. You can see when someone is showing up with asthma or with a rash, like a very bad eczema eruption, or they are having anaphylaxis. The other thing that we can track is EpiPen or adrenaline prescriptions.

32:39Those raised three to four times from the 1990s to around 2018, 2019.

32:50As with penicillin, the discovery and isolation of adrenaline is another great story for medical history. I won't go into the details here, but it's worth reading about if you're so inclined. A dose of adrenaline or epinephrine administered in an EpiPen, for instance, is the first line treatment for anaphylaxis. When Teresa McPhail cites the huge spike in EpiPen prescriptions as evidence of a huge spike in allergies, well, she also points out that much of the demand was driven by the supplier. Mylan Pharmaceuticals marketed the EpiPen aggressively across many channels. Over one 10-year period, McPhail writes, they hired more lobbyists than any other U.S.

33:35company. This led to a relabeling of the drug by the FDA, which made more people eligible to take it. Mylan also lobbied state legislators as a means to get more EpiPens into schools. They also partnered with Disney to produce children's books about allergy sufferers. So how big is the allergy market? The global market for epinephrine is about$2 billion a year, with 60 % of that sold in the U.S. If you look at hay fever, one recent study put the cost of treating Americans at over$4 billion a year, more than a billion of which goes to medication. If you look at the entire category of allergy remediation, the global sales of tests and treatments is around$40 billion a year.

34:24So how much of the allergy boom has been driven by more allergies versus well-run pharmaceutical campaigns? It's hard to say. There are a variety of factors that may be driving allergy increase. Some research shows that environmental and chemical disruption may play a big role. I asked Teresa McPhail about some other potential drivers. Many, many, many people have by now heard or read about the notion of allergy rising because we, especially we of the children variety, are not exposed to enough things, pathogens or allergens or whatnot, that we don't roll around in the dirt and so on. Right. So in the 1980s, this is after the massive rise of asthma, we're starting to see food allergies.

35:17An epidemiologist was curious about this and started collecting data on families and realized that older siblings seem to have more allergic disease than younger siblings. The theory was that older siblings bring home colds and track in bugs to expose their younger siblings. And there was something about that earlier exposure that had somehow protected these younger siblings. It was called the hygiene hypothesis that has morphed over the years to what is now called the old friends hypothesis, which is nice, isn't it? That's a nicer way to put it, that there's something about getting the right exposures to the right bacteria or the right viruses and fungi that will help train our immune system.

36:14You're born with a novice and naive immune system that hasn't seen anything. And you're born with an innate immune system, which means there are things online from the very beginning that just act as a brute force response to anything that threatens the individual. And then you have an adaptive immune system, which involve your T cells and your B cells and your antibodies that remember the things that you've been exposed to. And so the theory is those have to be trained and they have to be trained in the right order and they have to be exposed to the same types of bugs, microbes that they would have been evolving with for millennia.

36:57The theory is that we've changed so much that some of those are missing. It has confused our immune system to the extent that you're seeing more allergic disease because you're not getting the training. It feels as though every time I go to a restaurant these days, the server will ask, is anyone allergic to anything? Do you know anything about that? It's basically advocacy. And at the forefront of that is a group called FAIR, which is Food, Allergy, Research, and education. They're privately funded and run by a group of parents. When I started researching the book, one of the first people I sat down with was Helen Jaffe.

37:40Her and her husband, David, are some of the founding members of FAIR, and they also have helped to fund the Jaffe Center at Mount Sinai for food allergy research. When they started the foundation, it was because two of their children had quite severe food allergies, but it was at a time where no one was doing this. They live here in New York City, and they had to take the train down to Johns Hopkins to see Dr. Hugh Sampson. He's a renowned food allergist and researcher, and he has been doing this for over 40 years. But at the time, there were maybe half a dozen people focused on food allergy. And so initially, Helen told me that their focus was really on education and research funding to try to figure out what was going on, why the rates seem to be rising, figure out more about the biological mechanisms that drove this response.

38:41I spoke with Dr. Hugh Sampson now, we're talking about years later, and he said he used to fight with people to get them to recognize that their issue was food allergy, and now he fights with people to get them to recognize that their issue is not food allergy. Can you explain? I do see on the FAIR website that 50 to 60 percent of all blood tests and skin prick tests for food allergy testing will yield a false positive result. Correct. So that sounds absurdly bad. Is it not as bad as it sounds or is it that bad? No, it's bad. It's bad. I mean, diagnostics are one of the sticking points. It's one of the reasons I can't tell you how many people actually have an allergy.

39:29Because we're stuck with primarily the skin tests, which were invented in the late 1800s by a UK physician, Dr. Charles Blackley. Wait, the late 1800s? Yes. And if I exhumed him and revived him, he would have no problem giving a skin test today. What about false negative? That's what we should be really concerned about. That is the better situation. It's around 95 percent certain if you do not respond that you are not going to respond in real life. So that's good news, at least. Yes, that's good news. That's why we still use them, because it's almost like a differential diagnosis. us, we can rule some things out.

40:12So you mentioned in the book that your aunt and your grandmother were allergic to penicillin. Yes. Given everything we've discussed about testing or the lack of great testing and the murkiness surrounding this area, do you think that they actually were allergic to penicillin or maybe? In my grandmother's case, we know because she was in the hospital and had an actual skin eruption and reaction to penicillin. I honestly don't know about my aunt. Sorry if she's listening to this, because to my knowledge, she's never been tested. So I don't know. She does avoid them, though. At the end of the day, I suppose it doesn't matter.

40:56I suppose it doesn't matter, Teresa McPhail says. That's what I used to think, that a penicillin allergy is no big deal since there are other newer antibiotics that do the same thing. But the allergists we heard from earlier, Elena Resnick and Kimberly Blumenthal, they told me that that is simply not accurate. Resnick told me about a pregnant patient of hers who showed up with a penicillin allergy on her chart. Penicillins are an amazing drug also because we know them to be safe and effective in pregnancy. When a pregnant woman goes in to deliver, if she is colonized with group B strep, which is a very common vaginal infection, she must be given antibiotics before delivery to ensure that the baby is not exposed to the group B strep.

41:43So the antibiotic of choice for group B strep is in the penicillin family. Mom comes in, she's ready to deliver, she gets a dose of penicillin, she gets her second dose four hours later, she delivers the baby, everything is fine. If she is thought to be penicillin allergic, Instead, she's given vancomycin. Vancomycin dosing interval is every 12 hours. So if she's not dosed appropriately, the baby can be considered inadequately treated. And that leads to all sorts of other potential decisions. Maybe getting put on antibiotics, maybe going to the NICU. Again, the complications just from this penicillin label are intense.

42:21So in this particular scenario, this mom went in to deliver. She was thought to be penicillin allergic. They gave her vancomycin. She developed Redman syndrome from the vancomycin, which is just what it sounds like, where the body becomes completely red and flushed and other medications have to be given. And then she had a wound infection from her C-section because she was still thought to be penicillin allergic. They gave her clindamycin to treat the wound infection. And she developed C. diff from the clindamycin. And how did that play out? So when you develop C. diff, then you have to be put on oral vancomycin and then treated usually for two weeks.

43:03It's just a nightmare. It's one thing after another. And then she came to see me and we were able to clear her of that penicillin allergy. Why did she come to you in the first place? So her OBGYN, we also rely on the OBGYNs to find people who in their charts have this penicillin allergy. The problem with that is we're not going to test a pregnant woman just on the off chance that she does end up being one of these rare people who's truly allergic. Obviously, we don't want to put a pregnant woman into anaphylaxis. So we're sort of stuck with that label, which is hard for the OB because then their patient gets a simple infection.

43:34They can't use a penicillin. So a lot of the OBs will say to their patients, before you get pregnant again, better go get cleared of your penicillin allergy.

43:47The fact is that a mislabeled penicillin allergy, and as we've established, the vast majority of penicillin allergies are mislabeled. This is a serious thing. The risk of post-surgical infection is much higher. So are your chances of dying. Kimberly Blumenthal from the Mayo Clinic published a study comparing the long-term outcomes of 60 ,000 patients with a penicillin allergy in their medical record versus more than 200 ,000 patients without. We did an all-cause mortality study in a very nicely controlled observational study. 14 % increased all-cause mortality. Wait a minute. If being labeled penicillin allergic is producing that many more deaths, what exactly are the adverse outcomes that you're avoiding if you're able to take penicillin?

44:36There's avoiding antibiotic resistance, C. diff colitis, avoiding too long of hospital stays, avoiding surgical infections if you had needed an operation. And then there's avoiding other adverse events that result from a choice of antibiotic that is just more toxic and by its nature caused more renal failure or caused more diarrhea or whatnot. This may be impossible to say, but let's say there are two observationally equivalent patients. Let's say me and let's say I have a twin. Okay. And one of us has been labeled penicillin allergic. The other hasn't. We have the same medical problem come up.

45:19I'll let you pick the problem. One of us receives a penicillin drug. The other is not eligible to do so. Even if his allergy isn't real, we think it's real. how would you think about comparing the medical and economic outcomes of person A and person B? It's such a no-brainer. I mean, when you give me this description, what comes to mind is two people who have strep throat. Strep throat and a penicillin allergy label. One person gets penicillin. That's indicated for penicillin. Strep throat goes away. No long-term sequelae. They're fine. It was cheap. And then the other person gets a Z-Pak, a zithromycin.

45:56and it doesn't fully go away. Then they call back and they get another antibiotic. Maybe this time they get a bigger antibiotic and that causes some problem. They might get a tonsillar abscess. They get a quinolone, ciprofloxacin unnecessarily, or some other medication. I mean, I don't know what any of those are, but all those syllables sound bad to me. Yeah. There's no rule like the more syllables the antibiotic has, it's worse. I wish it were that simple.

46:28OK, that's not simple. But this is. Misdiagnosed penicillin allergies are costing all of us a lot of suffering and dollars. So why isn't more being done to solve this problem? Because the public doesn't decide which grants get funded. That's coming up after the break. This is Freakonomics Radio, and I'm Stephen Dubner.

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48:43Once you know about the benefits of penicillin and how millions of people wrongly believe they are allergic, you can't help but think about the costs of this misdiagnosis. Not just the bad health outcomes and the complications, but the financial costs too. That's why some specialists are pushing for more testing and delabeling of people who think they are allergic. That might cost a lot up front. But when one in 10 people think they have a medical handicap and they don't, this actually presents an opportunity to save money. It might even be worth testing every single person whose medical history says they are allergic.

49:23Here again is Kimberly Blumenthal from the Mayo Clinic. We can evaluate for penicillin allergy with simple tests. And these simple tests need to be delivered to that 10 % of America and reimbursed appropriately and taught to a non-specialist workforce. Could be a welcome to college visit, a welcome to Medicare visit. How much money could you save by doing this? Just my health care system would be millions. If we evaluated penicillin allergy, delabeled the appropriate ones, we would save millions of dollars, just my healthcare system. So it must be in the billions. You'd save at how? You save on antibiotic expenditure.

50:09Just because penicillins are cheaper than the other antibiotics? Yes. You'd save on adverse effect avoidance. Meaning penicillins don't cause as many adverse effects as other antibiotics? Yes, and some of these adverse effects lead you to the emergency room and another hospitalization. You would save on surgical infections, a tremendously costly thing. Blumenthal tried to make these cost savings a reality when she worked in the Mass General Hospital system. In our hospitals, without an allergist involved, there is sort of algorithmic care that can clear allergy in low-risk situations with just a protocol.

50:49Just a little bit more observation. You're already in the hospital. You're being observed. Your vital signs are already on record there. Yeah. And is the idea as simple as you feed the key vital signs into the allergy algorithm and see if indeed there's a likelihood that that person is not allergic and then maybe do some challenge testing? Is that the way it works? We do it when patients have infections. So we don't do it electively, like if you're there for something not related. But if you have an infection that an allergy is getting in the way of best care, we have a two-step drug challenge process.

51:25And as long as the patient's healthy enough to do that, we do it. So we give a small amount, watch the patient, give a full amount, watch the patient. And then if that's the drug that they need to be treated with, they just continue that drug right then and there. Since there is a treatment for the allergic response, but the default is to not give penicillin if there's a suspicion of allergy, what would happen if you just flipped the default and said, no, no, no, we're just going to give penicillin. And if they happen to be in the small group of people who are allergic, then we'll watch and we'll treat it.

51:57Is that such a terrible idea or would you kill a bunch of people by accident that way? You would kill some people by accident. And in America, it's just a nonstarter. Because we don't want to kill anybody, you're saying? Well, there's also this doctor, first do no harm. Like the oath we take, and it feels wrong to just disregard allergy labels entirely. The hospitals where Blumenthal worked have achieved a 9 % delabeling rate over a decade. The national delabeling rate is less than 1%. There's something interesting to notice about Blumenthal's approach. Many specialists in many industries are always trying to grow their leverage to become ever more powerful gatekeepers.

52:44Blumenthal is moving in the opposite direction. She wants to shift leverage away from the allergists in order to help more patients. This would happen through better technology, better training and better regulation. In some states, pharmacists are now allowed to perform the skin tests for penicillin allergy. Last year, a Republican congressman with Democratic support reintroduced the PAVE Act. That stands for Penicillin Allergy Verification and Evaluation. It would fold allergy awareness into annual wellness visits and the preventive welcome to Medicare visits that Blumenthal mentioned earlier.

53:21So that all sounds good, but let's not get too excited. Overall, the false positive problem in penicillin is under-examined and underfunded. I can tell you with confidence that I was the first penicillin allergy grant that the NIH funded in 30 years. Whose area is it? Is it infectious disease? Is it allergy? It's multidisciplinary. Is it surgery? Is it obstetrics? Because penicillins are used by everybody. Dentists. It was very hard to know who takes ownership of something that crosses every single discipline. When disciplines cross, disciplines compete. Given the cost of medical research, these can be multi-billion dollar competitions.

54:03There's a pecking order in medicine. This is Thomas Plattsmills. I'm a professor of medicine at the University of Virginia, and I've been studying allergic disease for a long time. And where does allergic disease fall in the pecking order of medical research? It's actually much worse than anything you imagine. Neurosurgeons are at the top. Cardiac surgeons. And all these people fight with each other, but they know that at the bottom, there are dermatologists and psychiatrists and allergists. I got very little from the university, a little bit in the first few years. But then basically in the last years, nothing.

54:42We've always had to get our own money. And I was getting NIH money, and the NIH has been very generous. This last time, I actually got a one on a grant. It actually means you're in the top 1%. And then I got a merit award, and the merit award is absolutely wonderful because from 18 to 28, I'm funded by the NIH, 10 years instead of five. Tick bite research is hot. Platt's Mills is a giant in the field of allergy research. Some of his early work was on the connection between asthma and dust mites. More recently, he and his team have found that getting bitten by the Lone Star tick can trigger an allergy to a sugar molecule called alpha-gal, which is found in the blood of mammals, which means the tick bite can therefore render a person allergic to red meat.

55:35As Platts Mills said, tick bite research is hot. that Congress voted$100 million for it so that we can get tick-bite-related grants for different aspects of our research. And that's been tremendously helpful. Why do you think ticks are such a good selling point for voters, Congress, etc.? Just because it's relatable. Oh, come on. God had finished making the earth, and then the devil reached over and sprinkled ticks all over it. You know that. No, ticks are very interesting. The deer are absolutely infested with ticks. It is not unusual for hunters to shoot one of our deer and find the thing with so many ticks they couldn't possibly count them.

56:22When you were embarking on the research about the alpha-gal red meat allergy related to ticks, did your colleagues think or maybe even say that you were bonkers? They always say I'm bonkers. No, no, I've got away with murder several times. My father taught us that if we think A and the rest of the world thinks B, that is formal proof that A is correct. Being educated in an environment like that is really extraordinary. It does strike me, and I'd love you to tell me if I'm wrong, but my sense is that when it comes to allergy, the pharmaceutical side of the equation is doing very well. There's a lot of money being made selling treatments that may or may not work.

57:13But on the research and the public health side of the equation, plainly not nearly as robust. And I'm curious why it would be in a case where if you think of just supply and demand, there's plainly a lot of demand for allergy remediation and so on. The public would like to know more, to suffer less and so on. If the split I'm describing is accurate, why do you think there is such a big split? Because the public doesn't decide which grants get funded. The trouble is that the drug companies are so powerful and they advertise so much that people just get the idea that that's what it is. And actually, the guidelines are warped.

57:55I've been on a guideline panel for asthma where we were told that we should focus on large controlled trials published in the last five years. Well, that basically means drug studies. The number of large controlled trials of tick avoidance that are being done is zero. No one could afford to do them. Companies have a lot of money and they do big, well-controlled trials, some of which are really important. But many of which are me too. Or trying a new drug, which is a very tiny variant of the previous. It's much more important to try and understand what's happened. And I've written a history of food allergy.

58:38And there are three forms of food allergy, which are peanut and the other allergens that cause immediate hypersensitivity, eosinophilic esophagitis, and the alpha-gal syndrome. And why I pull those apart is because they're mechanistically completely different, causally different, and the reasons why they've increased are different. Peanut is probably ridiculous washing of the skin with detergents. EOE, we've just published a hypothesis that the processing of milk is a major part of that. Instead of pasteurizing milk at 84 degrees centigrade, all the milk you drink is heated to 135 degrees centigrade.

59:24It's dead, and it's homogenized, which means the particles are all changed, so they're much smaller. and we say weaponized to immunize the esophagus. And the third one, the alpha-gal syndrome, we believe is primarily due to the loss of dogs in the suburban areas. What happened in the early 80s is leash laws and now the dogs can't get together to drive the deer out. And so we all have a herd of deer on our lawn and the deer are covered with ticks. This connection that Platts Mills has drawn between leash laws and a boom in the tick population is not his only unusual theory. I was very well known in the 70s for saying that television had had a major effect on asthma.

1:00:14We published a paper in which we showed that if people watched a screen, they took less deep breaths. If they're reading a book, they still breathe normally. If your child is watching television and you touch their shoulder, they actually jump slightly because they're in a trance. They're not unconscious, they're not asleep, but they're in a trance. And during that time, the hypothesis was that that prevents their breathing and the deep breaths are a better bronchodilator than albuterol. What's happened since then, if you want something really silly, is the children are no longer watching television because they've got cell phones.

1:00:56and the cell phones don't put them into a trance. And asthma has actually become less of a problem. The asthma doctors will be horrified if they hear anyone suggesting that asthma is anything but the total problem. But actually peanut allergy has become more of a problem than asthma. But a totally different causal mechanism, yes? Totally different, yes. What are your views on celiac disease and gluten allergy? Yeah, Gideon Lack, who did the LEAP study, has been looking at celiac and seeing whether natural exposure to wheat in early childhood would prevent celiac disease. And I think he's got some evidence, but it's not of a level comparable to the LEAP study.

1:01:43The LEAP study was a tremendous breakthrough. This LEAP study, that stands for Learning Early About Peanut Allergy, was published in 2015 by the pediatric allergist Gideon Lack. It argued that feeding peanuts to babies will actually reduce their risk of a peanut allergy. Much of the evidence came from Israel, where babies routinely eat bamba, a puffy peanut butter flavored snack. Full disclosure, some adults also love Bamba. Given what we've been hearing about allergies these past few decades, especially peanut allergies, you can imagine that many parents would be terrified to let their baby get anywhere near a peanut snack.

1:02:28Once a conventional wisdom is established, it can be hard to dislodge, which gets us back to the allergy with which we began this episode. A whole generation of doctors were trained thinking that penicillinology was very dangerous. And very common. And very common. And it isn't. When I got here in 82, I already was saying things that, no, you don't need to worry about it as much as this. You need to ask the question and take precautions and be sensible. If someone had no history in 15 years, the chances that they're penicillinologic are very small. So what are some solutions? Can you talk about clearing people of penicillin allergy, for instance?

1:03:11By the way, the reason we're doing this episode is this is something that happened with me. I was told as a child I was allergic to penicillin. I avoided it for approximately 50 years. My current doctor, she said, you know, we should test. So I did. And you were negative. I was negative. But I had to go through this, you know, two-day, first the test and then the challenge test, where you actually get a little bit of it. And it's plainly something that's not scalable right now. So I'm curious what you think are solutions. I'm waking my head. People have been trying for a long time. I can't tell you how many of the residents who apply for our fellowship have been doing a study on delabeling penicillin.

1:03:54So this is not something that people are ignoring. Can you explain why it's so difficult? because as much as medical technology has changed, I mean, everything from time-release medicines to the mRNA vaccine, I mean, there's so much technology that has accelerated discovery in medicine. Why is it so hard in this case to come up with a, let's say, cheaper, faster, more scalable way to clear people? Well, there's quite a lot of literature that says you can't quite rely on a blood test. And that's what we should have, is a simple blood test for IgE to penicillin that absolutely solves the problem.

1:04:39Kimberly Blumenthal is one of the people who has been working on a better blood test for penicillin allergy. We were trying so hard. I was working with Thermo Fisher Scientific. They have developed a blood test panel, and they wanted to see if it worked in allergic individuals from America. We identified in the Boston area everyone that reacted to penicillin in front of our faces in the last few years. We sent them the blood of these individuals. And I think it picked up like three. It was like three of 20. It didn't pick it up yet. What makes it so hard? The conclusion was, well, they were allergic in the last five, ten years.

1:05:21Maybe they weren't allergic now. So I have to bring them back. retest them. And then these patients, they're like needles in haystacks, right? We combed the records of all Mass General Brigham to find these 22 penicillin allergics. We really need to say, okay, you reacted to penicillin in front of my face today, grab your blood, and then send it to be able to know that they were true positives. But you're making progress, it sounds like. Slowly. I mean, by the time you're 600 years old, this problem will be solved. One of my mentors said to me, if you do your job well, you have no job. And I'm like, I just don't think that's going to happen.

1:05:59There's always something else. We need better tests now, back to the basic science in the lab. And then on the population level, we're thinking about implementing penicillin allergy evaluation in primary care. We just created a measure of delabeled patients in our health care system. And even just now that I can measure it, I can measure it in this clinic. and that clinic, and I can see what types of interventions move the needle towards a higher percentage of delabeled patients. So what would your message be to anyone who believes that they are allergic to penicillin now? Get tested. Get tested.

1:06:39If we were to jump ahead 20, 30, 50 years or something, I would imagine that given the benefits of gene sequencing and machine learning and artificial intelligence that would be pretty simple at birth to either understand everything that a given person might be susceptible to allergy-wise or just correct it. I think it's possible. And it's also possible that we could alter our drugs to be less allergenic. How would you do that? Oh, goodness. We'd have to know what metabolite of the drug is forming bonds in our body to make the allergen. And so it requires a lot of combined intelligence from different people.

1:07:20I realized, though, as I asked that question that it's a little touchy for you because I'd be putting you out of business. You OK with that? Yeah, I would stop happy if we have some sort of way that like everybody knows if they can or cannot have penicillin or any drug or they're going to be allergic or not. If we were able to correct the 30 million mislabels in just America, I'm happy. I'm retired. And you just open a florist shop or something like that and be okay? I do like floral design. Well, there you go. I would like to thank Kimberly Blumenthal for the good conversation today, as well as Thomas Platts Mills, Teresa McPhail, and Alina Resnick.

1:08:00Thanks also to Dr. Resnick for clearing my stupid penicillin allergy label. And thanks to Becky Kurth, Dr. Deb Jones, Dr. Lene Hurst, and all the other medical professionals who helped turn me from a bone-tired coughing machine into, well, back into me, I am grateful. Making this episode was a good reminder of how much I love physicians, their drive, their curiosity, their willingness to admit what they don't know yet, and then to work ridiculously hard to find out more. We reached out to Dr. Blumenthal to see how she's been doing since we spoke with her in 2024. She wrote, I have had so many people come into my office to tell me that after hearing this episode, they knew that they should be tested for penicillin allergy.

1:08:48They never felt confident in the diagnosis, yet had said they were allergic at countless healthcare interactions over their lifetime. One young woman, she wrote, came to me after being prescribed clindamycin for a dental infection and that had led to a lot of problems with her GI tract. And she was very grateful to leave my office delabeled and able to take amoxicillin next time. That's it for today's episode. Also, we have just launched a new show in addition to Freakonomics Radio. It's a video talk show called Better in Person. And I think you will love it. If Freakonomics is about how things work, better in person is about how people work.

1:09:29You can watch it on the Freakonomics YouTube channel. I do hope you will watch it and leave adoring reviews and tell all your friends, you can even tell your enemies. And we will be back right here next week with a new episode of Freakonomics Radio. Until then, take care of yourself. And if you can, someone else too. Freakonomics Radio is produced by Renbud Radio. You can find our entire archive on any podcast app. It's also at Freakonomics.com where we publish transcripts and show notes. This episode was originally produced and updated by Dalvin Abawaji. It was edited by Gabriel Roth and mixed by Eleanor Osborne.

1:10:06The Freakonomics Radio network staff also includes Augusta Chapman, Ellen Frankman, Elsa Hernandez, Ilaria Montenacourt, Jake Loomis, Jeremy Johnston, Mandy Gorenstein, Pete Madden, and Tao Jacobs. Our theme song is Mr. Fortune by The Hitchhikers, and our composer is Luis Guerra. As always, thanks for listening. Is that Farside? Farside. It sounds like you spend as much time with comics as you spend in the lab. Of course that's true.

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