Episode transcript
Time stamps
0:00 Intro
1:23 Alpha Gal Syndrome, Milk, and Beef Allergy
3:11 GI Symptom Overlap with Alpha Gal in a Young Child
5:26 Shrimp Exposure Through Breast Milk Leads to Anaphylaxis
8:25 PR10 Sensitization Leads to Severe Reaction Peanuts
12:10 Peanut Allergy from Blood Transfusion
15:01 Fatal Anaphylaxis from Kissing
18:07 From Beer to Malt Balls: Lipid Transfer Protein Syndrome
22:30 Scombroid Poisoning Mimicking Fish Allergy
25:14 Diagnosing Dog Allergy Through Ratios
Transcript:
Announcer:
ImmunoCAST is brought to you by Thermo Fisher Scientific, creators of ImmunoCAP™ Specific IgE diagnostics, and Phadia™ Laboratory Systems.
Gary Falcetano:
I'm Gary Falcetano, a licensed and board-certified PA with over 12 years experience in allergy and immunology.
Luke Lemons:
And I'm Luke Lemons with over six years experience writing for healthcare providers and educating on allergies. You're listening to ImmunoCAST, your source for medically and scientifically-backed allergy insights.
Hello, welcome to ImmunoCAST. This is part two of an episode in which Gary and I are on location at the American College of Allergy, Asthma and Immunology. We are going over some medically challenging case studies that were presented at the college. The episode before this, we go over some really cool research abstracts so if you haven't listened to that, definitely listened to that episode. There was so much research, there was so many interesting case studies put out. Gary and I kind of boiled it down to some of the ones that we thought-
Gary Falcetano:
That we found interesting.
Luke Lemons:
Yeah, yeah, definitely. We hope that our listeners find interesting as well. So should we just get into it?
Gary Falcetano:
Yeah. There were hundreds of medically challenging cases that were presented here and we just cherry-picked a few that we found interesting, so let's do it.
Luke Lemons:
Yeah. So the first one we're going to be talking about is titled Child with Milk and New Beef Allergy Coexisting Allergies or Alpha-gal Syndrome.
Gary Falcetano:
So this is a patient, a 10-year-old male who presents with multiple food allergies. He had allergies to milk, tree nuts, sesame, the past six months, started having reactions that they were relating to beef ingestion.
Luke Lemons:
And so we know that up to 20% of children with cow's milk allergy may react to beef so it's not uncommon that if a child does have a milk allergy and they start eating beef, one may assume that they have a beef allergy. But what did they find here?
Gary Falcetano:
Yeah, so we've talked about Alpha-gal Syndrome in the past and we also talked about the CDC report that said a lot of providers were actually unaware of it still, even with all the publicity in the news. So these providers were aware of it and on deeper inquiry with the patient's parents, they found out that he had two tick exposures. And remember back to our Alpha-gal episode, Alpha-gal Syndrome is caused by bites from, we think a lone star tick, but we know a lone star tick, but certainly maybe potentially a lot of other vectors as well. And this kid had two tick bites. And so that really kind of changed their diagnostic approach besides testing as you would for all the implicated foods that he was having potential reactions to, they also tested for Alpha-gal.
Luke Lemons:
And they actually were able to diagnose him with Alpha-gal Syndrome. And the takeaway here, and they lay it out very clearly in their discussion, that when evaluating beef allergy in patients in milk-allergic children, a co-allergy and Alpha-gal Syndrome should be considered. So yes, it may be beef allergy, however you have to consider Alpha-gal Syndrome as well. When we think of Alpha-gal Syndrome, sometimes people will assume anaphylactic shock, but this is another case where it's just GI.
Gary Falcetano:
Exactly. And we've seen that increasingly as people now are looking, we're seeing isolated urticaria or isolated GI symptoms. Our colleagues from the AGA, the gastroenterologists, they actually have a clinical recommendation out now for IBS. So if you have unexplained irritable bowel syndrome, you really should be thinking about potentially assessing for and testing for Alpha-gal Syndrome.
Luke Lemons:
And in another medical case study around Alpha-gal Syndrome titled Diagnosis of Alpha-gal Allergy in Two-year-old boy with Chronic Diarrhea, they also uncovered that Alpha-gal was the issue in this child's symptoms.
Gary Falcetano:
And they don't mention in this case tick bites.
Luke Lemons:
No.
Gary Falcetano:
And I'd like to have spoken with the presenters on this just to exactly see if they had explored that. I'm sure they did, but it just didn't get mentioned in the abstract. But this is a young child, this is a two-year-old who we typically do not think as the ideal candidate for having Alpha-gal Syndrome.
Luke Lemons:
So in the study that we were talking about before, it was a 10-year-old, this is a two-year-old that was having, again, symptoms, abdominal pain, and there was a lot of procedures and a lot of testing that went into trying to uncover-
Gary Falcetano:
Because they weren't looking for Alpha-gal initially, right?
Luke Lemons:
They weren't looking for Alpha-gal Syndrome. And the takeaway here was that it should be considered, no matter the age of the child if it's unclear what's causing these symptoms so it was a two-year-old, again who was diagnosed with Alpha-gal. And we will have in this episode's description, a link to our page where you can listen to that Alpha-gal episode that Gary and I are alluding to.
Gary Falcetano:
Yeah, this patient had symptoms for a long time as part of his two-year-old life. He had symptoms for 15 months of those two years.
Luke Lemons:
And at one point in this study, they actually advise against dairy. And so for 15 months the child wasn't eating dairy because they thought maybe it's a milk. That's very common.
Gary Falcetano:
Certain people do react to milk when they have Alpha-gal Syndrome because there is small amounts of Alpha-gal in milk. So it may have been helping, but it certainly wasn't curing or eliminating the symptoms because he was ingesting other forms of mammalian.
Luke Lemons:
Exactly. And I mean even after those 15 months, there were still symptoms. And so again, Alpha-gal awareness out there, if you're listening, definitely.
Gary Falcetano:
Yeah, definitely keep it in your [inaudible 00:05:26] differential, for sure.
Luke Lemons:
Yeah, keep Alpha-gal in mind. But transitioning to something non-Alpha-gal related, this was, in my opinion, probably one of the most interesting in our slot. It's around anaphylaxis after shrimp exposure through breast milk.
Gary Falcetano:
So keeping in line with our really young children. So this was a 10-month-old boy who had atopic dermatitis. He had started having acute urticaria reactions and shortness of breath during breastfeeding. So we always talk about going back to the history and trying to figure out what could potentially be causing symptoms. Here, we had to go back because he's exclusively being breastfed, you have to go back to the mom's dietary history and based upon the history of what she was eating and how it was directly related to symptoms in the child, they really suspected several things, especially was it shrimp Alfredo that she had?
Luke Lemons:
Yeah, so she had eaten shrimp Alfredo, and then the 10-month-old began to react after breastfeeding. And so the providers, they went in and they tested and she showed elevated levels of sensitization to shrimp, wheat and cow's milk.
Gary Falcetano:
And it's important that we talk about the levels here because we have another spoiler alert. There's another part of this case study that's really interesting. So her levels to shrimp were 19.1 shrimp IgE. Her wheat was 26.8 and her milk was greater than 100.
Luke Lemons:
Yes. And so this study takes a turn because the patient wasn't counseled on these results. She had taken into interpreting her own.
Gary Falcetano:
Yeah. We're not sure whether she was just able to get the results before having a conversation with her provider or they just didn't offer interpretation. But regardless...
Luke Lemons:
She looked at the results.
Gary Falcetano:
She took it into her own hands.
Luke Lemons:
And she saw, she goes, "Oh, okay. I'm over 100 for milk. Oh, shrimp is the lowest. Shrimp is probably fine for me to eat."
Gary Falcetano:
But she continued to avoid the milk and the wheat.
Luke Lemons:
Yes.
Gary Falcetano:
But thought, okay, because the shrimp IgE was the lowest, I'm going to try eating that. And then what happened?
Luke Lemons:
She had just two shrimps and it resulted in the child going into a reaction [inaudible 00:07:36].
Gary Falcetano:
Anaphylaxis requiring Epinephrine, emergency department visit.
Luke Lemons:
And so the story here, in my opinion, the takeaway is the importance of going over test results with patients and letting them know just because you have one low level of a certain allergen for sensitization doesn't mean that's a safe one to eat or be around in general.
Gary Falcetano:
And any dietary changes, whether it be additions or deletions, it should be really be done in conjunction with the clinician, especially one who's very knowledgeable in food allergy. We do know, kind of getting back to the transmission of allergens in breast milk, we've seen other allergens like peanut, soy through breast milk. There's been case studies on that. I think this was the first case study of shrimp transmission through breast milk.
Luke Lemons:
Yeah, that's what they say.
Gary Falcetano:
So that's another reason why they published it.
Luke Lemons:
Yeah, very interesting study, our case study. The next one we're going to be talking about is called When Peanuts and Birch Pollen Cross-react, An Unexpected Reaction in Pollen Food Allergy Syndrome. So pollen food allergy syndrome, why don't we talk about that for just a second?
Gary Falcetano:
Yeah. I mean, we've discussed this before, but it really merits a quick review. So we know that there are proteins in pollens and proteins in plant foods that are very similar. And when you're sensitized to certain proteins in a pollen, they cause you to have a positive test result when you're testing for those plant foods, when you're testing for IgE sensitization to the plant foods. The most common and most one people is most aware of is a birch peanut reaction so you're sensitized to birch tree pollen. You therefore have sensitization to a very similar protein in the peanut, and that can sometimes be asymptomatic, so no clinical allergy, or you can have this pollen food allergy syndrome, which is a localized reaction right to the mouth, the oropharynx. But because PR-10 proteins are generally denatured by stomach acid, we tend to not have systemic reactions when we're only sensitized to these PR-10 proteins that we call Bet v 1 homologues the other name for them. But it's these pretty benign in general proteins.
Luke Lemons:
And to go back to what you're saying about yeah, systemic reactions, it's 8.7% of cases of pollen food allergy syndrome result in that. It's very rare. However, in this case, this patient, this 60-year-old man had some roasted peanuts and 30 minutes later had a severe reaction. And so one might assume peanut allergy, right?
Gary Falcetano:
So yeah, he had never had a food allergy before and so this was his first real presentation for food allergy. You would assume 30 minutes after eating. It's a peanut allergy. When they tested him, they actually tested him for both the whole allergen and the peanut components, as well as some additional tree nut components. It looks like they were kind of assessing for tree nut sensitizations as well here. And what they found was he also tested him for birch pollen.
Luke Lemons:
Yes.
Gary Falcetano:
These were pretty astute clinicians who on the history also saw that he had some environmental symptoms, and his birch pollen, Luke, was over 100, the PR-10 protein, so Ara h 8 in the peanut is the PR-10 protein, that was basically 100, 99.9.
Luke Lemons:
Yeah, a lot.
Gary Falcetano:
Right. And then his Cor a 1, as you remember from past episodes, the Cor a 1 is the PR-10 protein in hazelnut. His Cor a 1 was greater than 100 as well. So he had super high levels of all these PR-10 proteins and no detectable storage protein. So Ara h 2 and Ara h 6 were both undetectable.
Luke Lemons:
And if you're interested in learning more about these kind of components, we have some great component episodes in the past and a tree nut specific one, which talks about the Cor a 1 protein.
Gary Falcetano:
Yeah, for sure. I do want to emphasize that almost always, these are benign sensitizations.
Luke Lemons:
Yes, yes.
Gary Falcetano:
At most, causing some pollen food, oral allergy type symptoms. In this case, he had a systemic reaction. So we do have to be just moderately careful when we see [inaudible 00:11:35] especially patients at this level. You're right. You said it all adds up.
Luke Lemons:
Yeah.
Gary Falcetano:
Chances are he hadn't had reactions in the past. Maybe he'd never eaten peanuts during birch pollen season. Maybe that's what happened here.
Luke Lemons:
Or maybe it was a bad birch pollen season. There's all these variables. And so when providers are, if you're listening and if you do testing with allergen components, just consider the cross-reactivity between these different components. And also, again, things add up.
Gary Falcetano:
Yeah. The birch pollen sensitization on top of the peanuts may have pushed them over. We don't know.
Luke Lemons:
Yes.
Gary Falcetano:
For sure. Okay, let's move on to our next peanut case.
Luke Lemons:
Yes. So this one is called Anaphylaxis After Peanut Ingestion, Possibly Secondary to IgE Transfer from Packed Red Blood Cell Transfusion.
Gary Falcetano:
PRBC.
Luke Lemons:
Yes. This patient received two PRBCs and was in the hospital and had a peanut butter sandwich and had a reaction. They had never had a reaction to peanut prior to this. And so there was this question, what caused this random reaction? Well, I actually had a chance to talk to the author of this.
Gary Falcetano:
You did?
Luke Lemons:
Yes. Yes. They informed me that it was actually the blood bank worker who found out that the first pack of blood came from a patient who had a food allergy to peanut.
Gary Falcetano:
So I don't believe they asked for food allergy history when you're donating blood. Is that correct?
Luke Lemons:
No. No, but we don't really know why. I should have inquired more on how-
Gary Falcetano:
Maybe they went back to the blood bank to see if they could out more about the donor.
Luke Lemons:
It was a blood bank worker who found out about this, but unknown because food allergy isn't necessarily asked when donating blood. But this is interesting because this allergy was transferred to another patient, and it's worth noting that they tested them right after this reaction, and they showed elevated levels to peanut IgE, and then six months later, they tested them again and it was decreasing. And so-
Gary Falcetano:
I think they said peanut IgE as well as Ara h 2.
Luke Lemons:
Yes, yes. So the only peanut component that popped up was Ara h 2, which is a transfer protein, correct?
Gary Falcetano:
Storage protein.
Luke Lemons:
Storage protein, yes, yes.
Gary Falcetano:
[inaudible 00:13:43] storage protein, right?
Luke Lemons:
Yes. And so it's just really interesting to think that this patient had not had a peanut allergy one day and then developed a peanut allergy.
Gary Falcetano:
So I think what's interesting about this, Luke, is the first case of packed red blood cell or blood transfusion related transfer of sensitization between patients. We know that passive transfer of sensitization was demonstrated as far back as 1919. We've also seen case studies where solid organ transplant patients develop allergy after an organ transplant from a donor who was food allergic. But this is the first case of blood transfusion. So I don't know, maybe we need to look at maybe altering those blood donor forms to include a history of food allergy.
Luke Lemons:
Yeah. Yeah. I mean, another just little tidbit about this is the first blood pack that was administered was 24 hours before the reaction.
Gary Falcetano:
So the first unit of PRBC was 24 hours before the reaction.
Luke Lemons:
And then they received the second PRBC and then later after that, they were eating a peanut butter sandwich. And so yeah, it's just a really interesting case study.
Gary Falcetano:
So it was a rapid sensitization.
Luke Lemons:
Yeah, it's super interesting. The next one we're going to talk about, we've discussed this sort of thing before, but this one is titled Drugs and Kisses, Fatal Anaphylaxis Following Marijuana, Smoking and Shellfish Exposure by Kissing.
Gary Falcetano:
This is a really sad case because it is a fatal case. This is a 26-year-old female who, and we saw this in our other after dark episode on intimacy and food allergy. This patient had uncontrolled severe persistent asthma, which we know puts you at risk, right?
Luke Lemons:
Yeah, boom. Red flag.
Gary Falcetano:
For certainly more severe forms of food anaphylaxis for sure. So she had this severe persistent asthma and food allergies, multiple food allergies, shrimp, peanut, tree nuts, fish, sesame. She developed shortness of breath, progressed to diffuse parotitis, periorbital swelling, tongue swelling. She lost consciousness within 30 minutes of eating takeout food. But that takeout food didn't have any known allergens.
Luke Lemons:
Yeah. Well, her takeout food didn't. So where this is interesting is that her boyfriend at the time had shrimp in his takeout food, and they had been smoking marijuana and they had kissed, and this caused this reaction. So we already have with smoking marijuana, the researchers suggest that when the onset of the reaction started, it may have been just attributed to their smoking marijuana and the shortness of breath could be associated with that. She has asthma, so it's not far-fetched to think that she's like, "Oh, I'm just because of the smoke." But she was going into anaphylaxis because of this kiss and exposure of shrimp.
Gary Falcetano:
And I think they go on to say she did not have an epinephrine auto-injector with her.
Luke Lemons:
Yes, she did not. No.
Gary Falcetano:
So the boyfriend called 9-1-1, paramedics came. They went through a full resuscitation. She continued to have resuscitative efforts in the hospital, including ECMO, pretty dramatic. And they did not have success and she ended up being declared brain-dead.
Luke Lemons:
And it's just a terrible case. And we talked about this in the episode that you had referenced around intimacy and food allergies, just the importance of patients that you do have who have food allergy, having that conversation, what does intimacy look like with food allergy? What are things that you should let your partner know when you have food allergy? What are potential risks? Because in that episode, which we'll link in this episode's description on the page, it's not just kissing. There's a lot of other ways that people can be exposed to allergens that they're allergic to. And it's also worth noting that this study does say it's only 1% of hospitalizations are estimated.
Gary Falcetano:
That actually have a fatal outcome, right?
Luke Lemons:
Yeah. So again, we don't want to say, I don't want to act like this is a scary, scary, scary thing for other people who are listening.
Gary Falcetano:
We recently recorded a podcast here with Dr. Golden.
Luke Lemons:
Dr. Golden does a great job of explaining this.
Gary Falcetano:
That death from anaphylaxis is very, very infrequent, but it does occur and especially occurs in the setting of increased risks like uncontrolled asthma. So we need to really be more preemptive patients and really advising them that they do need to take their risks seriously, make sure they're always carrying their epi auto-injector, using it at the first sign of symptoms, not waiting. And again, when you're using mind-altering substances, it can affect your judgment and the potential response to symptoms.
Luke Lemons:
And then they say here in the discussion that coinciding recreational drugs can increase the likelihood of accidental allergen exposure so let's think about that. If they're sharing, let's say a joint or something, pass it back and forth. If he's eating shrimp, there's exposure there. And then to your point, masks or at least symptoms.
Gary Falcetano:
Exactly. Whether it masks it actually physiologically or just because you don't appreciate those symptoms. Either way, it's an issue.
Luke Lemons:
Going into another anaphylaxis case study, medically challenging case study, this one is related to beer as an initial presentation of lipid transfer, protein allergy. And Gary, I just know that you really like lipid transfer protein conversation.
Gary Falcetano:
I have. I love, one of my favorite allergens or the allergen families is the lipid transfer proteins. We've discussed this in the past, but lipid transfer sensitization, the transfer protein sensitization and allergy wasn't so common in North America, in the U.S., Canada, but it's actually fairly frequent in the southern Mediterranean, in southern Spain and Italy. We're starting to see more and more LTP syndrome, meaning patients that are sensitized to multiple lipid transfer proteins in various foods in North America, in the U.S. so I think it's something we need to be certainly more aware of. So tell us about this case.
Luke Lemons:
Yeah, so what's interesting about this is it's a story of lipid transfer proteins in this patient.
Gary Falcetano:
Almost a journey.
Luke Lemons:
A journey. And it starts as the title suggests with beer. So at 22, they had a beer and they went into anaphylaxis from that beer. Going forward, they experienced reactions to peanuts, to tree nuts, cannabis as well there was reactions. It's notes here. They first tried cannabis in their twenties, and then in their thirties they started noticing itchy mouth related to peanuts and tree nuts, also eating malt ball at Christmas parties, which is talked about in here as well, that they-
Gary Falcetano:
I'm not sure what a malt ball is, but it [inaudible 00:20:00] sounds like it has malt like we used to make beer, right?
Luke Lemons:
Yes, yeah. This whole time, all these different food allergen exposures that are causing reactions. But what they ended up finding, Gary, was that...
Gary Falcetano:
Yeah, I mean they did pretty extensive evaluation and they found that he had elevated levels of IgE to both peanut, walnut, hazelnuts, pistachio, hops, barley, malt, soy and wheat. Then they took a deeper dive with the allergen components and when they assessed all the available allergen components to whichever of those whole allergens that we had components available to, they found that he was exclusively sensitized to lipid transfer proteins. So this was a lipid transfer protein syndrome patient again, in North America becoming increasingly common.
Luke Lemons:
In the discussion, they say in Europe it's more common to recognize lipid transfer protein syndrome. But like you had mentioned earlier too, it's becoming more and more and more of a common thing. And so the takeaway here, what would you say for our providers listening?
Gary Falcetano:
So I mean, you need to always have your index of suspicion high when you're seeing allergic reactions to multiple foods, especially when those foods all have a common protein family, like the lipid transfer proteins. We also know, and back to our cannabis allergy episode, that there are lipid transfer proteins in cannabis. And that can certainly either initiate a sensitization or cause a patient to react to other LTPs afterward, or a food allergy LTP sensitization can cause you to react to cannabis. Go both ways.
Luke Lemons:
And when doing testing for food allergies, just testing with allergen components to understand this is the protein or this is the molecule that is causing reaction and it so happens to be a lipid transfer protein. Oh, that's interesting. And then looking at the other reaction that they may have to certain foods or other substances.
Gary Falcetano:
Exactly. And I don't want to mislead our listeners that the cannabis LTP, while we know it exists, it's available to researchers, it's not available for regular use right now in the U.S.
Luke Lemons:
Yeah, cannabis is not, but with other food allergies, yeah.
Gary Falcetano:
There are multiple lipid transfer proteins for the foods that are available.
Luke Lemons:
And we'll link in this episode's description to the lab ordering guide, which has these profiles from labs in your area or labs that you want to use that have these allergen components that you can definitely utilize in your practice. So again, you love LTP syndrome. We're going into another topic that you always introduce. This is another.
Gary Falcetano:
You would think my life just revolves around interesting allergies, don't you?
Luke Lemons:
I know LTP syndrome. I know what, is it pistachio or is your favorite allergy-
Gary Falcetano:
Cashew.
Luke Lemons:
Cashew is your favorite-
Gary Falcetano:
Ana o 3.
Luke Lemons:
Yeah. Is your favorite allergen component. And then also scombroid poisoning, which is what's going on in this one.
Gary Falcetano:
So we discussed this in our food intolerant episode, right?
Luke Lemons:
Yeah.
Gary Falcetano:
Really interesting. Where someone who ingests, especially large fish like mackerel, tuna that has started to age a bit, was not kept at optimal temperatures. The fish itself develops histamine or histidine that converts to histamine and then we ingest the histamine and we have what looks like a full food allergic reaction, but it's not IgE mediated. We're just ingesting histamine that's causing symptoms. That's the whole scombroid poisoning syndrome. So the title of this article is Scombroid Poisoning Mimicking IgE Mediated Fish Allergy in a Patient Using Phenylzine, an MAO Inhibitor.
Luke Lemons:
Yes.
Gary Falcetano:
So that's what's different. We know about Phenylzine, an MAO Inhibitor poisoning, but I haven't seen this take. So in this patient, they had a much more severe reaction because they were taking an MAO inhibitor. And we know MAO inhibitors prevent the degradation of histamine in the gut.
Luke Lemons:
Yes. Within this study, it was a 29-year-old female and they had no history of food allergies, but they developed whole-body flushing, swelling and lightheadedness, nausea 30 minutes after mahi-mahi ingestion. So again, a provider may start there, fish allergy maybe, right?
Gary Falcetano:
Right. No, exactly. So I think you always have to keep in the differential.
Luke Lemons:
Exactly.
Gary Falcetano:
If this was a new onset fish allergy, they haven't had any issues in the past, is it just because they got bad fish and not because they actually have a true clinical allergy?
Luke Lemons:
And in this case, it was the scombroid poisoning and because of the MOA inhibitors, actually it made it more [inaudible 00:24:27] severe reaction.
Gary Falcetano:
Well, I think that pretty much concludes our cases for today.
Luke Lemons:
Yep. We have no more, Gary.
Gary Falcetano:
Can we please talk about my poster that I presented?
Luke Lemons:
Yes. No.
Gary Falcetano:
Come on, we have time.
Luke Lemons:
So yeah, Gary did present also here at the college and has his own paper that I will be talking about. No, I'll let you go.
Gary Falcetano:
I think I should have you talk about it. We'll see if you actually paid attention.
Luke Lemons:
I definitely did, Gary. That's why, you did it so well. So I don't want our viewers to miss out on your...
Gary Falcetano:
Yeah. Okay. All right. So this is an abstract that I presented with my Spanish colleagues, actually, Dr. [inaudible 00:25:04] from Barcelona. And because they didn't want to come to beautiful Boston and leave drabby Barcelona, they had me present the abstract at this conference.
Luke Lemons:
But it was good. It was a good presentation, all jokes aside, and I think that this is a really interesting paper that you put together, especially around pet components and furry animals.
Gary Falcetano:
So the title is Improving the Diagnosis of Furry Animal Allergies through Ratios, Lessons from a Patient Case Study. And in this we actually present a case that is a 20-year-old female who presents with respiratory allergies. She lives in an urban environment with a male dog. She has past history of pretty severe rhinoconjunctivitis. And she had previously been tested for and tested positive for dust mite allergy and actually received allergen immunotherapy that it really improved her symptoms. More recently though, she was having nighttime episodes of shortness of breath, wheezing, and she really attributed these very closely with exposure to her dog. And I think I mentioned her dog was a male dog.
Luke Lemons:
Yeah, yeah.
Gary Falcetano:
So in Spain, they do a kind of a sequential workup and they did a full workup from pulmonary function testing to blood eosinophils as well as skin testing and blood testing for whole extracts and they were looking at some of the most common. What they found was she had an elevated IgE to dog as well as still to dust mites, but pretty small level. And their next level of testing, they went to allergen components.
Luke Lemons:
Yes. What did they find there in allergen components for?
Gary Falcetano:
So what they found was that her whole allergen for dog dander was 35. Her allergen components, she was negative to Can f 1, she was negative to Can f 3.
Luke Lemons:
Which are dog components.
Gary Falcetano:
The dog components, sorry. And negative to Can f 2 so negative to the initial components they tested for. There were some newer components that they didn't test for initially. When they looked at her sensitization profile, she was positive also to Can f 5.
Luke Lemons:
Okay.
Gary Falcetano:
And remember what Can f 5 is
Luke Lemons:
Yes. Can f 5 is actually found mostly in male dogs, right?
Gary Falcetano:
Always. Exclusively in male dogs.
Luke Lemons:
Always exclusively in male dogs. And it's because it is created in the prostate.
Gary Falcetano:
Exactly. It's a prostatic [inaudible 00:27:18]. So looking at her sensitization profile, it looked like she's allergic to her male dog. Perhaps in the future when she's getting a new dog, she can look to get a female dog and not have symptoms.
Luke Lemons:
But it really speaks to the power of components here, right?
Gary Falcetano:
Well, it does, but here's the cliffhanger here, right? Here's the glitch. They said, "You know what, we should look at her ratios to see if we're missing anything." And so there was a paper done a few years ago by kind of a consensus group in Spain that looked at a new way of interpreting IgE results. And they looked at it looking at total IgE versus individual specific IgE is like dust mite or dog. And then when you get those specific IgE's looking at the ratio of their components to those to see if you might be missing something.
And what they found was that those original components that were tested for did not make up a high percentage of the dog IgE. So they said, "You know what? We're missing something." The Can f 5 was only a small percentage. So they retested for Can f 6 and Can f 6 was 53% of the dog extract.
Luke Lemons:
Wow.
Gary Falcetano:
So now the diagnosis has completely changed because we assessed for all the available dog components. We know now that she would be allergic to both male and female dogs so our advice is a little bit different going on. And we also know she's probably not going to get rid of this dog.
Luke Lemons:
Which is great.
Gary Falcetano:
So she needs to do things like keep it out of the bedroom. That's where she's having a lot of symptoms. Making sure we're doing those exposure reduction, really taking them seriously because she's having serious symptoms and she's probably a candidate for referral. I mean, these were allergists, but if it wasn't certainly to get to allergy for allergen therapy to help reduce her symptoms.
Luke Lemons:
So for our primary care audience out there, what would you say to them based on this paper?
Gary Falcetano:
Yeah, so the take-home is we assess for components whenever you see a positive dog, a cat, especially when they're both positive because it can help differentiate between them. But remember back to our pet allergen component episode, the more components you're sensitized to, the higher your risk of a more severe phenotype of disease. So it gives us additional information besides just the whole extract being positive. And in this case, it may have meant she could tolerate a female dog and not a male dog. It didn't because when we looked at all the components, she wasn't just sensitized to the Can f 5, she had other components that were positive.
Luke Lemons:
Yeah. Well, again, that's Gary's paper.
Gary Falcetano:
Thanks for the opportunity.
Luke Lemons:
And you'll be able to read all of these medically challenging case studies that Gary and I have spoke about this episode, as well as some additional ones. If you click the link in this episode's description, you'll be brought to this specific episode's resource page, and you can kind of dive in. Definitely check out, which is number M-1-1-2. Yeah, that's the-
Gary Falcetano:
Call out?
Luke Lemons:
Yeah, CTRL-F. Find that, because there's a lot of medically challenging case studies in here.
Gary Falcetano:
For sure.
Luke Lemons:
But thank you again for listening to Immunocast. We hope that you enjoyed listening to this, and don't forget to share and subscribe.
Gary Falcetano:
Yeah, it's been fun. Thanks again. We'll see you next time.
Luke Lemons:
Thank you.
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ImmunoCAST is brought to you by Thermo Fisher Scientific, creators of ImmunoCAP™ Specific IgE diagnostics and Phadia Laboratory Systems. For more information on allergies and Specific IgE testing, please visit thermofisher.com/immunocast. Specific IgE testing is an aid to healthcare providers in the diagnosis of allergy and cannot alone diagnose a clinical allergy. Clinical history alongside Specific IgE testing is needed to diagnose a clinical allergy. The content of this podcast is not intended to be and should not be interpreted as or substitute professional medical advice, diagnosis, or treatment. Any medical questions pertaining to one's own health should be discussed with a healthcare provider.
