Episode transcript
Time stamps
0:42 - What are Fireside Chat episodes?
1:25 - Why the allergy system threshold is important to understand.
2:14 - How do people become allergic?
3:25 - Explaining cumulative threshold disease.
5:52 - How food allergies play into the allergy system threshold.
8:40 - How to help patients reduce exposure to known sensitivities.
10:53 - Helping patients understand what they may be allergic to.
15:23 - Summarizing the key ideas from today’s discussion.
Announcer:
ImmunoCAST is brought to you by ImmunoCAPTM Specific IgE testing and PhadiaTM Laboratory Systems, products of Thermo Fisher Scientific. The content of this podcast is not intended to be and should not be interpreted as a substitute for professional medical advice, diagnosis, or treatment. For patients any medical questions pertaining to one's own health should be discussed with a healthcare provider.
Gary Falcetano:
I am Gary Falcetano, a licensed PA with over 11 years experience in allergy and immunology.
Luke Lemons:
And I'm Luke Lemons, with over five years of experience writing for healthcare providers and educating on allergies. You're listening to ImmunoCAST, your source for medically and scientifically backed allergy insights.
Today we've got a really interesting episode for you. We're doing a fireside chat around symptom threshold. This is the first fireside chat episode that we've done. And to give our listeners a little bit of background on what that means, with ImmunoCAST we've divided a lot of our episodes into four different buckets, and fireside chat is one of them. And any episode you see with fireside chat in the title means Gary and I are going to be talking about a very specific part of allergies, and we are going to just give a little more detail. It's not going to be as clinical as a curbside consult episode that you may have seen. So today we're going to be talking about the symptom threshold when it comes to allergies.
Gary Falcetano:
So I've been doing a lot of thinking about the symptom threshold and how it sometimes I think is either not thought about or partially misunderstood by clinicians, and also how understanding it can really help improve patient's understanding of their disease and how to manage it.
Luke Lemons:
And with allergy season coming on soon, it's a good concept to understand when you see patients and when they're coming into your clinic. And if you're a patient listening to this episode, this is just a good bit of knowledge that will help you stay more informed as you experience allergies throughout the year.
Gary Falcetano:
Exactly. And hopefully once we finish this discussion, clinicians may want to even share this episode with their patients to better help them understand.
Luke Lemons:
Yeah. So let's get into it. Why don't we start first with how one becomes allergic, because I think that's where the story starts, with symptom threshold.
Gary Falcetano:
Sure. I mean, we know allergies are kind of an atypical response to something that we really shouldn't be responding to, whether it be an environmental allergen in a pollen or a food. But it requires sensitization first. So we actually have to be exposed to an allergen. The body sees that allergen as an invader and obviously produces antibodies. In this case, we're talking about IgE antibodies, the ones that are consistent with type 1 hypersensitivity reactions.
Luke Lemons:
And this sensitization, Gary, can I be sensitized to something one week and then the next week become allergic? Or what's the timescale on that? I know it's different for food and respiratory, but can you explain a little more about that?
Gary Falcetano:
Yeah, so I think it's one of the things that I think is a little bit complex in that we can certainly develop sensitizations at any time during the lifespan, and those sensitizations may or may not cause clinical reactivity, depending on our levels of tolerance to those specific antigens or allergens.
Luke Lemons:
So when someone says that it's a bad allergy season and they're really showing out with runny nose, sneezing, itchy eyes, it may be because there's a lot of pollen. But you were mentioning when we were talking before recording this episode, something called a cumulative threshold. And that's what allergies are, a cumulative threshold disease, right?
Gary Falcetano:
Yeah, exactly. So a cumulative threshold disease, really to think about it simply, it's not just one sensitization necessarily, or one allergy necessarily that causes your symptoms. Now it may, you can certainly just have an allergy to, say, birch tree pollen, have a really bad birch tree pollen season and have pretty severe symptoms. But most people aren't like that. We know that around 80% of people who are allergic are allergic to more than one thing, and those different allergies add up and that's where we get that cumulative threshold disease, or a cumulative threshold concept from.
Luke Lemons:
And the best way that I like to understand this concept of the symptom threshold for allergies is having an empty glass. And you have on the side a bunch of other allergens, and you put a shot of pollen in, a splash of dog dander, and then maybe a little bit of dust mites, and all of a sudden the glass is overflowing. And that overflowing is when we see symptoms. And knowing that, how can somebody prevent their glass from overflowing?
Gary Falcetano:
So that's, I think, a great visualization, Luke. So if we think about that, instead of a glass, let's think of it as maybe almost a sun tea container, maybe, with a spigot at the bottom. Everybody can kind of visualize that. If we can pour off a little bit of that allergen exposure from the bottom, we can keep it from overflowing.
So minimizing exposure to the things we know we're sensitized to, and again, not putting someone in a bubble. We typically, especially when we're talking about environmental allergens, can be really hard to just eliminate them completely. But if we reduce exposure and limit our exposure to some of those things that we know we're allergic to, we can keep that glass from overflowing.
Luke Lemons:
Yeah. And before we get into some management tips, I have to ask, is the symptom threshold the same for food allergies? Is that a concept that's also with food allergies, because I've only ever really understood it with respiratory allergies?
Gary Falcetano:
Absolutely. I'm sure everyone has heard cases where someone is exposed to a trace amount of food and has a severe reaction, and another patient who has that same, say, peanut allergy, can be exposed to maybe one or two peanuts and not have a reaction. So there are different thresholds. People have different levels of tolerance and thresholds, whether it be food or environmental allergens.
Luke Lemons:
So it's less of a, allergies aren't a binary disease. It's not that you have allergies and you're sneezing a lot. It's a spectrum. And depending on that threshold, you may be reacting differently based on the amounts as well that you're exposed to.
Gary Falcetano:
Absolutely. I was going to say.
Luke Lemons:
Yeah, yeah.
Gary Falcetano:
No, I was going to say, and it's not just allergens that can change that threshold. So we know that, for instance in the fall, we can have an increase in viral illnesses or the fall and wintertime, and those viral illnesses can increase airway inflammation. Then when we have allergy on top of that, it can make you surpass that symptom threshold even faster. So it's not just allergens.
Luke Lemons:
Oh, interesting. So you're saying sometimes viruses can contribute to that as well. So you're not allergic to the viruses, but it's the symptoms itself.
Gary Falcetano:
Exactly. Because the viruses are causing inflammation in those airways. If it's upper airways with rhinitis, and then you're exposed to an allergen that you're sensitized to and allergic to, and it increases that inflammation even more and pushes you over the symptom threshold.
Luke Lemons:
Can this threshold change over time? I know that I had really bad allergies when I was a kid to pollen and mold, outside mold, and I don't have that necessarily anymore. Could it be that my symptom threshold is changing? I also don't live where I grew up. So maybe that's the case too.
Gary Falcetano:
Yeah, it could be all the above. But we definitely see thresholds change over time. You mentioned food allergy. We know that young children who are allergic to things like milk or eggs or wheat, typically develop tolerance to those by the time they reach adolescent. Not all, of course. But they certainly do. So thresholds there change.
We know that as people age, their immune responses decrease a bit. So we tend to see allergic responses follow that and decrease as we age as well. Again, individual patients can always go against that standard, but that's certainly what we see as a trend.
Luke Lemons:
Okay. And managing allergies. You mentioned earlier that reducing the amount of allergic triggers could keep somebody from going over their symptom threshold. So I know we can't live in a bubble all the time. You can't walk around your neighborhood chopping down every maple tree that you see because you have a doctor's note.
Gary Falcetano:
It's also frowned upon quite a bit.
Luke Lemons:
Yeah, it's frowned upon. It's not permissible.
Gary Falcetano:
Let's not destroy rainforests because you have a pollen allergy, Luke. Okay?
Luke Lemons:
Exactly. But there are things that people can do, and that providers can recommend patients do that can reduce their symptoms, especially with dust mites, dog and cat dander. Could you talk about a little of those?
Gary Falcetano:
Yeah, so as you said, we can't put people in a bubble, but I think once we know what we're sensitized and allergic to, then we can really focus on those things, minimize certainly our exposure. But I think one key concept to remember is having a safe sleep space. So the area that we spend eight, nine, sometimes especially with children and adolescents 10 hours a day, in this single environment of the bedroom and the sleep space. If we can protect that sleep space as much as possible. So think about anything you're allergic to that's found in the bedroom already. So things like dust mites. Things potentially like mold. If we can decrease those levels in the bedroom, that can have a positive impact on our symptoms.
On the flip side, things that are found outside of the bedroom. So pollens, we try not to bring them in, keeping windows closed during pollen season, changing your clothes before you go into the bedroom and sleep. You should never sleep in the same clothes you've been outside playing or working in. Luke, both you and I are a little follicly challenged, so this isn't something we typically worry about. But if you think about it, if you have a full head of hair and you're outside working playing, that pollen will attach to that hair and then you just put it right in your pillow and sleep with it. So it's important to shower. Make sure you get rid of that pollen before you spend time in that sleep space.
Luke Lemons:
Yeah, it's the one benefit of losing my hair earlier in life is that I don't have to worry about bringing pollen into my bedroom.
Gary Falcetano:
That, and you've really increased your swimming speed.
Luke Lemons:
Yeah, and I can run really fast now. Aerodynamic. So when a patient comes in and they have really bad allergies because let's say it's spring allergy season and over the counter medicine isn't working, or they're struggling to go about their day, what is something that you recommend being a provider yourself, or what have you done in the past to help these patients?
Gary Falcetano:
Yeah, so I think one of the things we forget about is that almost all the allergy medications, whether it be inhaled nasal steroids, whether it be the non-sedating antihistamines, they're all over the counter now. So more than likely patients have tried these and if they're coming to the office looking for assistance, they've probably already tried this.
Now we certainly can help them making sure they're taking the correct medications and utilizing them appropriately. But they really need more insight into their disease, and finding out, number one, is it allergy or not? I'm sure we'll do an entire episode on non-allergic versus allergic rhinitis. But even with allergic asthma, and we'll do another episode on allergic asthma, but knowing if the symptoms we're having are actually caused by allergic triggers or not is really important.
So phenotyping them first. Allergic versus non-allergic. And then when they're allergic, telling them exactly what they can focus on. I think for too long we've said, "Oh, there's a bunch of things that you might be allergic to based upon the season, based upon what you're telling me." And when we tell them all of that, they really don't have anywhere to focus on.
Luke Lemons:
And when it comes to the symptoms threshold, just knowing exactly what each layer could be contributing to their symptoms is so important. Because everyone wants to blame the cat. Everyone wants to blame the trees. But if somebody has a perennial allergy of dust mites throughout the year, then that might be an easy way to reduce exposure and keep people under threshold.
Gary Falcetano:
Under that symptom threshold, exactly.
Luke Lemons:
Yeah. And dust mite covers and dust mite bedsheets, all those things are easily accessible.
Gary Falcetano:
Exactly. And as you said, perennial or year-round allergens. So they're being exposed to these dust mites year round, they have this simmering level of inflammation going on, and then they have another allergen added on like a pollen, or they get a new dog that they're allergic and that really sends them above the threshold. And they're going to blame the new thing because that's what you see, that's what's visible. The dust mite is not visible. It's a great point.
Luke Lemons:
Yeah. So just make sure patients understand what they're allergic to, and that can help in managing symptoms. And of course, looking at patient history with testing as well, is the way you can diagnose a clinical allergy.
Gary Falcetano:
That's exactly right. We can't diagnose an allergy based upon testing alone or history alone. And you just reminded me of a really important thing. So as clinicians, I think, especially ones that haven't utilized testing in the past, we tend to think that a good history, a really good structured history can tell us what someone's allergic to. And there've been studies that show that that's just not the case. One study that looked at general practitioners actually saw a bunch of false positives. So we were blaming the wrong things when based upon history alone. Cats and dogs, 30% of the time we were wrong when we guessed that that's what was causing it.
Luke Lemons:
And I think I've seen that study that you're talking about, and it's what, 54% of people who think that they have or are diagnosed with tree pollen allergy because testing wasn't incorporated. 54% of people don't have tree pollen allergy, but they think that they do.
Gary Falcetano:
That's exactly right, which is why we're talking predominantly to a primary care audience. But that's exactly why specialists like allergists not only do a great history and physical, right, but then they incorporate testing to get to the diagnosis. And that's why it's recommended in all of the major guidelines. You need the two to really come up with an accurate diagnosis.
Luke Lemons:
And all that helps for keeping that symptom threshold below that limit because at the end of the day, the symptoms that we experience dictate how we go through our lives. And it's just such an interesting concept that truthfully, I didn't understand completely when I first started to learn about allergies and immunology. But it's one of my favorite fun facts, and probably not that fun. I've probably cornered too many people at a party or something talking about the symptom threshold, so.
Gary Falcetano:
But it is. It's Such an important concept, and I think we tend to forget about it for sure.
Luke Lemons:
Yeah, and this episode too, on symptom threshold, like Gary mentioned in the very beginning, could be a good patient education tool if you're trying to give a little more background on why you're recommending to a patient that they need to keep the dog out of the bedroom. Because I can only imagine how hard that conversation is that your pet can no longer sleep in your bed.
And you can find more information on the symptom threshold on this episode's page Thermofisher.com/ImmunoCAST, where we have some additional resources that you can use after testing that outline the symptom threshold for patients. Gary, do you have anything else to say on a symptom threshold before we wrap up?
Gary Falcetano:
No. I think just always keeping In mind that it's not always the obvious allergic trigger that's causing the symptoms or causing a more severe form Of the symptoms. Keeping in mind that it is a threshold disease and we need to really explore all the things that could be leading to that increased threshold, or exceeding that threshold.
Luke Lemons:
Perfect. Well, thanks for listening to ImmunoCAST. And again, don't forget to go to Thermofisher.com/ImmunoCAST for additional resources on symptom threshold.
Gary Falcetano:
We'll see you next time.
Luke Lemons:
Bye.
Announcer:
ImmunoCAST is brought to you by ImmunoCAP Specific IgE Testing and Phadia Laboratory Systems, products of Thermo Fisher Scientific. 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.
