Allergies. They can range from mild annoyance to deadly. They can be unpredictable and vary wildly from person to person. But what exactly is an allergic response? What's functionally happening inside your body? That's what we're talking about today on Hello from the Van. An allergy or an intolerance? That's the first distinction we need to make before we get too far into this episode. An allergy can be fatal. An intolerance? Yeah, not so much. The difference is in the body's immune response. An allergic reaction is an immune response to an allergen. An intolerance is generally due to a lack of an enzyme that helps someone digest food or something else in their environment. For some people, an intolerance is simply because they don't like things. This distinction between allergy and intolerance is very, very important. One can kill you, the other will give you gas. It's a big difference. Let me explain. Let's take milk, for example. When someone is lactose intolerant, their body lacks the enzyme needed to process lactose, which is in milk. If they have dairy products, their lactose intolerance can lead to indigestion, diarrhea, stomach cramps, and other issues that peptopismol or lactase can solve. A dairy allergy, on the other hand, can cause a full-body immune response that includes things like swelling, vomiting, breathing trouble, hives, and can require multiple medications to calm the body's immune system. Taken far enough, a dairy allergy can be fatal. Lactose intolerance? Yeah, again, not so much. Here's why. An allergy is when your body's immune system reacts in spectacular fashion to an antigen. Antigen is just a fancy word for something your immune system can react to. It's the label your immune system uses for potential bad guy. Remember two weeks ago when we talked about blood types and the antigen is what helps determine your blood type? It makes more sense when you think about antigens as the friend or foe, potential bad guy of your body's immune system. For some people, these antigens are peaceful. Good guy. For others, being exposed to similar antigens is destructive. Bad guy. Let's stick to our dairy allergy as the example. If you have a severe allergy to milk, your body recognizes the proteins in milk as unsafe, as bad guys. And if you find yourself exposed to dairy, your body will send out antibodies to fight those bad guys. But how do they fight it? What do these antibodies do? Well, the first thing, they send out chemicals. They deploy blood cells and start shutting down your body's systems. It's like an intruder alert for your body. Intruder alert, intruder alert, we have an antigen here. There's also something called a histamine response. The antibodies try to stop more antigens, in this case, the dairy proteins, from getting into the body. They shut everything down. If nothing is working, well, more bad stuff can't get in. That's the thinking, right? This can be manifested through swelling around your eyes and in your throat. Breathing and heart rate are slowed because if your body isn't pumping, it can't spread the antigen. Some people even vomit when exposed to their allergens, while others get diarrhea. Think of it like your body is doing everything it can to get those antigens out of its system. It's the great purge of antigens. And this purge has a name. It's called anaphylaxis. Anaphylaxis occurs when the antibody, immunoglobulin E, or in this case, we're just gonna call it IgE. That's the abbreviation used in medicine. This antibody, IgE, recognizes a foreign antigen and then attaches itself to it. IgE sounds the intruder alarm like a big bad security guard and starts off a chain reaction in your body that then results in the widespread release of chemicals, including histamine. This is what makes severe allergies so deadly. The body tries so hard to get rid of the antigens that it actually ends up harming itself. In modern medicine, scientists and doctors have found medications and chemicals that counteract and combat these anaphylactic responses. The first line of defense is a chemical called epinephrine, and it's the main ingredient in epipens. Epinephrine basically forces your body to do the opposite of what your antibodies do during anaphylaxis. For example, anaphylaxis slows your heart down and epinephrine speeds it up. A little story time here. I used to have a very, very, very, very severe dairy allergy. More on that later. The first time I had to use an epipen, I was in my 30s and was tired. In my exhaustion, I grabbed the wrong box of cereal and had a couple bites. I was now very quickly in full-blown anaphylaxis. Luckily, I lived a block from an urgent care. I ran over, the nurse nonchalantly checked me in. I said between grasps, I need Epi, but I can't do it. I knew it was life or death, and yet I could not bring myself to give myself the EpiPen injection. My brain's override system was just not having it. I would hold the EpiPen to my thigh, and I just couldn't push the button. So the nurse comes over and the doctor came out, and neither of them had ever administered an EpiPen. So there I am, suddenly finding myself lying on a gurney, literally fighting for my life while they discuss how to use the EpiPen. I am near passing out at this point. When I slowly blink and then BAM right in my thigh. Epinephrine. The scream that I scrumped. When I tell you I could have fought a bear, I literally screamed, What are you doing? You have to warn someone before you stab them. I was possessed by epinephrine. My body was on fire. It was a lot. Spoiler alert, I lived. This is not the only time I would have to use an EpiPen in my lifetime. And I gotta say, big fan of EpiPens at this house. But if this has you scared, don't be. I have since used EpiPens multiple times and it's been a uh a lot calmer experience. Most of the population of the world has things called seasonal allergies to things like pollen, dust, and mites. And yet, every spring, most people aren't needing epi pens every time they go outside. If you have the type of allergy that requires an epi pen, it actually has a name. It's called a type 1 hypersensitive reaction. There's actually four types of allergic reactions, and this is the one that most people know about. This is the most widely known because it includes anaphylaxis. Now we're going to very briefly cover type two, three, and four. Here's what you need to know these are different types of allergies. They're things that we don't necessarily think of as allergies because they are less about getting rid of the antigen and more about let's get rid of everything. Type two hypersensitive reactions are rare and normally require something called immunosuppressants. These are medications that just keep your immune system from doing the whole of its job. Type two hypersensitive reactions can be lifelong struggles, and we tend to view them less as allergies and more as diseases. Interesting, right? Remember two weeks ago when we talked about blood, and if you get the wrong blood type in your system, it can be deadly? Well, that deadly reaction is a type 2 reaction. The reason we blood type is technically due to allergic reactions to antigens. Type 2 reactions are on the cellular level and require a lot more work to get around. An example of this is something called Graves disease that affects the thyroid. We call it a disease, but it's technically a type of allergic reaction. Type 3 reactions are an inflammation response. Examples of this are conditions such as lupus and rheumatoid arthritis. Type 4 hypersensitive reactions are even more complicated because they include T cells leading the way into the inflammation fray. But that's all a little much for a single podcast. Just know that there are different types of allergic reactions and they basically all boil down to different types of antigens and antibodies. Before we go, let's answer some basic allergy questions. Can animals have allergic reactions? Yes, because they too have antigens and antibodies. Are there epipens for dogs and cats? No, not commercially available. My dog is allergic to bees. He loves a good spicy sky raisin. This has led to several visits to the doggy ER and thousands of dollars over the years. Through this, I have learned that dog allergic reactions are very different than human-led ones, in that dogs require exercise to get their allergens out of their systems. And with exercise and a raised heart rate, doggy allergic reactions can be shorter than human ones. Alright, next question: Is it possible to heal an allergy? Yes. There are exposure therapies available for common food allergens that allow some people to then go on and eat and tolerate their allergens. There are also shots that you can get to help with seasonal and dander allergies, like those to cats and dogs. Can an allergy go away on its own? Yes, but usually under very unique circumstances. I know, I am fully aware that this sounds fake. Remember that very severe dairy allergy that I had, the one that has almost killed me multiple times. Yeah, I don't have that anymore. I eat so much flip and cheese. I never did exposure therapy or shots. My allergy went away during pregnancy. During my second pregnancy, I had a dairy exposure and went into anaphylaxis. I had an ER visit and then all the medications and went on to have my baby several weeks later. After the baby arrived, I went back to a new allergist for further testing. This is standard procedure for women who have severe allergies, as you can get new allergies during pregnancy. Well, I went in to a new doctor. I had the pin prick test done. This is where the doctor pricks you with a small plastic needle and gives you the tiniest of exposure to your allergen. After waiting an allotted amount of time, this new doctor said, Are you sure you have allergies because you're having zero reactions? I assured him that yes, I definitely had a dairy allergy, as well as several other life-threatening allergies. He said, No, you don't. I said, uh no, I absolutely do. He said, No, you don't. And we continued on in this fashion for a good five minutes. I would go back for further testing over the next few weeks, only to discover that at some point during my pregnancy, my allergy had gone away. I asked the doctor if he had seen something like this before, and he said that I was the third woman he had encountered that had been through the same thing, and that all of us had had exposures to our allergens while we were pregnant. I asked him how this might happen. What was the mechanism that makes it so that I can now eat ice cream and nachos to my heart's content? He said that doctors weren't actually sure. There are theories about the baby sending out stem cells when the mother is in distress, but that nothing definitive has been determined, especially because it's very hard to run anaphylactic testing on pregnant mothers and their babies. So, yes, it is possible for allergies to go away, but no one has proven how or why just yet. Our last question is it possible to be allergic to things that we need, like water? And again, the answer is yes. And again, I know that this sounds fake. It's called aquogenic eurticaria. And there are only a handful of people in the world that have it. Less than a hundred. I actually had a friend from high school that was allergic to water. No one in college believed me when I said that I had a friend allergic to water. My life is just a stream of impossible situations. But unique allergies like this do happen. With the help of skilled doctors and a lot of medication, my friend has gone on to live a rather normal life, despite his allergy to water. He has a wife and kids and a very successful career now. An allergy is not the end of the world, even if it's an extreme one. I've said it before, and I've said it again. The human body is incredible. And with that, I'm Mimi Fotz, and this has been Hello from the Van.