The death of Ammaria Johnson is heart-wrenching for all of us. An innocent 7 year old dies at school from peanut-induced anaphylaxis because her life-saving medication, epinephrine, was not available to her. This is a grim reminder of the life-threatening nature of food-induced anaphylaxis and a very serious reminder of the critical need for massive food allergy education.
So, here’s what I am going to do. I am going to teach you what happens in your body during an allergic reaction. I want to do this for two main reasons:
1. TO EMPOWER YOU. Science is power. It’s the proof. And because food allergy is a term used relatively loosely, food allergy families and friends often find themselves feeling like they have something to prove. If you can use the words “mast cell” and “histamine” when you are describing food allergy to someone, they will have less opportunity to question you, to doubt you.
2. TO HELP YOU EDUCATE OTHERS. If you have a clear understanding of how food allergy works and why epinephrine will save the life of someone who is experiencing anaphylaxis then you can be a better and more confident educator. You will become an authority on food allergy. You’ll have the facts in your back pocket. People will listen because science is power.
I was at a kindergarten social for Sal and two fathers asked me why Gino and Milo didn’t go to the same school as my older son. I explained that for preschool we hired a teacher for the boys because they have life-threatening food allergies and we didn’t think they were ready for a traditional food-filled preschool setting. They just looked at me. I felt doubt. I felt judgment. I felt misunderstood. So instead of continuing with the normal, “So, anyway, I grew up in Bourbonnais. What about you?” conversation, I thought I would give something else a try. I asked them if they would mind if I took a few minutes to explain, scientifically, what happens during an allergic reaction. They agreed, mostly to humor me. (How could I blame them? It was a pretty nerdy opening line.) As I spoke, the way they looked at me changed. Their body language shifted from cross-armed and distant to relaxed with their body’s leaning in toward mine. They were shifting from doubt to empathy before my eyes. They were engaged. As I was teaching them, they had no choice but to learn. It was a powerful moment for me and later, I found out, for them too. I am going to tell you what I told them.
The human immune system has an extraordinary eloquence and precision. Nothing man-made can compete with its beauty and power. With that being said, this is a greatly simplified version of what happens during an allergic reaction but I think it is all you need to become an empowered educator. Okay, friends, are you ready?
There are two main allergic cells in your body, the mast cell and the basophil. These cells contain within them pockets (or granules, seen in red in image below) filled with chemicals that mediate allergic disease. Mast cells are found docked in tissues whereas basophils are floating around in the blood. Both of these types of cells have receptors on their surface. Some of these receptors have IgE (immunoglobulin type E) antibodies attached to them. Think of the IgE antibody as a hand that projects out from the cell (seen in dark blue, shaped like a “Y” in image below). Each of the hands will only grab onto specific food proteins. They have a favorite food, so to speak.
Those are the main cellular players. Now here’s what they do. An individual eats a food to which he or she is allergic. Let’s say it is a peanut but it could be virtually any food. The peanut enters the gastrointestinal (GI) tract, whether it is peanut residue that cannot even be seen or an actual piece of a peanut. At some point, the tiny allergenic peanut protein passes thru an insecure barrier in the wall of the GI tract. The peanut protein then finds its way, through a series of events, to the blood stream and tissues. Here is where the peanut protein finds the mast cells and basophils.
Now, there are those “Y”-shaped IgE antibodies (the hands) on these mast cells and basophils, remember? The hands on some of the cells of a peanut-allergic person are looking for peanut protein. When these hands make contact with the peanut protein, they grab onto it and in turn, the cell becomes “excited”.
The pockets of chemicals (granules) found within the cells quickly move to the edge of the cell and pour their chemical contents out into the bloodstream or tissues (degranulation). The chemicals spewing from these cells (seen in red in image below) include histamine and tryptase, among others. This process of degranulation can occur very rapidly and does not just occur in a few cells but instead in many cells all over the body. This process occurs even if there was only a miniscule amount of peanut protein that originally started the reaction, even if the blood test showed a low number for peanut, even if all of the past reactions were minor. If this process were not deadly, I would say that the efficiency and rapidity of the reaction borders on fantastic.
Histamine, tryptase and the other chemicals that are now swirling in the blood and the tissues start to wreak immediate havoc and the signs and symptoms of anaphylaxis are quickly evident. Anaphylaxis hits as sudden as a summer storm. The damage is frightening and widespread. Histamine causes many changes to occur in the body. Some of these effects are more considerable than others. Histamine causes smooth muscles to contract leading to abdominal pain, cramping, nausea, vomiting and diarrhea. It can lead to wheezing (like asthma) from airway constriction that can ultimately lead to respiratory distress, respiratory arrest and death. Histamine also causes vasodilatation. This is when blood vessels get bigger and have less ability to contract to get blood back to the heart. This can cause a decrease in blood pressure that can lead to dizziness, feeling faint, shock and death. Histamine also induces microvascular leakage. This means that both cells and fluid that are supposed to stay in the blood vessels are able to leak out of the blood vessels. This can lead to hives, itching, and swelling of the throat leading to suffocation. If enough fluid leaks out of the blood vessels, there can be accompanying decrease in blood pressure leading to shock and death. Histamine can also cause marked mucosal edema and mucus secretion. It can cause the airways to become swollen and filled with mucus making it difficult for oxygen to get from the air we breathe into the blood that circulates around our body.
Now we are in the midst of anaphylaxis, WE MUST STOP IT. YOU MUST USE INJECTABLE EPINEPHRINE. How does epinephrine work to stop an allergic reaction? You need to know this. You need to understand WHY you must carry this everywhere you go. You need to know WHY you must use this medication when your son or daughter, parent, grandchild, student, or friend is having a serious allergic reaction. I told you how fast these reactions occur (and many of you have seen the speed of a reaction first hand) so there is no time to waste. If someone is experiencing anaphylaxis, injectable epinephrine must be given immediately. Be a hero. Save a life. Don’t be afraid. Once you give the injectable epinephrine as instructed, here is what it does…
Epinephrine constricts blood vessels. This is important because it curbs that microvascular leaking that leads to decreased blood volume and plummeting blood pressure, potentially leading to shock and death. Epinephrine relaxes airways. So while histamine is trying to make the airways tight, epinephrine tries to relax them in order to allow air to pass more easily. Epinephrine helps to decrease swelling in the upper airway so that air is not obstructed from getting to the lungs. It decreases cramping of the GI tract. It helps to block the hives and itching that accompany an allergic reaction. Epinephrine can help to stop anaphylaxis from progressing to death if given early and appropriately. It is the only thing that can. Antihistamines can relieve some of the skin symptoms (hives, itch) but they do not have the ability to save a life from anaphylaxis.
To summarize: The food that one is allergic to enters the body. It finds its way to allergic cells (mast cells and basophils) that recognize only certain foods through their IgE antibodies. Once the allergic food protein binds to that IgE, the cell pours out chemicals (histamine and tryptase) that cause swelling, itching, decreased blood pressure, and can ultimately lead to death. Epinephrine counteracts these effects. It decreases swelling, increases your blood pressure, makes your heart pump better and helps to prevent a fatal reaction.
That is anaphylaxis in a nutshell, so to speak. This is why it can be deadly and this is why epinephrine can save a life. Please share this post with your friends, families, teachers, administrators, school nurses, physicians, and anyone else you can think of. I know it is a long post but it is so very important. If we do not push to educate others, I’m afraid that we are going to continue to lose our sweet and innocent food allergic children to anaphylaxis. We simply cannot stand for this and, if I know anything about families who have children with food allergies, I know we won’t stand for this. There is too much at stake.