Allergy vs. Intolerance

Medical semantics say that food allergies and food intolerances are not the same. So let’s define some things according to the way that doctors use those words.

“Allergies” are mediated through the IgE part of the immune system. I have a friend who has a life threatening reaction to shellfish. She has almost died on any number of occasions. Not all food allergies are this severe. Some cause hives, some constipation, diarrhea or bloating. Some headaches. Some eczema and skin rashes.

“Food intolerances” are mediated through the IgG part of the immune system. Intolerances will never cause a life threatening reaction, but they will cause constipation, bloating, skin rashs, eczema, headaches, diarrhea, etc.

[Here’s a sticky problem: sometimes doctors use intolerances to indicate non-IgG related problems. For instance, people who lack the enzyme to digest the sugar in milk are called “lactose intolerant.” This type of food intolerance is a completely different animal than what I’m talking about here, and this is part of why people don’t take my kind of food intolerances seriously. In my blog and this article, I am talking only about IgG mediated immunological reactions to food. This is another example of why I object to the use of the word “intolerance” – it’s not consistent in what it refers to, even when medical professionals use it.]

If you are seeing some similiarities between the less severe IgE reactions and the IgG reactions, good, because there is a lot of similarity. The number of people that have the lift threatening type of IgE reactions is very small, most of my reading indicates it’s about 1-2% of the population will have that kind of reaction to food.

So both “allergies” and “intolerances” involve the immune system seeing food as a foreign invade and acting upon it. Anyone who tries to tell you that “intolerances” are not an immune response is wrong. So why do people make such a big deal about the semantics?

The word allergy is from the Greek allos, other + Greek ergon, action. The definition according to Stedman’s Medical Dictionary is “An abnormally high acquired sensitivity to certain substances, such as drugs, pollens, or microorganisms, that may include such symptoms as sneezing, itching, and skin rashes.” Notice that there is no indication in this definition about whether the sensitivity is mediated by the IgE or the IgG portion of the immune system. It’s just an acquired sensitivity. Period. My theory is that doctors invented the semantics game we are now playing, and there is some serious fallout from that game. Keep reading.

I have food intolerances, and they have miserable side effects – eczema that takes months to clear up (if it clears up at all), weeping skin lesions, migraine headaches that cause vomiting for days on end and don’t respond to medications, etc. Those foods that I am intolerant of are just as poisonous to my body as if I were “allergic” to them. According to Stedman’s I AM allergic to them after all. I’m demonstrating an acquired hypersensitivity to them, am I not?

By the way, most food allergy responses will go away the same day, while some of my food intolerance reactions create eczemas which don’t go away. Ever. Which is worse/more severe? People playing the semantics game about the word “allergy” need to get a clue. Both intolerances and allergies are a form of living hell if you eat the wrong thing.

Here is why I write this post: when you use the word “intolerance” with people who don’t understand the immunological basis of intolerances or the long-term consequences that eating that food will have, they don’t take you seriously and they’ll lie to you about what’s in the food. Or they just won’t check that carefully. Or they won’t check at all. (Happened to me just last week.) Food servers don’t really care if you are intolerant. They won’t be around for the months of fall out caused by their meal. Same thing with friends or well-meaning co-workers. It’s not going to be their problem.

But tell a restaurant or a friend that you are allergic and they will make sure that you are not getting that food that is poison to you. That’s self-interest for them – they picture you having an anaphylactic reaction and dying right there in their restaurant. Suddenly liability is involved and, miraculously, they care!

If people truly understood the ramifications of intolerances and were as compassionate/considerate about them as they are about allergies, I’d use proper terminology. If, however, the only way I can get respect for my body’s needs is to say “allergies,” then by God that’s what I’ll say, even though I know I’m breaking the rules of the semantics game.

Here’s an anecdote for you. I have an IgG-mediated immunologic reaction to eggs as a foreign substance. The day after I was diagnosed with this, I had the flu shot. The nurse giving the shot at CIGNA asked me if I had any allergies. I said no (right? because I have intolerances, not allergies). Within 15 minutes of the shot, my arm had swelled to 3 times its normal size, it was red and hot to the touch. I went to the nurse at work and she said, “my, you must be allergic to eggs.” She started to get me an ice pack and some benadryl. I told her, no, but I do have an intolerance to them. She said, “oh, well, no big deal then. If you have a chance, put some ice on that.” And she stopped paying any attention to me. Didn’t give me an ice pack, didn’t give me a benadry. It took 4 days for my arm to go back to a normal size, color and temperature-even with ice pack and benadryl, which I had to provide for myself. I was in agony that entire time. Couldn’t lift my arm. Could barely type (which is a major part of my job) because I couldn’t hold my arm up for longer than a few seconds. Couldn’t sleep at night. No one else at work had any kind of reaction to the shot. Just me. Ironically, had I told the nurse giving out the shots that I was allergic to eggs, she wouldn’t have given me one. Or if I had told the nurse at work that I was allergic to eggs, she would have given me an ice pack and some benadryl. But there is no sympathy or consideration for intolerances. People, even medical personnel (maybe especially medical personnel since they are the semantics game players after all) don’t care about intolerances because they don’t see them as serious.

Another anecdote: again, a few days after the diagnosis, before things had really sunk in for me. I was at Carl’s Jr. with some friends and I ordered a lettuce wrap burger. It completely slipped my mind that they put mayo on the burgers as standard practice. In fact, I was halfway through the burger before it struck me that I was eating mayo and that mayo is made with eggs. And then, because I was new at all this, I thought to myself, “Well, a TBSP of mayo is no big deal. I’m not going to worry about it.” Well, within 15 minutes, I felt like I had a hot rock in my belly. Within an hour, I was throwing up. For the next 3 days I was down with a migraine. Because of a TBSP of mayo and a food “intolerance.” My own fault because I wasn’t taking my food issues seriously.

So here’s the deal: I use the word allergy for both IgE and IgG mediated immunological responses to food. If you need clarification, I’ll tell you that all my food allergies that I write about here are IgG mediated immunological responses to food. And they are serious disorders that severely affect the quality of my life. I’m not playing the semantics game anymore. I’m going with allergy and that is perfect congruent with the Stedman’s definition.