There's a full page discussion of anaphylaxis in plain English at the US National Institutes of Health website, which is well worth reading. Here at this blog the goal is simpler: we'll assume you have a friend or an adult family member who gets anaphylaxis to some sort of food. What do you need to know? What should you do?
The most important thing to know is that anaphylaxis is the only type of allergic reaction that can kill. A 2001 study found that approximately 100 Americans per year die from anaphylaxis to food allergens. That's serious stuff. The good news is that the death rate from anaphylaxis is declining, mostly because people are getting better at managing it.
So what the hell is this?
You may have been asked at a doctor's office whether you're allergic to antibiotics. Or you've heard about people who have to carry a bee sting kit. Or you've been asked whether you're allergic to latex or iodine. All of those things are known causes of anaphylaxis. Anaphylaxis caused by food isn't really different: the problem with all anaphylaxis is a serious malfunction in the immune system.
When the immune system works correctly it recognizes viruses and bacteria by producing antibodies to surface proteins. The antibodies summon mast cells--a type of white blood cell in the bloodstream--and the mast cells mount the immune response. When an allergy develops the immune system produces antibodies that bind to surface proteins in a completely harmless substance--hayfever is a common allergy to the ragweed pollen--the immune system response is why a lot of allergies have similar symptoms to the common cold. Allergies are irritating and some can ruin a sufferer's day, but the only type of allergy that becomes a true medical emergency is anaphylaxis.
The biochemistry of anaphylaxis is a perfect storm. There are several ways to die from anaphylaxis, none of them pretty. Some anaphylactic reactions cause swelling of the breathing passages, which can close off the airway completely. It's like getting strangled by one's own body. Another way to die is severe vomiting coupled with partial breathing obstruction; basically that's choking on one's own vomit. Just in case that isn't grisly enough, other people who suffer anaphylaxis get severe full body hives. The itching from that defies description, but the real danger comes from the resulting drop in blood pressure as fluids rush from the bloodstream to the tissue near the skin. That can cause death from heart failure even in young adults who are otherwise in perfect health.
That's the worst case scenario. Most people who get anaphylaxis won't die from it but it's important to keep in mind what could happen in order to protect against it.
This is where you come in as the friend or family member of someone who has an anaphylactic food allergy. It should be obvious by now that they aren't just looking for excuses to get attention and they aren't trying to control people: this is a real medical problem. A person who gets anaphylaxis to food doesn't have any more power over their predicament than someone who gets anaphylaxis to penicillin: the problem happens on a biochemical level and they're stuck with it. They aren't able to negotiate. If someone else in your family couldn't eat grapefruit because they're taking heart medication and grapefruit could cause fatal drug interactions you wouldn't argue with that. You can't argue with anaphylaxis either. It isn't psychosomatic.
What's the scope of this problem?
The top 8 food allergens account for 90% of anaphylactic reactions. These are:
- Milk
- Eggs
- Fish
- Shellfish
- Tree nuts
- Peanuts
- Wheat
- Soybeans
Ask questions from the person you know who has the allergy: what do they react to? What precautions do they need?
A person can be allergic to one or two of the items on that list without being allergic to any of the others. Also bear in mind: 10% of anaphylactic food allergies aren't on that list. There are dozens of other foods that can also cause anaphylaxis. Your humble blog author is among that other 10%; I've been hospitalized multiple times for reactions to stone fruit. That's a botanical category which includes apples, grapes, peaches, pears, nectarines, cherries, plums, blackberries, and raspberries. What I have is a severe case of Oral Allergy Syndrome. OAS is usually mild, but in a few instances it manifests as full anaphylaxis--which is basically as dangerous as an allergy to peanuts or to penicillin. There are other types of rare food anaphylaxis; the important thing to know is that even though the FDA doesn't have food labeling requirements for those less common types our needs are every bit as real and serious as nut allergies. You could say that there's a problem the food label laws ignore us--and I would agree with that--but for now these are the waters we swim in.
