One-half to two-thirds of what patients report to me as their allergies really are not allergies. They tell me things like: I’m allergic to codiene, it makes me throw up. Allergic to erythromycin, it gives me diarrhea, allergic to aspirin, it upsets my stomach. Etc. Etc. These are not allergies, these are side-effects. They can be mild, and treatable, or may be life-threatening, but they are side-effects, not allergies. Even many rashes, particularly to amoxicillin, are not true allergic reactions, but side-effects.
A true allergic reaction is one where a substance triggers the body’s immune cells to release histamine, causing an anaphylactic-type reaction which may include: skin eruptions or hives, often with tremendous itch, bronchospasm with wheezing or shortness of breath, and vasodilation with flushing and possibly dropping blood pressure. Mild reactions often stop themselves, others improve with a little diphenhydramine (Benadryl). Severe reactions can kill. It’s very unusual to have a true allergy to benadryl, as it is an anti-histamine, and counteracts allergies. Usually the allergy is to one of the inert ingredients in it, like a food dye.
My job as a doc is to tease out what people are really truly allergic to, by history if I can. Many times I can identify a side-effect, and plan to use the medicine, such as an erythromycin-type drug, cautiously. If I have serious doubts about needing to use a necessary drug, I can refer to my friend the Allergist for advice on allergy testing.
As antibiotic resistance grows worse, the worry that we may run out of drugs to use grows too, but I’ve not heard of any situations where health was jeopardized because allergies did not permit a drug to be given. pre-loading a patient with steroids, which reduce allergic reactions, and using hypo-allergenic inert ingredients, is generally effective.
WARNING; AMUSING BUT POINTLESS ANECDOTE FOLLOWS. (amusing to me, anyway.) It’s the story of shrimp man, who knew he was allergic to shrimp, but liked it a lot anyway. One day he had shrimp for lunch, and didn’t feel too good, so he decided to drive to my office. He staggered into the lobby, and sat in the nearest chair, without telling anyone he was there. Fortunately my Physician Assistant saw him, noticed he wasn’t looking too good, got help dragging him into the treatment room, and got me.
I walked in and saw a man who looked like the pillsbury doughboy. He had hives all over, including his eyelids! He was wheezing to beat the band, his oxygen level was low at 85% and his heart was racing, so I gave him a shot of epinephrine under the skin, and got my nurse to work starting an IV on his swollen arm, while we added oxygen, and I drew up more epinephrine, just in case.
Suddenly, Shrimp man starts calling out “I’m going, Doc. I’m going! I can’t see you anymore!” He’s sweating so heavily it’s running off his face in rivers, his heart rate is up to 150, and his blood pressure is 70 systolic. Suddenly his eyes roll back, and he collapses on the table. No blood pressure, no pulse. A pulseless nonbreather, technically he is now dead.
Fortunately, my nurse had just started the IV, so I push 1 mg of epinephrine straight into him, and sit back to wait, and see if we need to start CPR. Just as I’m about to thump his chest, he sits up, and starts hollering that his heart is going to explode. On the heart monitor, he’s in ventricular tachycardia, a potentially fatal arrhythmia. But he’s talking now, so that’s an improvement over being technically dead a few seconds ago.
Eventually he calms down, and stabilizes, and the paramedics get him the hell out of my office. I have time to see one more patient before my shift is over. I go into a room, where a young woman is crying hysterically. Her complaint? She found a bug in her food. She’s afraid she might have eaten a bug. I look at the bug. It’s a potato, or pill bug. I reassure her that it’s not poisonous, that in parts of the world bugs are a major part of the local diet. I tell her “the bug is actually related to shrimp. Are you allergic to shrimp?”
END OF POINTLESS ANECDOTE. SAFE TO READ AGAIN.
Qadgop