A true allergic reaction is one of the most terrifying events in medicine. A child or adult who is highly allergic to bee stings or peanuts, for instance, can die within minutes without a life-saving epinephrine injection.
But one of the most commonly reported allergies — to penicillin — often isn’t a true allergy at all. The urgent question that faces physicians every day in emergency rooms and operating rooms is this: How can we know whether or not the patient is truly allergic to penicillin, and what should we give when antibiotic treatment is indicated?
It’s time for us to stop making these decisions out of fear, and look squarely at the evidence. Withholding the right antibiotic may be exactly the wrong thing to do for our patients. Here’s why.
Can’t we just prescribe a different antibiotic?
When we hear that patients are “PCN-allergic”, we’ve been trained from our first days as medical students to avoid every drug in the penicillin family. We’re also taught to avoid antibiotics called “cephalosporins”, which include common medications like Keflex. This is because penicillin and cephalosporin molecules have some structural features in common, raising the odds that a patient allergic to one may also be allergic to the other.
What does it matter? Can’t physicians just prescribe a different antibiotic?