Only 1 in 5 people with a penicillin allergy actually had penicillin allergy

In case you’re wondering how people get falsely labeled as having a penicillin allergy, I have an anecdote: My grandad with a “penicillin allergy” was recently treated with a high dose of penicillin for 4 days without any problem. The hospital didn’t have access to his medical records and also overlooked what we wrote on the admission forms, and went ahead with penicillin as the best treatment. I asked my grandad about this allergy. He said that 40 years ago he had an upset stomach after taking penicillin and the doctor told him he was allergic. He’s been repeating that information to doctors and pharmacists for 40 years.

I had a terrible reaction to penicillin during a bout of mononucleosis. I've read that it's not uncommon to have a negative reaction to it when you have mono, and that it doesn't indicate an allergy, so I'm not sure I actually have an allergy. I never had a problem with it prior to that. It was such a bad reaction that I don't want to take a chance, though. Every few years, I explain this to a doctor, and when I give them the details, they usually respond along the lines of "yeaaaaah, let's keep avoiding that." One of these days I'd like to get a controlled allergy test for it, but meanwhile, it gets listed as my only allergy to anything.

I've submitted this with the title "Only 1 in 5 people with a penicillin allergy actually had a penicillin allergy". The title in the journal is "Implementation of a pharmacist-led penicillin allergy de-labelling service in a public hospital | Journal of Antimicrobial Chemotherapy | Oxford Academic".

Huh. 98% of those 'de-labelled' went on to have no adverse reaction to penicillin.

So, what about the 2%? Small study - was that just one person? What was the reaction? Did they die? It's important to understand the cost of a 'false negative' here.

At the same time understanding that, NOT treating folks mis-labelled with an allergy has a cost as well.

Having a allergic reaction once - from a disrupted / suppressed immune system - and having an actual allergy are two different conditions.

When the majority of the masses falsely believe antibiotics are something you take for a flu or a cold, then educating them on fluctuations in immunity is probably too much to expect.

What's worse is that these false penicillin allergies have precluded the use of similar drugs such as cephalosporins, despite a very low cross reactivity, and worse drugs such as vancomycin were used as substitutes. Thankfully, increased attention will help to decrease overuse.

Never summarize as “allergic” to a medical professional; they need the details.

I indicate on medical forms that Vicodin gives me waking nightmare hallucinations, because it doesn’t kill me like an allergy, but they should be aware of what they’re in for if they do select it. (This straightforward disclosure has encouraged many years of good decisions by doctors who, I suspect, would rather not have my screams of terror interfering with their work :)

Nice. I've always had to fill in penicillin allergy, but have been skeptical. Now, more reasons to be skeptical.

The US and Western Europe are extremely neurotic. All it takes is the mention that an allergy is possible to have for 20% of people to start claiming that they have it.