Penicillin Allergy research

[SilverLining]

http://www.cbc.ca/news/health/penicllin-allergy-1.4262726

Many people who are labelled as allergic to penicillin can safely take the important antibiotic, say doctors and pharmacists who brought testing to the bedside of patients in hospital.

The penicillin family of antibiotics remains a workhorse for infections ranging from urinary tract infections to pneumonia. They're often considered the safe, first choice. Infectious disease specialists increasingly want to preserve penicillin in the fight against antibiotic resistance — the arm's race between microbes and drugs to fight them.

Yet one in 10 Canadians report an allergy to penicillin, which doctors know is an overestimate. Now, investigators at three hospitals in Toronto who followed a rigorous testing protocol say they were successfully able to give penicillin to the vast majority of more than 600 people who had the allergy on their medical chart. 

[SilverLining]

Palmay and Leis said there are few reasons for the overestimate:

Allergic reactions can wane or disappear over time.
Patients have an intolerance to penicillin rather than a true allergy that automatically restricts use of the drug.
Something else was going on to cause the original reaction, such as a viral infection, that was mistaken for an allergic reaction.

Two of my kids reacted both times they were given penicillin. One also definitely had a serious reaction to other mold. The second we think was reacting to other mold.

The youngest, his scratch test to mold was so severe the allergist refused to test for penicillin and if I had wanted it done, he said it would be against his judgement and must be done in hospital.

So....while this is great news, I don't think it necessarily is for my family.

[rebekahc]

The over reporting of PCN allergies is why my surgeon gave me an IV cephalosporin prior to surgery that resulted in anaphylaxis.  He told me, "If I had really thought you were allergic to penicillin, I wouldn't have given you the cephalosporin because 10% of people with penicillin allergy will also react to cephalosporins (and 90% of people with cephalosporin allergy are allergic to penicillin).  I guess you really are allergic to penicillin." 

I don't seem to react more than typical to molds, though.  Weird.  I knew PCN was derived from mold, but I have never been told the two allergies were related.  Maybe that's why I can't stand bleu and other moldy/stinky cheeses?

ETA:  Here's what I found with a quick search - haven't looked for any official sources...

Does Penicillium Mold Allergy Mean You Have a Penicillin Allergy?

In short, no. While the antibiotic penicillin was originally developed from Penicillium, people with mold allergy are not at an increased risk of developing an allergy to this class of antibiotics.

Modern-day penicillin antibiotics are produced synthetically and are not contaminated with mold particles.

[hezzier]

My father had a reaction to penicillin.  As kids, we were told never to have it...I've had it in a hospital setting (I think) and had no issue.  I don't know if my sister has ever had it.

[SilverLining]

The over reporting of PCN allergies is why my surgeon gave me an IV cephalosporin prior to surgery that resulted in anaphylaxis.  He told me, "If I had really thought you were allergic to penicillin, I wouldn't have given you the cephalosporin because 10% of people with penicillin allergy will also react to cephalosporins (and 90% of people with cephalosporin allergy are allergic to penicillin).  I guess you really are allergic to penicillin." 

I don't seem to react more than typical to molds, though.  Weird.  I knew PCN was derived from mold, but I have never been told the two allergies were related.  Maybe that's why I can't stand bleu and other moldy/stinky cheeses?

ETA:  Here's what I found with a quick search - haven't looked for any official sources...

Does Penicillium Mold Allergy Mean You Have a Penicillin Allergy?

In short, no. While the antibiotic penicillin was originally developed from Penicillium, people with mold allergy are not at an increased risk of developing an allergy to this class of antibiotics.

Modern-day penicillin antibiotics are produced synthetically and are not contaminated with mold particles.

That is interesting. But I'm sticking with what the allergist said for DS. (Not thinking you are advising otherwise. More info is always best, and if he were to see an allergist again I would want to discuss this with him/her.)

My father had a reaction to penicillin.  As kids, we were told never to have it...I've had it in a hospital setting (I think) and had no issue.  I don't know if my sister has ever had it.

We have always been told penicillin allergy is not hereditary. But, FIL had anaphylactic reactions to it. Both my kids that were given it had reactions to it. BIL never thought a thing about it. Went in to have wisdom teeth removed. Woke up 3 days later with a really relieved but po'd doctor. "Why didn't you TELL ME you were allergic to penicillin". Yup...anaphylactic reaction for him too.

[hezzier]

We would have been told this in the 70's so maybe that information wasn't available at the time...who knows.  No one ever saw an allergist in our family until DS had a reaction in 2008-ish.

[SilverLining]

We would have been told this in the 70's so maybe that information wasn't available at the time...who knows.  No one ever saw an allergist in our family until DS had a reaction in 2008-ish.

Well, they kept telling us it doesn't run in families....but everyone in dh' family that got it had reactions. Maybe it's coincidence...but seems more than that to me.

Most in the family just refused it.