Are you really allergic to penicillin?

When my son was about 10 years old he got an infected blister on his foot. I took him to the pediatrician to have the abscess drained, and then he was given a prescription for Augmentin, a fancy and expensive form of amoxicillin.

(If I knew then what I know now, of course, I would have 1) questioned whether an antibiotic was really necessary, and 2) wasn’t there a cheaper alternative to a brand name drug?)

Within 24 hours of taking the Augmentin, my son developed a terrible case of hives starting on his infected foot and eventually running up both legs and onto his torso. I had no doubt he was having an allergic reaction, most likely to the Augmentin.

I called the pediatrician’s office and the nurse seemed baffled when I told her my son appeared to be allergic to the Augmentin. I think she doubted my ability to diagnose a simple case of hives. Whatever. I said I was discontinuing the antibiotic and if the doctor wanted my son to take something else, they should call me.

The nurse called back a while later and said it was OK to go without any more antibiotic (confirming that my son didn’t really need it to begin with!).

Amoxicillin is a form of penicillin. My son had used amoxicillin and penicillin several times since birth and never showed signs of a drug allergy, so I was surprised by his reaction to the Augmentin. Still, allergies can develop later rather than sooner, and from then on, I always put “allergic to penicillin” on all his health forms for sports and school.

But I never took the time to actually have him tested for a penicillin allergy. There are so many antibiotic choices, it just didn’t seem worth the time and money.

But I just read an article that has me thinking again.

Researchers found that most people who are told that they are allergic to penicillin were mistakenly diagnosed as such based on initial reactions instead of a confirmatory test.

This mistaken perception led many to opt for more dangerous antibiotics and other treatments for their infections. Researchers pointed out that the patients who were thought to be penicillin-allergic had to take other antibiotics that put them at greater risk for acquiring complications such as colitis and the development of more antibiotic-resistant strains.

Penicillin is cheap, effective and relatively risk free. Other newer antibiotics are not.

I also read a post by a pharmacist on the blog Science-Based Medicine that supports my new plan to encourage my son to be officially tested for a penicillin allergy.

…allergies to penicillin are widely reported. Statistically, one in ten of you reading this post will respond that you’re allergic to penicillin. Yet the incidence of anaphylaxis to penicillin is estimated to be only 1 to 5 per 10,000.

So if you think you’re allergic to penicillin, but are not certain of the type of allergy you have, testing is something worth thinking about. Without it, you’re setting yourself up for a lifetime of risk and consequences of the avoidance of penicillin. Data show that patients considered penicillin-allergic will typically receive more broad-spectrum antibiotics, which may have more side effects, be more expensive, and in some situations, less effective.

People over report penicillin allergies because they mistake side effects or adverse effects such as upset stomach or diarrhea for an allergy. Hives is a pretty clear indicator of an allergic reaction, but perhaps my son was exposed to something else at the same time as the Augmentin? It’s possible.

The point is I don’t know for sure, and it now seems ill-advised for my son to continue to label himself as allergic to penicillin.

From the Mayo Clinic: Testing and diagnosis of penicillin allergy

Do you think you or one of your kids is allergic to penicillin? Why? Have you been tested for the allergy to find out for sure? If not, consider doing so. You don’t want to limit yourself to a smaller choice of antibiotics, especially when they might cost more and come with more side effects.


Frugal Nurse



Are you really allergic to penicillin? — 2 Comments

  1. Very interesting post. I had an allergic reaction to amoxicillin years ago but never to penicillin. Penicillin always worked well and quickly and I’ve missed it. One doc said it’s possible that penicillin would be ok but was averse to prescribing it. I might look into the allergy testing if it’s covered.

    • It should be covered, although the cost would be like most specialist procedures and go towards your deductible. Unless the test is exorbitantly expensive, it would be worth it, I believe, to have the information. I have not researched the cost yet, and wouldn’t even begin to guess. If you find out, please let me know! Cheers, FN