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Antibiotic Stewardship: Can PCN Skin Testing Help

Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.

Listen in as Allison Clare Ramsey, MD discusses this stewardship and how PCN skin testing might help in this study.

Antibiotic Stewardship: Can PCN Skin Testing Help
Featured Speaker:
Allison Clare Ramsey, MD
Allison Clare Ramsey, MD is a Rochester General Medical Group Physician and specializes in internal medicine, allergy and immunology.

Learn more about Allison Clare Ramsey, MD
Transcription:
Antibiotic Stewardship: Can PCN Skin Testing Help

Bill Klaproth (Host): What is antibiotic stewardship and how does that apply to penicillin skin testing, and what do you need to know about that? With us is Dr. Allison Ramsey from Rochester Regional Health. Dr. Ramsey, thanks for being here. First off, can you give us a quick overview of antibiotic stewardship?

Dr. Allison Ramsey (Guest): I'd be happy to. Antibiotics stewardship is a hot topic in medicine these days and what it really means is reserving or keeping more powerful antibiotic in reserve for more resistant infections and using the right antibiotics for the right infection. The reason that applies to penicillin allergy and even other antibiotics allergy is patients who have a number of antibiotic allergies listed in their medical record often need to graduate to the more powerful antibiotic to treat an infection that could potentially be treated by a different and more effective antibiotic that they're avoiding because they're allergic.

Bill Klaproth: So, you want to start with a, I want to say, smaller dose, but you want to start with the one that's not as powerful before going full bore in, is that right?

Dr. Ramsey: Yes, without bringing everybody through a lesson in microbiology and antibiotics, there are multiple different antibiotic classes and there are many different types of bacteria. We know certain antibiotics are effective for certain types of bacteria. They kind of match up like puzzle pieces. With antibiotic allergies, sometimes you don't have a puzzle piece that fits the best available to you because you're allergic to it.

Bill Klaproth: So, trying to match the correct antibiotic to the infection that the patient has is the first step, then?

Dr. Ramsey: Correct.

Bill Klaproth: If the wrong antibiotic is given, like you said, maybe the full dosage when the smaller one could have done the job. Is that where the whole antibiotic resistance comes in?

Dr. Ramsey: Right. I wouldn't call it the wrong antibiotic necessarily. Many infections have multiple different antibiotics that could treat the infection but you want to use the one that's just right. When you aren't able to because of an allergy or patient is not able to take the antibiotic, using a more powerful antibiotic from maybe a different antibiotic class can, sort of over time, train bacteria to come up with ways of becoming resistant. And so, actually it's the bacteria that become resistant to the antibiotic, not the patient.

Bill Klaproth: When it comes to penicillin skin testing, explain that to us. if someone has an allergic reaction to penicillin you need to know that. So, tell us about penicillin skin testing?

Dr. Ramsey: Right. Penicillin allergy, just to give you a little bit of background, I'm sure many of the listeners are thinking, "I have a penicillin allergy." It's common. ten percent of the population have a self-reported penicillin allergy. Through medical studies, we know that about 90 percent of the people walking around with a penicillin allergy aren't really allergic to penicillin.

The reason that's important is that penicillin antibiotics are still effective. They have been around for a long time but they're still effective for a lot of infections that people routinely encounter: ear infections in children, sinus infections in adults, pneumonia in adults. If 10 percent of our population is walking around with this penicillin allergy, then they're the ones avoiding the antibiotic probably unnecessarily, like I said, in 90 percent of the cases.

We as allergist actually have a pretty under-utilized test, which is the penicillin skin test, and what that is, it's not different than people that have been tested to environmental allergies or food allergies, at least for the first step. The first step of this skin testing involves making a little poke in someone's skin with penicillin and then sort of a component of penicillin, and then we wait 15 minutes. If they're allergic to penicillin, they'll get an itchy bump. People that have had environmental testing or food allergy testing are familiar with that.

Then, the next step of the penicillin test is an injection under the skin, and, again, we wait fifteen minutes and look to see if there's an itchy bump that develops. Most of the time, there isn't. And so, when someone has negative penicillin skin testing we say, "Okay! Your chance of having and anaphylaxis type reaction which includes trouble in breathing or hives or itching, is really bad in anyone off the street, and so if we have negative penicillin skin testing and someone who has it, a remote or a long time ago history of possibly reacting to penicillin, that's really reassuring that we can try it again in their case.

Bill Klaproth: You talked about a negative reaction. What is the worst case scenario for someone who has penicillin allergy if they're given penicillin?

Dr. Ramsey: You mean in the absence of skin testing? You took someone off the street and gave them penicillin, what would happen?

Bill Klaproth: Yes, and how do we know that? Do we all get tested for penicillin allergies as we're growing up?

Dr. Ramsey: No.

Bill Klaproth: Me, as a normal person, how would I know if I have a penicillin allergy? I'm kind of curious? And, if I did know that I had one and I was given penicillin, you kind of alluded to what would happen but what's the worst case scenario, then, if I'm given penicillin?

Dr. Ramsey: The most important part, to take a few steps back as allergist and when we're evaluating if someone has the penicillin allergy or another drug allergy, is by getting the history of someone's reaction. If you've never had the medication, you can't be allergic to it. But, people usually have something that they have experienced either in adulthood or in childhood.

Oftentimes, they've been told by their parents. The type of reaction that our skin testing for penicillin addresses is what we call an "immediate" type reaction and the symptoms that can go along with that would be hives, itching, redness of the skin, swelling, trouble breathing, cough, or changes in blood pressure. When you have those symptoms involving two or more systems in your body that's anaphylaxis. I think people recognize that word as a severe allergic reaction.

That's kind of a worst case scenario for a penicillin reaction. And, that's what we can test for. So, if someone has a reaction that sounds consistent with those symptoms but it occurred in childhood or it occurred fifteen years ago, it's worth revisiting because you're immune system can forget.

Bill Klaproth: Can forget or does it change over time?

Dr. Ramsey: Right. It can resolve over time. With penicillin allergy, a lot of what happens is in childhood, people are labeled with a penicillin allergy because they're on a penicillin-based antibiotic for an ear infection or a sinus infection and they develop a rash that probably is due to the infection itself and not due to be antibiotic, but there is no way of knowing timing wise.

So, a lot of people march into adulthood with an allergy that maybe was never even a true allergy to begin with. I should say that there are other parts of your immune system that can cause allergic reactions that we don't have testing for. So, the most important part of my evaluation as an allergist when I'm speaking with a patient with a penicillin allergy or another drug allergy is really just getting at the heart of their history, what specific symptoms they had, and then we can decide if they're a candidate for penicillin skin testing.

Or, sometimes my advice is to continue to avoid the specific medication, or sometimes my advice is to do what we call a challenge, where we actually give patients doses of the medication because we think it's unlikely they're allergic to it.

Bill Klaproth: Those are good ways to really understand whether or not a person is allergic to penicillin. You have mentioned ear infections, sinus infections, pneumonia. I would imagine most of our listeners that have had kids with ear infections, Amoxicillin is a penicillin-based antibiotic, right?

Dr. Ramsey: Correct. That's exactly what I'm saying. A lot of times kids are labeled with a penicillin allergy because there's no way to know. If you get a rash while you're on Amoxicillin, maybe it's the virus, or the infection, or maybe it's the antibiotics.

In most cases, it's not the antibiotics but the antibiotic ends up getting under the allergy label to be safe. So, it's worth revisiting that as children get older, or if it's happened in childhood and you're now an adult because Amoxicillin is a very effective medication for ear infections, sinus infections, and a lot of times it is unnecessarily avoided.

Bill Klaproth: Dr. Ramsey, if someone is allergic to penicillin what is used in its place to treat infections?

Dr. Ramsey: It depends on the infection, honestly. Penicillin have a cousin antibiotic called
"Cephalosporin". Those generally can be used if someone is truly penicillin allergic, and those are often used in the pediatric population for ear infections, or sinus infection. For pneumonia, there's a whole other class of antibiotics called the "fluoroquinolones" that may be used.

So, there are other options. People tend to get in a little bit of trouble when they have a crude...an antibiotic from multiple different classes that's when it becomes trickier to find something to treat them with. If it's not penicillin, if someone has multiple other antibiotic allergies, it's still worth talking about that and getting those addressed, and to revisit them to see if someone truly needs to continue to avoid them.

Bill Klaproth: Absolutely. That makes total sense. The good news is, if you do have penicillin allergy, there are other drugs that can treat your infection, so that's the good news with that.

Dr. Ramsey: Correct.

Bill Klaproth: Sounds great. Well, thank you so much for your time today, Dr. Ramsey. Why should someone choose Rochester Regional for their health care needs?

Dr. Ramsey: Speaking for our allergy practice specifically, we have doctors who work very hard to keep up with the current literature and medical studies to treat our patients and are the most up to date with the most treatments. I know that's true in all areas of the hospital system. Everybody in our system cares about the patient, from the people checking you in to the nurses helping with your care, to the doctor directing your care.

Bill Klaproth: Well, Dr. Allison Ramsey, thank you so much for your time today and talking to us about penicillin skin testing. You're listening to ROC Your Health Radio with Rochester Regional Health. For more information, you can go to www.rochesterregional.com. That's www.rochesterregional.com. I'm Bill Klaproth. Thanks for listening.