90% of people who think they have a penicillin allergy may not be allergic, experts say

GPs might be the key to preventing antimicrobial resistance by increasing access to penicillin.

Professor Michaela Lucas is a practicing clinical immunologist and allergist at the University of Western Australia working in paediatric medicine. She leads drug and allergy research at the National Allergy Council (NAC).

“Ninety percent (90%) of people [thought to have a penicillin allergy] can actually tolerate penicillin; they aren’t allergic. There is complete over-reporting of penicillin allergies,” says Prof. Lucas.

At the same time, reporting a penicillin allergy in hospital can lead to worse outcomes.

“10% of the Australian population will report a penicillin allergy, which translates to about 2.8 million people. So, it's a common problem.”

That number reaches 25% when it comes to older Australians. 

The World Health Organization (WHO) and The US Centre for Disease Control (CDC) predict that without increased antimicrobial stewardship, we will reach pre-penicillin conditions by 2050.

“Not only will [antimicrobial resistance] become a major economic burden on our hospitals, but people will die, as we move towards a pre-antibiotic era.”

The National Allergy Council (NAC), in partnership with Allergy & Anaphylaxis Australia (A&AA) and the Australasian Society of Clinical Immunology and Allergy (ASCIA), have launched a national public health campaign to promote safe assessment of penicillin allergy.

The NAC has developed new, peer-reviewed guidelines for GPs, specialists, and people living with allergies about how to manage penicillin allergy.

“Our task is to change how we manage drug allergy in Australia.”

The power of penicillin

Penicillin, discovered in the 1940s (and developed by Australian medical scientists Mary and Walter Florey), is still one of the most effective antibiotics we have. 

Prof. Lucas points out that there are not many new antibiotics coming to market. 

“Because of that, we need to preserve the whole repertoire. If we take penicillins out, we’re losing 10 to 15 really high-quality antibiotics.”

“And studies show people are getting these more serious infections if penicillins are avoided. They're staying in hospital longer. There are more readmissions. More infections in their joints.”

“That’s incredibly scary. The biggest advance, probably in human medicine, has been antibiotics and the reduction of infections that we now can treat. But if we don't pay attention there is going to be an epidemic of people dying of antimicrobial resistant infections in hospitals.”

“And it’s unnecessary.”

The aim is to increase actual re-assessment of penicillin allergies in a safe and effective way.

“There are multiple large international studies showing that [the over-reporting of penicillin allergy] is associated with worse outcomes in hospitals.”

“Penicillin itself, which you can take for a strep throat, is quite a narrow spectrum. It’s very specific for the antibiotic that you're wanting to treat.”

“Whereas other antibiotics can be very broad spectrum. They don't just kill the bacterium that's causing the infection; they also kill a lot of your gut microbiome and the good bacteria. If you take them for an extended course, some of these bacteria may not recover.”

“And it leaves gaps for bacteria that can grow in these niches that then may be resistant.”

Prof. Lucas says that overreporting also creates the opposite problem.

“Because clinicians already know that in the majority of cases the penicillin allergy label is incorrect, it's a bit like ‘The Boy who Cried Wolf.’”

“People in our hospitals have died because they were given antibiotics that they reported to be allergic to, because people didn't pay enough attention.”

“What we're saying is: know your allergy status.”

Allergy resources and training for GPs

Prof. Lucas says that GPs are the most important piece of the campaign. 

“There are about 330 allergy specialists in this country. But we've got 30,000 GPs. We have to work with GPs and enable them to do allergy assessments in their clinic.”

“We’ve developed an algorithm that a GP can go to. We’ve divided it depending on what the risk is.”

The Council recently gave a webinar for health care professionals.

“The resources are available via the Australian Society of Clinical Immunology, where you will find the webinar, and the updated guidelines with algorithms for GPs to follow.”

“You will find other resources in the context of drug allergy; there is e-training developed for GPs and specialists.”

“GPs can register and enter questions, for any type of allergy or clinical immunology, and within 48 hours somebody will answer the question.”

“We are also working on MBS item numbers for penicillin assessment challenges in the community and specialist setting. The National Allergy Council and ASCI have been lobbying to have more sustainable funding models for this type of assessment.”

“For example, if somebody says, ‘I had nausea and a metallic taste when I took the penicillin,’ the GP can tell them, ‘This is not an allergy. This is a side effect.’”

“We suggest that their GP gives them an antibiotic under observation for an hour, and it's all done.”

“There is a risk stratification for adults that is associated with a peer-reviewed paper based on the current evidence. The children's algorithm is also on the web page.”

“It's the first guideline worldwide developed on the latest evidence, which uses an Agree II tool and a DELFI panel, which is the best way of getting consensus across experts.”

“We also developed a campaign for patients and carers, so there is a lot of information that also explains [this all] to consumers.”

Australia leading the way 

Prof. Lucas notes that Australia is completely under-resourced for allergy immunology specialists.

“We have a tsunami of allergic autoimmune diseases coming our way, and there are not enough specialists.”

“Australia is leading the way in regard to [allergy]. For example, the European Academy of Allergy is now working with us to learn from our campaign and was at the Penicillin Awareness launch.”

“We need to understand that it's not a safer option to retain your penicillin allergy. It may well be the worst option [if the allergy is false]. It doesn't keep you safe. It might be a disadvantage.”

“We think at about 30 to 50% of the population will fall into this minimal risk and low risk category. And we can make a big difference and reduce the overall 10% rate of penicillin allergy labels in our society to probably closer to 5%, or less.”