GPs should challenge patients with penicillin allergies, but a lack of subsidies, fear of litigation and insufficient education is standing in the way.
GPs can safely challenge patients with low-risk penicillin allergies, potentially de-labelling them, but such challenges just aren’t happening, Australian research suggests.
Most patients assessed as low risk and challenged in primary care could have their allergy label removed, Dr Kyra Chua, infectious diseases physician at Austin Health in Victoria, said at the Australasian Society of Clinical Immunology and Allergy (ASCIA) conference in Sydney this month.
Dr Chua presented results of a recent small study of 51 patients who were listed in their medical records as allergic to penicillin and assessed as low allergy risk.
Patients were deemed low risk, using the Antibiotic Allergy Assessment Tool, if they had been labelled allergic following either a localised reaction, or a rash or unknown reaction before the age of 10 years.
None of these low-risk patients developed an immune-mediated reaction after being given a single dose of 250mg oral penicillin, resulting in all having their “penicillin allergy” label removed.
In the subsequent three-month follow up, one out of the five patients prescribed penicillin developed a rash and had their label reinstated, despite not needing treatment for the rash.
“We found that penicillin allergy assessment and direct oral penicillin challenge was feasible in the GP setting,” said Dr Chua.
“All four GPs in the study stated that they were likely or highly likely to continue to provide penicillin allergy testing after the study ended, but they were more likely to provide this on an ad hoc basis in a patient who required penicillin treatment rather than in a dedicated penicillin allergy clinic.”
Dr Chua suggested that “patients who fell into the high-risk [penicillin allergy] category could be referred to a specialist outpatient clinic for further testing”.
Currently in Australia, most drug allergy testing is performed in specialist outpatient clinics or in hospitals.
Although 10% of people report that they are allergic to penicillin, evidence shows that the true allergy prevalence is only 1%.
This over-reporting is a major public health concern, contributing to antimicrobial resistance, inappropriate prescribing and even mortality.
While ASCIA guidelines currently support GPs removing antibiotic allergies from medical records for low-risk patients who don’t react to oral penicillin ingestion, there remains limited published data to back this up.
“Whilst this study has too small numbers to unequivocally state that GPs performing penicillin allergy de-labelling is safe, there were no severe reactions requiring treatment and no immune-mediated reactions,” said Dr Chua.
“I think that GPs should be supported to de-label patients, provided that they can be provided adequate training and ongoing support.”
Dr Chua said that although feasible, major barriers remained for implementation into primary care including no dedicated Medicare billing code, limited GP appetite for litigation risk in the case of adverse reaction and a knowledge gap among GPs because penicillin allergy assessment and oral challenge were not in the RACGP syllabus.
The Journal of Allergy and Clinical Immunology 2023, online 10 August
