‘De-label’ hope for people who mistakenly believe they have penicillin allergy

People who mistakenly think they are allergic to penicillin could be “de-labelled” – without undergoing expensive allergy tests – by being safely offered a dose of the antibiotic to check for any adverse reactions, research suggests.

A small trial involving 126 people in three UK hospitals revealed 97% (122) were not allergic to the drug used to treat bacterial infection.

The researchers said their findings, published in the Journal of Infection, demonstrate it may be possible for healthcare professionals with no allergy specialism to give an oral dose of penicillin to low-risk patients and monitor them closely afterwards.

They said this method would allow patients mislabelled as being allergic to penicillin to be “de-labelled” in a general healthcare setting, without doing comprehensive allergy tests at specialist clinics.

“By demonstrating that allied healthcare professionals with no previous background in allergy are capable of removing a penicillin allergy label, this study provides a low-cost framework for adoption by healthcare systems.”

Dr Louise Savic, consultant anaesthetist and drug allergy specialist at Leeds Teaching Hospitals NHS Trust, and co-chief investigator of the study, added: “This study demonstrates that a routine programme of de-labelling people who believe they are allergic penicillin, outside the setting of a specialist allergy clinic, is potentially achievable.”

Around six to 10% of the general population in the UK are recorded as allergic to penicillin but previous research has shown true penicillin allergy is rare, affecting only around 1% of the population.

Last year, the Royal Pharmaceutical Society (RPS) advised patients to check their medical record the next time they visit their GP to ensure they are not wrongly labelled as allergic to the drug.

They said people may believe they are allergic to penicillin for a variety of reasons, such as if suffering common side effects of the drug such as nausea or diarrhoea.

For the study, clinicians ran trials at University Hospitals Birmingham NHS Foundation Trust (UHB), Leeds Teaching Hospitals NHS Trust and Oxford University Hospitals NHS Foundation Trust.

People taking part were given an oral dose of amoxicillin – a type of penicillin antibiotic – by a research nurse or a research pharmacist and supervised by a non-allergy specialist clinical consultant, with immediate access to resuscitation facilities if needed.

Results showed 97% were deemed as having no penicillin allergy.

Professor Mamidipudi Thirumala Krishna, chairman of Allergy, Clinical Immunology and Global Health at the University of Birmingham, and chief investigator of the study said: “Inaccurate penicillin allergy labels are a huge burden globally.”

He added: “Penicillin allergy labels are not benign and contribute to antimicrobial resistance, so enabling more patients to safely benefit from penicillin will ease the burden of other antibiotics that are currently being overused and improve quality of clinical care.

“In our feasibility study, we showed how a closely monitored protocol for taking penicillin directly, rather than using a skin allergy test which needs to be delivered by an allergy specialist, was effective in low-risk patients.

“This means they can safely use penicillin in the future.”

The research was funded by the National Institute for Health and Care Research (NIHR).