Why should we de-label ‘penicillin-allergic’ patients?

Penicillin allergy is commonly over-reported and patients are often incorrectly labelled as being allergic to penicillin. Removing incorrect penicillin allergy labels can improve patient care by effectively making penicillin available to patients and reducing unnecessary use of broad-spectrum antibiotics, Mr Hearsey explains.  A detailed allergy history is required to determine whether there is a high or low risk of having a true penicillin allergy. The low-risk group was separated into those eligible for direct de-labelling on history alone and those eligible for direct drug provocation testing.

The British Society of Allergy and Clinical Immunology (BSACI) recently published guidelines to help non-allergists to set up penicillin allergy de-labelling services, he says.

The penicillin allergy de-labelling toolkit contained all of the documentation resources needed to undertake the procedure. The drug provocation test involved giving a dose of penicillin under careful observation.

A total of 56 patients were successfully de-labelled in the pilot study and the next step is to embed this into the standard of care at the hospital.  A key challenge will be preventing the erroneous reappearance of the penicillin allergy label, acknowledges Mr Hearsey.

Read and watch the full series on our website or on YouTube.

The penicillin allergy de-labelling toolkit contained all of the documentation resources needed to undertake the procedure. “It had all of the patient information leaflets, the consent forms, allergy risk-assessment tool and questioning tool as well – so everything we needed to undertake that challenge for the patients”, explains Mr Hearsey.

Most patients were keen to undergo ‘de-labelling’. “The patient information leaflet outlined the benefits of losing that penicillin allergy label and the benefits to their future health needs”, he says. However, a few patients declined to participate in case it prolonged their stay in hospital, he adds.

The drug provocation test involves giving a dose of penicillin – ideally the penicillin associated with the original allergy label – under careful observation. Baseline observations were recorded and then every 15 minutes for one hour.  “If we were unable to identify the index penicillin we would use amoxicillin 500 milligrams”, he notes. “While we were watching the patient we had an EpiPen available and a loud voice to shout the clinical teams if we needed help – if anything did go awry”, he explains.  No immediate reactions occurred but two patients reported later adverse effects – “One patient had a delayed skin reaction at day six and one patient had an episode of thrush”, says Mr Hearsey. The rash on day six was outside the study parameters (which called for monitoring for five days post-test) and it was uncertain whether the episode of thrush was related to the test dose of penicillin.

One of the key challenges is how to prevent the penicillin allergy label from reappearing later, perhaps as a result of another clinician finding it in previous records, Mr Hearsey acknowledges. “With the study materials we make sure to provide the patient with an information leaflet so they can show that to their GP and other healthcare providers. We wrote to the GP and also took their allergy history or label off our system at this point but we have seen that there’s that risk of it reappearing or getting added on a later date if the records aren’t updated in a timely manner”, he says.

In summary, he says: “We’ve shown that this intervention is safe and effective. We were able to de-label 56 patients overall [in the] pilot study, so the next steps are to embed this into our standard of care now.”

Read and watch the full series on our website or on YouTube.

Penicillin allergy is commonly over-reported and patients are often incorrectly labelled as being allergic to penicillin. Removing incorrect penicillin allergy labels can improve patient care by effectively making penicillin available to patients and reducing unnecessary use of broad-spectrum antibiotics, Mr Hearsey explains.  “Usually, [the penicillin allergy label] is acquired in childhood – where they might experience a rash after having a course of penicillin. That might be because of the bacterial or viral infection being managed with the antibiotic rather than the penicillin itself. Patients also misunderstand what an allergy is or a true allergy and therefore report intolerances such as nausea, vomiting diarrhoea or headaches as allergies which then means they can’t have penicillins for the future”, he says.

The overall prevalence of penicillin allergy is estimated to be less than five percent of the population, although up to 15 percent of hospital inpatients report penicillin allergies.  The task of de-labelling incorrectly labelled patients traditionally fell to allergists. “However, due to the number of patients reporting a penicillin allergy now and the clinical time available for allergists to undertake this work it’s just not feasible. So, the British Society of Allergy and Clinical Immunology (BSACI) released guidelines recently in order to help devolve that process so that pharmacists and doctors can undertake this work and …. empower non-allergists to complete penicillin allergy de-labelling”, explains Mr Hearsey.

The study undertaken at the Royal Cornwall Hospital Trust involved taking a detailed allergy history from patients who had penicillin allergy labels, they were stratified according to the likelihood of harm from penicillin re-exposure.  Those at high risk of having a true allergy to penicillin were excluded from the study.  The remainder were separated into those eligible for direct de-labelling on history alone and those eligible for direct drug provocation testing.

Read and watch the full series on our website or on YouTube.