Millions of people with a common allergy may not actually be allergic at all, first-of-its-kind trial suggests

Daily Mail​

14 hours ago

Millions of people mistakenly believe they are allergic to penicillin, experts warned today.
Around three million Britons are listed on their medical records as having suffered a reaction to penicillin, making it unsafe for them to take it to treat infections, ranging from a dental abscess to a throat infection or meningitis.
Yet, British researchers who tested almost 1,000 patients with the allergy, found almost 90 per cent could actually safely use the antibiotic.
Instead, many were labelled as allergic after developing borderline allergy-like symptoms—such as vomiting or a rash—when given the drug as a child.
Scientists hope the findings could both pave the way for millions more people to benefit from the medication, regarded as one of the most effective antibiotics available, and tackle the threat of antibiotic resistance.
Patients who cannot currently take penicillin for infections are instead treated with a different class of medication—broad-spectrum antibiotics, such as doxycycline.
As broad-spectrum antibiotics target a wider range of organisms, they increase the risk of antibiotic resistance, and are linked with higher rates of potentially deadly hospital-acquired infection, such as MRSA and Clostridium difficile.
Dr Jonathan Sandoe, study lead author and expert in microbiology at the University of Leeds, said: 'Antibiotics have been life-saving drugs since the late 1930s, but we are now in an era where microbes are evolving to resist the effects of current antibiotics.
'The global challenge of antibiotic resistance is causing people to die of common infections, so it is vital to find ways to improve how antibiotics are used.
'Assessing people with penicillin allergy labels is one way we can achieve this.'
He added: 'This research shows that removing incorrect penicillin allergy labels has the potential to improve patient experiences, reduce health costs and tackle bacterial resistance.
'Now, we need to work together with policymakers and patients to help the NHS to address this issue.'
In the trial, researchers tracked more than 300 patients from 51 GP practices in England, all of whom had no history of severe reactions to penicillin.
They were tested for a penicillin allergy, with either an oral dose of the antibiotic or a small injection under the skin.
If there was no immediate reaction, they were given a three-day course of penicillin to take at home, where they were monitored by the research team.
They found 30 patients tested positive for a penicillin allergy, while 335—92 per cent—tested negative.
After three months, 276 patients had the allergy removed from their medical records.
And after 12 months, allergies were removed from the records of 321 patients—88 per cent of the group that was tested.
Writing in the journal Lancet Primary Care, the scientists said 'access to penicillin allergy assessment for patients should be widened'.
As part of the study, researchers also analysed the cost-effectiveness of allergy testing based on the NHS model.
They said that although results may vary in different countries, the study observed 'tendency towards reducing consultations, days in hospital, and emergency admissions' which 'suggest that the penicillin allergy assessment pathway is cost-effective in the short run and increasingly likely to be so over longer follow-up periods'.
Christopher Butler, a professor of primary care at the University of Oxford, said: 'It's this kind of research question that has a huge impact on improving care for individuals, improving cost-effectiveness of what we do as clinicians, and helps us preserve the precious shared resource of of antibiotics to all of us and to future generations.'
Penicillin allergy is often self-diagnosed by people who've had symptoms, such as diarrhoea, vomiting, nausea, headache or bloating, while being treated with the medication.
According to the Royal Pharmaceutical Society, being labelled as allergic to penicillin is associated with a higher mortality rate of an extra six deaths per 1,000 patients in the year following treatment for infection.
This is because the drug saves lives that other medications can't.