Four million Brits WRONGLY believe they’re allergic to penicillin… and it can be catastrophic. JOSA KEYES was among them – and tells the vital step you must now take

Millions of people in the UK have a penicillin allergy label on their medical records and I’m one of them. This means that the most effective treatment for a wide range of bacterial infections is not available.

You might think this isn’t important and that lots of alternative antibiotics are equally effective. But you’d be wrong – not only are antibiotics in the penicillin family often still the most valuable option, but they’re less likely than alternatives to cause side-effects. So you really don’t want to rule them out unless you have a serious allergy.

Yet as many as nine in ten people – about four million of us – who believe they’re allergic to penicillin are not, according to the charity Antibiotic Research UK.

In fact, this 90 per cent of us with a penicillin ‘allergy’ will actually have grown out of a reaction we had in childhood, or had a reaction to penicillin specifically related to having glandular fever (as in my case), or mistook a side-effect or unrelated symptom for an allergy.

Indeed, 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. This ‘allergy’ is then added to their medical notes without testing or further questioning. And there it usually stays.

The Royal Pharmaceutical Society reports that simply 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, as the drug saves lives that other medications can’t.

The problem is, how do we ensure that those who are genuinely allergic keep the warning on their medical notes, while removing it from those who aren’t?

Over the entire population, this ‘de-labelling’ has the potential to reduce needlessly prolonged hospital stays and hospital-acquired infections, saving the NHS money.

When Alexander Fleming, a professor of bacteriology at the University of London, breezed off on holiday in 1928, he had no idea what world-changing event would occur in his lab at St Mary’s Hospital in Paddington.

Back at work on September 3, he glanced at a mouldy Petri dish where he’d been growing Staphylococcus bacteria, noticing an unusual clear margin around the fluffy green spot.

By chance, scientists in the same lab were studying the effects of moulds on the lung, and a rare strain of Penicillium notatum – a fungus – had transferred to Fleming’s dish, where it was obliterating the infection-causing bacteria as fast as it could.

Fleming’s findings saw him awarded the Nobel Prize in 1945, when the new penicillin drugs – with their ability to treat previously fatal bacterial infections such as chest infections, syphilis and gonorrhoea – became widely available.

The penicillin family remains the best treatment for many bacterial infections, although different antibiotic compounds have since been developed.

I was 17 when I developed a chronic sore throat after visiting my 13-year-old cousin, who was in bed with glandular fever.

Our GP diagnosed tonsillitis and gave me repeat prescriptions for amoxicillin (a form of penicillin). I didn’t get better so he gave me more.

Still feeling rough, I went to stay with a friend in Norfolk, waking the first morning covered head to toe in itchy raised red bumps. My friend’s mum, a GP, examined me and had me tested. Glandular fever.

Back home, I went straight to bed, waking up very white and puffy, covered in small purple bruises. No one appeared worried by this – it was the 1970s – and I gradually recovered.

Only recently have I understood what happened.

The National Institute for Health and Care Excellence reports: ‘Maculopapular rashes [small red spots that merge into patches – which can look like hives, a symptom of allergy] commonly occur with ampicillin and amoxicillin, but are not usually related to true penicillin allergy. They almost always occur in patients with glandular fever. Broad-spectrum penicillins should not therefore be used for “blind” treatment [without testing for bacterial infection] of a sore throat.’

In other words, the rash I suffered wasn’t a symptom of a penicillin allergy, it was a reaction to the drug linked to the glandular fever virus.

There were no further antibiotic-related events in my life until 1992 when, six months pregnant with my second child, I developed a urinary tract infection. As this can lead to early labour, I was given an antibiotic – I’m not even sure which one.

Within hours, I was covered in itchy red blobs that gathered together, particularly uncomfortably over my bump. That was it. I believed I was allergic and the label was applied.

It didn’t matter that doctors hadn’t actually said so. I was convinced and determined never to take penicillin again.

Now I’m in my 60s, I want to be able to access the best possible treatment should the need arise. So I need to get the penicillin allergy label removed if it’s unsuitable.

In 2022, in an effort to speed up this vital de-labelling, the British Society for Allergy and Clinical Immunology set out its guidelines for penicillin allergy de-labelling services, for non-allergists working in hospitals.

Ideally, GPs will refer patients to a de-labelling clinic as they become available, but the UK has the fewest consultant allergists per head of population in the developed world, hence the need to rely on non-specialists, says Dr Sophie Farooque, a consultant allergist at Imperial College Healthcare NHS Trust in London.

She and her colleagues have recently set up one of the first such clinics. So far, the number of people they have de-labelled is tiny but the future potential is huge. The clinic uses a two-tier approach. First, the pharmacy team works through a checklist, including a patient’s medical records.

For instance, they might have been prescribed amoxicillin – without realising it was in the penicillin family – and experienced no problems.

Other questions will focus on symptoms which led to the initial labelling, such as nausea, type of rash, tummy pains, headache or a strange taste.

If the patient is considered low or no risk, they will then be given a dose and observed.

Patients about whom there are any doubts are referred to Dr Farooque’s clinic for further investigation, including skin tests where small quantities of penicillin are injected under the skin to evaluate the reaction. The clinic is held on a day ward, ensuring swift treatment if a patient has an allergic reaction.

This is not going to be a quick fix for the millions wrongly labelled as allergic to penicillin – although there are future plans for a national allergy strategy, says Dr Farooque.

In the meantime, if you have a penicillin allergy label on your notes which you think may be inaccurate, you could ask your GP to contact the Imperial de-labelling clinic, advises Dr Tom Swaine, an infectious diseases specialist at Imperial.

I’ll ask my GP to refer me as soon as the clinic is fully up and running, just in case I ever develop the kind of infection for which the penicillin family is the best treatment.