Bottles of pills including penicillin are displayed in a row.
Millions of people who think they are allergic to penicillin can likely tolerate the drug, U.K. pharmacists say.
Members of the public may needlessly avoid the highly effective antibiotic, leaving them at greater risk of serious illness from infections, the Royal Pharmaceutical Pharmacy warned in a statement Thursday.
In the U.K., around 4 million people — or 6% of the population — have “penicillin allergy” logged in their medical record.
But when thoroughly investigated, only around 10% usually have a genuine allergy to the antibiotic, the (RPS) said.
Missing out on the 95-year-old drug may — in very rare cases — be fatal.
Research shows that 6 extra people per 1,000 die following treatment for infection if they’re labelled as allergic to penicillin.
And it’s not just a problem across the pond. In the U.S., many members of the public also believe they’re allergic to the antibiotic when they’re likely not, according to the Centers for Disease Control and Prevention.
Some 10% of U.S. adults say they’ve had an allergic reaction to penicillin at some point in their lives. But less than 1% of the population actually produce an allergic response when tested.
Patients — and their clinicians — may believe they have an allergy to penicillin for many reasons.
Common side effects of the drug — like nausea or diarrhea — may be mistaken for an allergic reaction, as may symptoms that can be caused by infection itself, like skin rashes.
In some cases, people who displayed allergy symptoms as children may believe they remain allergic as adults.
But many people — including those who have tested positive for an allergy in the past — can tolerate the drug later in life. The CDC says around 80% of people who have a true penicillin allergy are no longer sensitive a decade later.
Amena Warner, who leads Clinical Services at charity Allergy UK, said its common for adults to believe they still have a penicillin allergy many years after percieved reactions.
“Many people have had a label of having a penicillin allergy from early childhood often after having a rash with antibiotics,” she said. “This label can be carried with them the rest of their lives, without it ever being investigated.”
Many patients thought to have a penicillin allergy will be prescribed what are called “broad spectrum” antibiotics instead. But these can be less effective against some infections — and their widespread use contributes to antibiotic resistance.
The RPS recommends people who find “penicillin allergy” in their medical records seek advice before assuming it is accurate.
Allergic reactions can themselves be severe and even fatal, so it is important for healthcare professionals to properly investigate them.
RPS Spokesperson Ms Tase Oputu said: “Many individuals are at low, or very low risk, of having a genuine penicillin allergy and we often find that after careful investigation that they can take penicillin safely.
“Others, who may have had a severe reaction in the past, will need allergy testing and in some cases may never be able to take penicillin.”