Do you think you are allergic to penicillin? There is a good chance that you are mistaken

Are you allergic to penicillin? Maybe you have a friend or relative who is? With about one in ten people reporting penicillin allergy, this is not surprising.

Penicillin is the most commonly reported drug allergy. But the key word here is "reported". Only about 20% of these 10% have a real allergy to penicillin – so the figure would be one in 50 rather than one in ten.

People may have symptoms that they think are the result of taking penicillin, but are not really related. If these symptoms are not the subject of research, they continue to believe that they should avoid penicillin.

Read more:
Weekly dose: penicillin, the mold that saves millions of lives

This can become a problem if a person is sick and needs to be treated with penicillin. Penicillin and related antibiotics are the most common group of drugs used to treat a wide range of infections, from chest, throat, urinary tract, skin and soft tissue infections.

Overestimation of penicillin allergies is also not ideal because it implies that patients are treated with a wider range of antibiotics than necessary, which contributes to the problem of antibiotic resistance.

Yes, penicillin comes from mold

To better understand why so many people think they are allergic to penicillin, we need to review a brief history of this drug.

Penicillin (benzylpenicillin or penicillin G) was discovered for the first time in 1928 and used for the first time in 1941.

It was developed from a mold, as is the case today. The liquid nutrient broth in which the mold has developed has been drained and the penicillin has been purified.

In the 1930s and 1940s, and even in the 1960s and 1970s, purification techniques were not as effective as today. Many early allergic reactions are therefore thought to be due to impurities in penicillin-based products – particularly injections.

Penicillin and the range of antibiotic compounds that followed have revolutionized the way we treat bacterial infections.

This has led to widespread, and sometimes inappropriate, use of these drugs. Antibiotics do not work against viruses, but are sometimes prescribed for bacterial infections that occur in people with viral infections such as glandular fever.

We know that the use of penicillin in a person with glandular fever can cause a rash that looks like penicillin allergy but that is unrelated.

People can report to their health care professionals symptoms that resemble a penicillin reaction. Perhaps these symptoms are not studied thoroughly because they take time and can be expensive: they are simply due to the common allergy to penicillin.

In addition, some people perceive other adverse effects of a penicillin antibiotic, such as nausea or diarrhea, as an allergy, while it is not actually in effect allergy symptoms.

From that moment, the penicillin family will not be used to treat these patients.

Read more:
We know that bacteria become resistant to antibiotics, but how does this happen?

The problem of antibiotic resistance

An allergy to penicillin may also limit the use of certain other antibiotics that can cause a cross reaction with the allergy.

A cross reaction occurs when the chemical structure of another antibiotic is so similar to the structure of penicillin that the immune system becomes confused and recognizes it as the same thing.

To avoid this, doctors should consult antibiotics belonging to other clbades of drugs when they prescribe patients with documented allergy to penicillin.

But we must be careful when we take a wider range of antibiotics. Indeed, the more bacteria exposed to antibiotics are numerous, the more likely they are to develop resistance to these antibiotics.

To cope with the growing problem of antibiotic resistance, we are now trying to limit antibiotics as low as possible to the lowest level that kills specific bacteria.

We do not destroy tiny ants in our gardens with a mbad, so we use as much as possible a narrow-spectrum antibiotic to conserve broad-spectrum antibiotics for serious and complex infections.

The penicillin family contains narrow-spectrum and broad-spectrum antibiotics. Excluding this family and its "cousins" when we do not need to do so can limit the choice of antibiotics and increase the chances of making other antibiotics less useful.

Can I be tested?

Studies show that allergy to penicillin decreases over time. So, even if you have had a real allergy to penicillin, it may have disappeared for several years.

Under the guidance of your doctor, it is possible to get tested to find out if you are allergic – or allergic – to penicillin.

A scratch skin test involves injecting a small amount of penicillin and monitoring the reactions. Emergency drugs will be available in case you have a serious reaction. Your doctor will probably refer you to an allergist to do so.

Read more:
Common rashes and what to do about them

If you have been told that you are allergic, you must first try to find out when the reaction occurred and what happened in as much detail as possible.

Inform your general practitioner of all this information and he can then decide if a skin test may be appropriate.

Do not try a test dose at home – the risk of a lethal reaction is not worth it.

And if you think you are allergic to penicillin, tell every health professional (doctor, pharmacist, nurse, dentist, etc.) that you are in contact with.