Nearly 10 per cent of Australians mark themselves as allergic to penicillin – but new research shows 90 per cent of them might be able to take the drug with absolutely no ill effects.

Austin Health experts on Monday released their review into the national antibiotics guidelines, which ultimately recommend those who believe they’re allergic to get re-checked.

The false belief can stem from two places, the Melbourne health clinic’s Misha Devchand and Jason Trubiano wrote.

One is the allergy could have been falsely diagnosed in the first place.

A patient could report a side effect like feeling sick or nauseous, which isn’t a true allergic reaction.

Secondly, it’s an allergy that fades with time.

The report estimates 50 per cent of patients will shed their allergy by the five-year mark (after the initial reaction).

“Not only may most penicillin allergies recorded be inaccurate, but many penicillin allergies wane over time,” Ms Devchand said in a statement.

“Half of people allergic to penicillin will lose their allergy over five years, and 80 per cent over 10 years.

“If you think that you are allergic to penicillin, it may be a good idea to have your allergy reassessed.

“Maybe you can be ‘de-labelled’ – that is, having the allergy removed from your health record.”

So why is the finding important?

If patients mark themselves as allergic to penicillin, they’re likely to be prescribed a different antibiotic that might not be exactly what’s required to treat their condition.

It’s likely to be a broad-spectrum antibiotic, which then feeds into the growing global problem of antibiotic resistance.

The patients, if treated with a different, less-effective drug, can sometimes see their hospital stays blow out, experience more readmissions, surgical site infections, and trips to intensive care units.