- Originally derived from a fungus, penicillin antibiotics such as amoxicillin are used to treat common infections, including chest, sinus, ear, urinary tract and skin infections.
- Up to 20% of Australians admitted in hospital say they have a penicillin allergy.
- Read more:
Weekly Dose: penicillin, the mould that saves millions of lives
Why does it matter?
- People who mistakenly think they’re allergic to penicillin may not get the most effective or safest antibiotics to treat their infection.
- They are also at greater risk of developing multidrug-resistant infections or “superbugs”.
- People who receive second-line antibiotics are more likely to have complications, such as antibiotic-induced gut infections.
Why do people think they’re allergic?
- They may have experienced side effects from penicillin, such as nausea or diarrhoea.
- An Epstein-Barr viral infection treated with amoxicillin, for example, causes a fine, red rash.
- But there is no evidence penicillin allergy is inherited.
- Then there are people who have had a genuine and serious reaction to penicillin.
Testing for penicillin
When someone says they have a penicillin allergy, we first get them to explain what happened with the reaction, including to what antibiotic, in what context and how severe it was. Then we perform skin tests to further assess the person’s risk of reaction. If skin tests are negative, we can then give the patient the penicillin in question under supervision (a “challenge”) to see if they react.
- Our study followed 195 patients who reported a penicillin allergy across six Sydney hospitals.
- In the first phase, we assessed 85 people and found 82% weren’t allergic to penicillin.
- In our study, eight weeks after their test, just 54% of participants in phase one correctly knew their penicillin allergy status.
Reducing long waits for allergy tests
- The wait time from someone first being referred to an allergy clinic to having testing can be up to two years.
- We need to improve access to testing and also look at when people can access allergy services.
- We also need to ensure the results of allergy tests translate to the real world so people know their true allergy status.
- Winnie Tong has received funding from Maridulu Budyari Gumal, the Sydney Partnership for Health, Education, Research and Enterprise (SPHERE), Triple I Clinical Academic Group seed grant 2017, and the Balnaves Foundation.
- The authors would like to acknowledge Professor Andrew Carr, their collaborators and participants on this project.