I was told I was allergic to penicillin as a child. Is the label likely to still be accurate?

Probably not. Up to nine in ten people carrying a penicillin allergy label are not allergic when properly assessed. Many labels originate from childhood reactions — a rash after penicillin during a viral illness is often a viral rash, not an allergy. Allergy also fades over time. The new ASCIA guidelines support GPs risk-stratifying and, for low-risk patients, offering a supervised oral challenge in general practice. It is worth raising with your GP.

What happens in a penicillin allergy challenge in general practice?

For low-risk patients, a GP supervised challenge involves one or two doses of oral penicillin taken in the practice, with a practice nurse monitoring and the GP available if needed. The observation period is around 90 minutes. Anaphylaxis is a small but real risk, so practices need protocols and emergency equipment. If the challenge is negative, the allergy label is removed. Intermediate and high-risk patients — including those with prior anaphylaxis within five years — still need specialist assessment.

Penicillin 'allergy' labels: GPs now cleared to test and remove them

There is a label that around 2.8 million Australians are carrying through the healthcare system — written on their medical records, flagged in hospital notes, influencing every antibiotic prescription they receive. For most of them, it is almost certainly wrong.

The label is a penicillin allergy. And updated national guidelines released this week by the Australasian Society of Clinical Immunology and Allergy (ASCIA) mean that GPs — for the first time — are formally supported to assess, test, and remove that label in general practice.

This matters more than it might first appear.

The problem with carrying the label

About 10% of Australians report a penicillin allergy. The figure most commonly cited in research is that fewer than 1% are genuinely allergic when properly assessed. Some estimates put the rate even lower — up to nine in ten people carrying the label are not allergic when assessed through a supervised challenge.

Where do the labels come from? Many originate in childhood. A rash appears after a course of penicillin during an ear infection or tonsillitis. The rash is noted as an allergic reaction. But in most cases, the rash was a viral exanthem — the immune system responding to the viral illness, not to the antibiotic. The label sticks to the record. The child grows up. Decades pass.

Allergy also fades. The immune response to a drug allergen diminishes over time. A reaction in 1995 may have resolved by 2026 — but the record doesn’t update itself.

The practical cost of this is not abstract. Patients carrying a penicillin label are routinely prescribed second-line antibiotics when penicillin-class drugs would be more effective, better tolerated, or narrower spectrum. Second-line antibiotics are often broader-spectrum, which contributes to antimicrobial resistance — a global public health concern that AU specialists, including the National Allergy Council, are actively tracking. One Australian hospital study found delabelled patients had 4.41 fewer average hospital days and $9,468 lower hospital costs than those left labelled.

What the new ASCIA guidelines change

The updated ASCIA guidelines, developed with the National Allergy Centre of Excellence and incorporating consumer input, set out clearer criteria for who can be assessed and tested in general practice. This is the first time GPs have been explicitly supported to do this work in the community setting, rather than only in specialist allergy clinics.

The process for a low-risk patient looks like this:

History review. The GP takes a detailed allergy history — the original reaction, the time elapsed, any re-exposures since. This determines risk stratification.
Low-risk supervised challenge. If the history is low-risk, the GP can offer an oral challenge in the practice. One or two doses of oral penicillin are given. The patient is observed for approximately 90 minutes by a practice nurse, with the GP available to manage any reaction. Anaphylaxis is a small but real risk, so practices need written protocols, trained staff, and access to adrenaline.
Delabelling. A negative challenge removes the label. Importantly, the documentation needs to follow the patient — updating My Health Record, notifying hospital clinics, and giving the patient a wallet card confirming a negative test, since labels “don’t stick” when people move between GP, hospital, and specialist care.

Intermediate- and high-risk patients — those with a history of anaphylaxis (particularly within the last five years), severe delayed reactions, or complex histories — still need specialist allergy assessment. GPs are not expected to take on every patient; the guidelines are about expanding the GP role for the large low-risk cohort, not removing specialist assessment from those who need it.

Both-and: what makes this genuinely promising and genuinely impractical at the same time

The potential here is significant. With roughly 2.8 million Australians carrying the label, and general practice being the entry point for most of them, moving even a portion of low-risk assessments into the community could reduce antimicrobial resistance burden, improve prescribing quality, and remove a real barrier for patients who have been avoiding penicillin-class antibiotics unnecessarily for years.

But here is the practical problem: there is currently no dedicated Medicare Benefits Schedule item for penicillin allergy challenges in general practice. ASCIA has applied for new item numbers, but the application is pending. Without a dedicated item, practices can bill existing consultation items plus a private fee — which adds out-of-pocket cost and may deter both patients and practices from offering the service.

Implementation is expected to be gradual, starting with staff training and protocol development. Free specialist support is available through the National Allergy Council’s Allergy Assist platform, which connects GPs with remote specialist advice. Professor Michaela Lucas’s Western Australian research found only 9% of health professionals routinely assessing medication allergies met Australian standards — and those who had completed recent penicillin allergy education showed significantly greater knowledge. The training gap is real, and the guidelines acknowledge it.

2 cents: what this means for your terrain this week

If you carry a penicillin allergy label and are not sure where it came from — or if it dates from childhood — this is worth raising at your next GP appointment.

A good starting question: “My penicillin allergy is recorded from when I was a child. Given the new ASCIA guidelines, is it worth reviewing whether the label is still accurate?”

Your GP will take a history. If your background is low-risk, you may be offered a supervised challenge in the practice. If your history is more complex, a specialist referral is the appropriate path.

This is not urgent. It is not an emergency review. But it is a genuinely useful piece of healthcare housekeeping — one that may, down the track, change the antibiotic you receive when you actually need one.

Verdict: yes — this is worth knowing about.