Re-testing for Antibiotic Allergies

People who have grown up believing they have an allergy to antibiotics will now be able to be safely tested and reassessed, with the opening of Victoria’s Austin Hospital antibiotic de-labelling clinic.
Clinic coordinator Dr Jason Trubiano says people would sometimes have had a strange reaction in childhood that was mislabelled as an allergy. Of the 20 per cent of people who came to hospital believing they had an allergy to antibiotics, up to 90 per cent of them did not.
"This can be very limiting if, for example, they think they are allergic to penicillin and they have cancer or need a liver transplant, if you're allergic to penicillin it potentially excludes many drugs," he says.
"When people are labelled as allergic we often have to use second-line drugs."
"Any infection in a patient that has a lowered immune system is at risk and in that situation we want to give them the best antibiotics, so if we can remove a penicillin allergy label and give them the penicillin antibiotic to a bug that's going to work against it, then we want to do that at all opportunities."
Patients with recurrent infections or a high risk of developing one - such as cancer and organ transplant patients - undergo a detailed consultation of their medical history, then an extensive skin-prick test using a few drops of the antibiotic.
If there is no allergic response, patients are given a small amount of the drug under the skin and if the results are still negative, they are carefully monitored after being given an antibiotic tablet.
If all the tests are completed with no reaction, the patient is given the all-clear.
Dr Trubiano says he was in the early stages of developing a simpler test for antibiotic allergies.
"We'd like to make it as easy as possible in the future and one way would be able to diagnose this in a test tube and we're looking at trying to measure a patient's white blood cell response or immune response to antibiotics in a test tube," he says.
He also stressed it was just as important to establish if a person's allergy label was correct, because 50 per cent of the very severe and rare adverse drug reactions that needed hospitalisation were caused by antibiotics.
Dr Trubiano has so far tested 60 patients and only one has returned a positive result for an antibiotic allergy.
"They're very happy that when they go to their GP the next time when they want to have penicillin for their chest infection, they can take that safely, so people are very positive, we've had great responses from our patients so far," he says.
This New York Times op-ed Are You Really Allergic to Antibiotics? is an interesting read, a first-person take on a doctor treating a patient who thought she may have an antibiotic allergy, and whose treatment could have had a very different outcome had she been allowed first-line treatments.