No allergy: Hong Kong study finds many ‘wrongly labelled’ patients can take penicillin to fight superbugs

Many people in Hong Kong told they were allergic to penicillin can take the often-used antibiotic without dangerous side effects, a survey has found. A research team at the University of Hong Kong (HKU) discovered that information on patients’ allergies in medical records was mostly wrong or outdated. Now the team is working with the Hospital Authority, responsible for public health institutions, to identify more patients who can be given penicillin without problems. The move is expected to make a difference in the fight against drug-resistant superbugs, identified as a top global health threat by the World Health Organization. More than 8,000 people in Hong Kong are told every year that they are allergic to penicillin and have alerts added to their health records. One in 50 Hongkongers – about 143,000 people – have a label to warn they cannot be given penicillin. Less effective alternatives bring the risk of developing antimicrobial resistance. But Dr Philip Li-hei, who led the Hong Kong Drug Allergy Delabelling Initiative, said most patients labelled allergic to penicillin could take the drug. Researchers in a joint study by HKU Medicine and the UK’s Guy’s and St Thomas’ NHS Foundation Trust in 2019 found that 90 per cent of 1,000 patients in Hong Kong and the United Kingdom said to be allergic to penicillin could be given it without problems. Li, the division chief of rheumatology and clinical immunology and clinical assistant professor at HKU Medicine, said the mislabelling was inevitable because of a lack of medical specialists in allergies in Hong Kong. He explained it was common for doctors and patients to mislabel nonallergic reactions, but most were not confirmed as there was only one allergist in the city’s public healthcare system. Li said the errors could be dangerous as they would affect how patients with bacterial infections were treated. “When patients are falsely labelled as allergic to penicillin, they are forced to take less effective and broad-spectrum antibiotics, making the bacteria more resistant to multiple kinds of antimicrobial drugs,” Li explained. ‘Covid vaccines safe for people with allergies’: Hong Kong medical experts Antibiotic-resistant organisms, dubbed superbugs, are a consequence of overprescription and improper use of antimicrobials. The common MRSA superbug, for example, can cause severe problems such as blood infections and pneumonia. Like other superbugs, it is found in hospitals and care homes, which look after some of the people most vulnerable to infections. “Removing false allergy labels could enable appropriate antibiotic prescription, especially penicillin, and reduce the incidence of superbugs like MRSA,” Li said. He added the mislabelling of patients also put an extra burden on the overstretched healthcare system through the need for longer periods of treatment and increased costs. Superbug: Hong Kong University calls for centralised reporting, more screening More than 300 patients with penicillin allergy labels have been referred to an allergy clinic at Grantham Hospital, in the Hospital Authority’s Hong Kong west cluster, since the delabelling initiative began in 2020. The clinic is staffed by nurses trained to evaluate patients and classify them as “low risk” or “non-low risk” for allergies. Gladys Kwok Suet-kei, an advanced practice nurse, said patients who experienced mild reactions to penicillin, such as headache and itchy skin but with no visible rash, were classified as “low risk”. These patients undergo a half-day skin test and drug test using diluted quantities of penicillin. If they have no reactions for a week, the allergy label is removed. But individuals who had severe reactions, including swelling in the deeper layers of the skin and upper respiratory tract problems, would be classified as “non-low risk” and referred to an allergist. A total of 90 per cent of the 312 people referred to the Grantham Hospital clinic had penicillin allergy alerts removed from their records and none developed serious reactions to the drug afterwards. “Many patients have lived with the allergy labels for decades. Some remain concerned despite passing the allergy tests,” Kwok said. “We spend a lot of time and effort counselling the patients and providing reassurance and confidence.” Li added the Hospital Authority planned to set up more allergy clinics across the city. The findings of the HKU study were published in the US-based Journal of Clinical Immunology: In Practice in September.