Beta-lactam allergy in Chinese patients and factors predicting genuine allergy

Beta-lactams (BL) are the most frequently reported drug allergy, but the vast majority of patients are found not to be genuinely allergic after evaluation. Few studies have investigated the clinical predictors of genuine BL allergy, and the prevalence in hospitalized Chinese patients is unknown.

Patients admitted to a tertiary hospital in Hong Kong (HK) were analyzed to identify the prevalence and factors associated with the presence of BL allergy labels among hospitalized Chinese patients. A combined cohort of patients having completed allergy investigation for suspected BL allergies in the United Kingdom (UK) and HK were analyzed to identify predictors of genuine allergy.

The prevalence of BL allergy labels in hospitalized HK Chinese was 5%, which was associated with female gender and concomitant non-BL antibiotic allergy labels. The rate of genuine BL allergy patients referred for suspected allergies in the UK and HK cohort was only 14%. History of anaphylaxis and interval of less than a year since the index reaction were independent clinical predictors of genuine BL allergy. The negative predictive value of penicillin skin testing was 90%, confirming the need for drug provocation testing after negative skin testing. There was a high rate of confirmed piperacillin-tazobactam allergy.

The estimated true prevalence of genuine BL allergy in hospitalized HK Chinese is around 0.5%. This high rate of BL mislabeling highlights the need for comprehensive allergy evaluation and screening. History of anaphylaxis and duration since the index reaction are important predictors of genuine allergy. Piperacillin-tazobactam allergy may pose a unique challenge in this population with a high prevalence of suspected allergies, surging antibiotic resistance, and lack of testing available.