DALES, Drug Allergy Labels in Elective Surgical patients: a prospective, multicentre cross-sectional study of prevalence, nature and anaesthetists’ approach to management

Abstract Background We sought to define the prevalence and nature of patient-reported drug allergies, determine their impact on prescribing, and explore drug allergy knowledge and attitudes amongst anaesthetists. Methods We performed a prospective cross-sectional study in 213 UK hospitals in 2018. Elective surgical patients were interviewed, with a detailed allergy history taken in those self-reporting drug allergy. Anaesthetists completed a questionnaire concerning perioperative drug allergy. Results Of 21 219 patients included, 6214 (29.3 %) (95% confidence interval [CI]: 28.7–29.9) reported drug allergy. Antibiotics, NSAIDs, and opioids were the most frequently implicated agents. Of a total of 8755 reactions, 2462 (28.1%) (95% CI: 29.2–31.1) were categorised as high risk for representing genuine allergy after risk stratification. A history suggestive of chronic spontaneous urticaria significantly increased the risk of reporting drug allergy (odds ratio 2.68; 95% CI: 2.4–3; P Conclusions Almost 30% of UK elective surgical patients report a history of drug allergies, but the majority of reported reactions are likely to be non-allergic reactions. Allergy labels can impact on perioperative prescribing through avoidance of important drugs and use of less effective alternatives. We highlight important knowledge gaps about drug allergy amongst anaesthetists, and the need for improved education around allergy.