Diagnostic value of a medical algorithm for investigation of perioperative hypersensitivity reactions

Background: Evaluation of perioperative hypersensitivity (POH) is challenging, and accurate screening tools are needed to optimize the diagnostic process. We aimed to assess and validate the diagnostic value of a published algorithm (using tryptase and clinical presentation) to identify appropriate individuals for further testing for IgE-mediated POH. Methods: We analysed the clinical presentation (tryptase elevation, cardiovascular, respiratory, skin involvement) of patients proceeding to testing for possible IgE-mediated POH at a single tertiary referral centre, relative to subsequent skin testing and specific IgE results. Clinical presentations by drug class were also determined. Results: In 293 consecutive patients, the use of a published algorithm based on one or more of; (i) defined increase in serum tryptase, (ii) involvement of at least two-organ systems, or (iii) presentation with new urticaria and/or angioedema; was highly sensitive [98.8% (CI95: 95.7–99.9%)] but less specific [34.6% (CI95: 25.7–44.4%)] in identifying patients testing positive on skin testing and/or specific IgE. Presentation with cardiovascular symptoms was also sensitive [89.8%(CI95: 84.2–94.0%)], while the combination of respiratory symptoms and increased tryptase was most specific [85.9%(CI95:76.6–92.5%)]. Respiratory involvement was more common in neuromuscular blocking agent allergy, while urticaria/angioedema was more common in antibiotic allergy. Conclusion: The published algorithm (of tryptase rise, two-organ involvement or new urticaria/angioedema) is highly sensitive, and appropriate as a screening tool to identify patients suitable for testing for IgE-mediated POH.