Clinical Presentation, Triggers, Comorbidities, and Management of Anaphylaxis in the Elderly: A Cross-Sectional Study

INTRODUCTION: Anaphylaxis is a life-threatening, systemic allergic reaction. This study aimed to compare anaphylactic triggers, clinical presentation, and management between elderly (≥65 years old) and non-elderly adults. METHODS: Data from the Cross-Canada Anaphylaxis Registry (C-CARE) from April 2011 to May 2024 were collected, spanning five emergency departments and one emergency medical service across three Canadian provinces. Demographics, trigger, symptom severity, comorbidities, and medication use were assessed. Chi-square tests were used to compare categorical variables between elderly and non-elderly adults, whereas non-parametric t tests were used for numerical variables. RESULTS: Among 1,135 anaphylaxis cases, 90 (7.9%) involved elderly patients. Drug and venom anaphylaxis triggers were more prevalent (p < 0.01) in elderly adults compared to non-elderly adults, while food allergies were less common. Elderly patients were more likely to experience anaphylaxis at home (p < 0.01) and had a higher intensive care unit admission rate (p = 0.04). Use of epinephrine was less frequent in elderly patients (30.0%). CONCLUSION: Compared to younger adults, elderly patients exhibit distinct anaphylactic triggers and have increased ICU admission and lower epinephrine use. Our findings highlight the need for improved recognition, treatment adherence, and tailored management strategies in this vulnerable population.