Anaphylaxis in older adult patients: a 10-year retrospective experience.

Background: Despite the worldwide increase in life expectancy and the elderly population, very little is known about the characteristics of anaphylaxis in older adults. Methods: A retrospective scan was made of the files of patients who presented at the Allergy Unit of our clinic between October 2011 and October 2021. The study included 971 patients aged ≥18 years who met the criteria for diagnosis of anaphylaxis. The patients were separated into 2 groups of adults (18-64 years) and older adults (≥65 years). Results: The adult group included 887 (91.3%) patients and the older adult group, 84 (8.7%) patients. Comorbid diseases were seen more frequently in the older adults than in the adult group (p < 0.001). Drugs were seen to be the most common trigger of anaphylaxis in both groups, and this was more common in the older adult group (p = 0.039). Food was a more common trigger of anaphylaxis in the adult group than in the older adult group (p = 0.017). In both groups, the skin was the organ most affected, and was less affected in the older adults than in the adults (p = 0.020). Cardiovascular symptoms were seen significantly more and respiratory symptoms significantly less in the older adult group (p < 0.001, p = 0.002, respectively). Admission to the hospital and the intensive care unit was more frequent in the older adult group and rates of adrenalin administration were higher compared to the adult group (p < 0.001 for all). Conclusion: Anaphylaxis in the older adults is generally caused by drugs. Older adults were found to have more cardiovascular symptoms and more frequent adrenalin injections, hospitalizations and intensive care unit admissions.