Adult-onset IgE-mediated food allergy at a Winnipeg allergy clinic: a case series

BACKGROUND: It is a putatively understood phenomenon that the overall prevalence of allergic disease has been increasing in recent decades—particularly in industrialized nations. Despite this, there is a relative scarcity of data concerning the development of food-related allergic disease in the adult population. In addition, the paucity of data as it pertains to the Canadian population is particularly marked when compared to other nations. We sought to determine common culprit foods and the reactions they elicited in a series of 14 patients seen in the Winnipeg allergy and immunology clinic. METHODS: We conducted a retrospective review of patients identified by academic allergists in Winnipeg, Manitoba as fitting criteria for adult-onset IgE-mediated food allergy from May 2018–July 2020. We included patients with IgE-mediated symptoms, including the pollen-food syndrome which developed at the age of 16 or later. We collected data regarding the food which induced the reaction, what the reaction was, and any concomitant atopic disease. RESULTS: The most common culprit food identified was shellfish, followed by finfish, pollen-food syndrome, and wheat/flour. The most common reaction experienced was anaphylaxis, followed by food-dependent exercise-induced anaphylaxis and isolated (muco)cutaneous symptoms. With regard to concomitant atopic disease, allergic rhinitis/rhinoconjunctivitis stood out as the most prevalent. CONCLUSIONS: Adult-onset food allergy—particularly with resultant anaphylaxis—is an important phenomenon to recognize, even when patients have previously tolerated the food in question.