Anaphylaxis during oral food challenge: can we predict it?

Abstract

Despite being the gold standard for food allergy diagnosis, oral food challenge (OFC) poses an inherent risk of undesirable reactions, including anaphylaxis. Risk factors for severe symptoms remain unclear. This study aims to describe OFC outcomes to identify possible risk factors for anaphylaxis in this procedure. Retrospective evaluation of medical records from patients with suspected IgE-mediated food allergy to cow’s milk (CM) or egg, who underwent OFC in a pediatric hospital (2016-2018). Patients challenged to either raw or processed CM/egg were included. Anaphylaxis was defined according to Sampson et al, 2006. Data were compared through non-parametric tests 125 OFC (97/CM and 28/egg) carried out in 80 patients (median age of 6.5y) were reviewed. Anaphylaxis was observed in nearly one third of the tests (41). Among these, the first complaint was oropharyngeal pruritus. The most affected systems were cutaneous (82.9%), followed by respiratory (78%), and less frequently cardiovascular (9.7%). Most patients achieved clinical resolution of symptoms after one dose of epinephrine, but five patients required additional doses. One patient had a biphasic anaphylaxis. OFC with raw food compared to processed allergen evidenced similar potential to trigger anaphylaxis (p> 0.05). Personal history of asthma or prior anaphylaxis did not increase the risk of anaphylaxis on OFC (p>0.05). Among patients challenged with raw allergens, older age increased the risk of anaphylaxis (p<0.001). OFC is a high risk setting for anaphylaxis regardless of allergen processing or patient’s medical history. Readiness for emergencies is always mandatory, as severe reactions could not be anticipated.