Oral Food Challenges: A Retrospective Review of A Canadian Paediatric Allergy Clinic

Abstract

Abstract BACKGROUND: Food allergies in children can be life threatening and require prompt treatment with epinephrine. The gold standard for food allergy diagnosis is an Oral Food Challenge (OFC). OBJECTIVES: To demonstrate the safety of OFCs for diagnosing and monitoring food allergies in a Canadian community paediatric population. DESIGN/METHODS: Retrospective review of 500 paediatric patients that underwent 684 OFCs to a variety of foods from November 2006 to December 2013. Data collected from the patients includes demographics; the food challenged; reasons for the OFC; reactions experienced during the OFC; medical intervention performed; and whether the patient should continue eating the food challenged (OFC success). Anaphylaxis was defined using the World Allergy Organization criteria – i.e. dermatologic and cardiovascular or respiratory involvement after food ingestion; or two of dermatologic, cardiovascular, respiratory or gastrointestinal involvement after a likely allergen; or cardiovascular involvement after a known allergen. Mild reactions involved only 1 non-cardiovascular system; and moderate reactions involved more than 1 non-cardiovascular system, but did not qualify as anaphylaxis. Systems observed included the dermatologic, upper and lower respiratory, gastrointestinal, cardiovascular, and behavioural systems. RESULTS: Of the 684 OFCs performed, there were 584 OFCs (85.4%) where the patients were successful at eating the food. Reactions occurred in 274 of 684 OFCs (40.1%), including 161 mild reactions (58.8% of reactions), 56 moderate reactions (20.4% of reactions), and 57 anaphylactic reactions (20.8% of reactions). Medical intervention was required in 74 OFCs (27.0% of reactions). All OFCs with no reaction were successful and all OFCs with anaphylaxis were not successful. OFCs with mild and moderate reactions had equivalent odds of being successful (OR [95% CI] = 0.01 [0.0003, 0.08] and 0.006 [0.0001, 0.04], respectively). Most reactions occurred within six hours of exposure to the food (267 of 274 reactions; 97.4%). The most common foods challenged were peanuts, eggs, and cow’s milk. The reasons for the OFCs were to diagnose an allergy (49.7%), monitor outgrowth of a diagnosed allergy (43.7%), or due to a family member having an allergy (6.6%). CONCLUSION: In this community practice setting, patients undergoing an OFC were able to eat the food afterwards in 85.4% of the cases. Reactions occurred in 40.1% of OFCs. Anaphylaxis occurred in 8.3% of OFCs (57 of 684 OFCs). Most patients reacted within six hours of exposure. The majority of patients undergoing OFCs did not require treatment. OFCs provide a safe environment to diagnose and monitor food allergies in children.