IGHE and allergic disease: The severity of the allergic reactions is unpredictable and, while generally regarded as a safe procedure in qualified settings, severe reactions can and do occur during OFC to different foods in patients with varying degrees of IgE sensitization.27 The majority of severe reactions occur when less than half of the challenge food has been ingested.27 Furthermore, OFCs require significant resources and a highly skilled clinical team experienced in this procedure and prepared to treat severe allergic reactions including severe anaphylaxis.