This second article on food allergies focuses on food allergic reactions involving specific immunoglobulin E (IgE) mechanism within the immune system. An IgE-mediated food allergy diagnosis requires both the sensitization (positive test) and the clinical signs and symptoms consistent with IgE-mediated food allergy response. Having the confirmed diagnosis and management plan is crucial because the signs and symptoms appear rapidly after every ingestion of a food with the potential to progress in severity to a life-threatening situation, anaphylaxis. A clear understanding of what constitutes a food allergy, specifically an IgE-mediated food allergy, will facilitate clear communication among healthcare professionals, patients and caregivers, and those in the public.