Food Allergy

About Food Allergy

Food allergies affect many millions of people worldwide, with estimates in some high income countries of several percent of children and adults. The most common food allergens, responsible for approximately 90 percent of reactions, are the Big 8: milk, eggs, peanuts, tree nuts almonds, walnuts, cashews, pistachios, soy, wheat, fish, and shellfish. Sesame was added as the 9th major allergen in the US in 2023. Peanut and tree nut allergies are the leading cause of fatal food anaphylaxis. The prevalence of food allergy has been increasing, particularly in Western countries, possibly due to the hygiene hypothesis, delayed introduction of allergenic foods, and environmental factors. The LEAP Learning Early About Peanut Allergy trial found that introducing peanut early in infancy to high risk infants reduced peanut allergy by approximately 80 percent, reversing previous guidance to delay introduction; feeding plans for high risk infants are made with a clinician. Symptoms range from mild oral itching oral allergy syndrome to anaphylaxis. Diagnosis involves clinical history, skin prick testing, specific IgE blood tests, and oral food challenge the gold standard. Management usually involves avoiding the trigger food and, for people at risk of anaphylaxis, carrying prescribed adrenaline epinephrine. Signs of anaphylaxis such as difficulty breathing, throat swelling, or collapse are a medical emergency; call your local emergency number. Oral immunotherapy OIT gradually desensitizes patients by feeding increasing amounts of allergen. Palforzia is the first FDA approved OIT for peanut allergy. The monoclonal antibody omalizumab Xolair was approved for food allergy in 2024, reducing reactivity to multiple foods.