A food allergy happens when the immune system mistakenly sees certain food proteins as harmful, causing an allergic reaction. More than 170 foods can cause these reactions, but some of the most common ones include eggs, milk, peanuts, tree nuts, fish, shellfish, soybeans, and sesame.
Symptoms of a food allergy usually show up within minutes to two hours after eating the food and can range from mild, like hives or digestive problems, to life-threatening. Over 20 million people in the United States, both adults and children, are affected by food allergies. While there’s no cure, managing and avoiding allergens, along with medication to ease symptoms, can help people live comfortably.
There are two main types of food allergies: IgE-mediated and non-IgE-mediated. Both involve the immune system, but they differ in how the body reacts. IgE-mediated allergies involve making immunoglobulin E antibodies that release chemicals like histamine, causing symptoms soon after eating the allergen. Non-IgE-mediated allergies involve different immune responses, often taking longer to show symptoms and primarily affecting the gut.
Food allergies are not the same as intolerances. Allergies trigger immune responses, while intolerances mainly involve digestion. Food allergy symptoms can range from mild to severe and affect several body systems, with possible indicators including a severe reaction called anaphylaxis, which needs immediate medical attention.
Food allergies occur because the immune system mistakingly reacts to specific food proteins and produces antibodies known as IgE. When these antibodies bind to immune cells, they release chemicals that cause allergic symptoms. Non-IgE-mediated food allergies involve different immune cells and proteins, leading to gut inflammation and symptoms like vomiting and diarrhea.
Researchers continue to study why some people develop food allergies, with both genetic and environmental factors playing a potential role. Certain risk factors, such as your gut microbiome (the collection of microbes in your GI system), might increase the likelihood of developing allergies, as it influences your digestive health and immune response.
Diagnosing food allergies involves working with an allergist who will review your medical history and conduct allergy tests to determine specific triggers. Once diagnosed, you’ll develop a management plan, including avoiding allergens and preparing for emergencies. Strictly avoiding cross-contact with allergens is crucial to prevent reactions.
For severe reactions like anaphylaxis, carrying an epinephrine auto-injector is essential. Antihistamines can help manage mild symptoms, and in emergencies, corticosteroids might be given to reduce inflammation. Oral immunotherapy, such as Palforzia for peanut allergies, involves introducing small amounts of the allergen to build tolerance.
Biologic therapies like Xolair may help increase tolerance to allergens and reduce allergic reactions. While there’s no way to prevent food allergies in adults, there is emerging evidence on possible prevention in infants and children. People with food allergies may also have other immune-related conditions.
Living with food allergies requires constant management, but it doesn’t have to affect your quality of life. By avoiding allergens and having an emergency action plan, most people with food allergies can lead active lives. If dealing with stress or anxiety due to food allergies, consulting with a healthcare provider can offer support and resources to manage the condition.
