How to Know If You Have A Food Allergy

Food allergy symptoms can range from mild to severe. Someone with a peach allergy, for example, may experience mild tongue swelling or itching in the back of the throat. Others with more serious food allergies, such as shellfish allergies, may develop symptoms like hives, vomiting, or even anaphylaxis shortly after exposure.

When evaluating symptoms after eating certain foods, it's important to understand the difference between a food intolerance and a food allergy:

Food allergy symptoms to look for

Because food allergies can affect multiple systems in the body at the same time, symptoms may appear in several ways simultaneously.

Common systems involved in a food-related allergic reaction include:

• Digestive system – Stomach pain, cramping, nausea, vomiting, and diarrhea are common gastrointestinal symptoms associated with food allergies.
• Respiratory system – Wheezing, coughing, throat tightness, and swelling of the tongue or airways may occur during an allergic reaction.
• Circulatory system – Some people may experience dizziness, low blood pressure, fainting, or a weak pulse during a severe reaction.
• Skin – Skin-related symptoms can range from mild itching or redness to hives and swelling.

Anaphylaxis is a rare but serious and potentially life-threatening allergic reaction that may cause swelling of the airways, difficulty breathing, dizziness, loss of consciousness, or a dangerous drop in blood pressure. In some cases, symptoms can return hours after the initial reaction.

Although severe food allergies are relatively uncommon, recognizing food allergy symptoms early may help you identify potential triggers and reduce the risk of serious reactions.

If you suspect you have a food allergy, the next step is to speak with your healthcare provider about testing and evaluation options.

Food allergy testing is designed to help identify foods that may be triggering an immune response. Healthcare providers may use several methods to evaluate potential food allergies, including blood tests, skin prick tests, elimination diets, and oral food challenges.

Food allergies involve immunoglobulin E (IgE) antibodies, which are produced by the immune system in response to substances it mistakenly identifies as harmful. People with food allergies may have elevated IgE responses to specific foods.

Common food allergens evaluated during allergy testing may include:

• Dairy
• Eggs
• Fruits and vegetables
• Grains
• Legumes
• Meats and seafood
• Nuts and seeds
• Spices

If you believe certain foods may be causing symptoms, food allergy testing can be an important step toward identifying potential triggers and determining whether additional diagnostic assessment is needed.

For some people, food allergy testing may provide enough information to help them identify and avoid potential trigger foods. In other cases, additional diagnostic testing may be recommended to confirm a food allergy and better understand the severity of the reaction.

Diagnostic food allergy testing can be especially important for people with severe allergies, including nut or shellfish allergies, where even trace exposure may trigger a serious reaction.

Because food allergy testing can involve multiple steps, it may help to understand the different methods a healthcare provider or allergist may use during the diagnostic process:

• Oral food challenge – During an oral food challenge, a person consumes a small amount of a suspected allergen under close medical supervision. This type of testing is carefully monitored in case emergency treatment is needed.
• Skin prick test – A skin prick test measures the body's reaction to small amounts of potential allergens introduced just beneath the skin's surface. People with food allergies may develop redness, swelling, itching, or a rash at the test site.
• Blood tests – Blood testing may help measure the immune system's IgE response to specific foods without directly exposing the body to the allergen.
• Elimination diet – An allergist may recommend temporarily removing suspected trigger foods from the diet and gradually reintroducing them one at a time to observe whether symptoms return. Learn more about how to do an elimination diet.

Working with a healthcare provider can help you determine which testing approach is most appropriate based on your symptoms, medical history, and risk of severe allergic reactions.

Living with a food allergy often requires making lifestyle adjustments to avoid exposure to certain foods and ingredients. In some cases, a healthcare provider or allergist may also recommend a treatment plan to help manage symptoms and reduce the risk of severe reactions.

Food allergy treatment plans vary based on the individual, the severity of the allergy, and the body’s immune response. Common treatment approaches may include:

• Elimination – Avoiding foods that trigger allergic reactions is one of the most important parts of managing a food allergy. In some cases, this also means avoiding foods or products that may contain trace amounts of the allergen.
• Medication – Antihistamines may help relieve mild to moderate allergy symptoms such as itching, swelling, or hives. For severe food allergies, a healthcare provider may prescribe an epinephrine injector (EpiPen) to help treat life-threatening allergic reactions, including anaphylaxis.
• Oral immunotherapy – Some allergists may recommend oral immunotherapy, a treatment approach that gradually introduces small amounts of an allergen over time under medical supervision to help reduce sensitivity.

Although managing a food allergy can feel overwhelming at times, identifying your triggers and working with a healthcare provider can help you better protect your health and reduce the risk of serious allergic reactions.