What Foods Are Tested in Allergy Testing?

A food allergy is a condition where your immune system treats a particular food protein as it would treat a harmful virus or infectious agent. The immune system responds to these foods by causing:

• Respiratory system (the lungs, nose ,and throat) symptoms such as coughing, wheezing, nasal congestion, trouble breathing, and tightness in the chest.
• Skin symptoms such as hives, tingling, itching, and redness. In babies with food allergies, the primary symptom is often a rash.
• Digestive system symptoms such as abdominal pain, metallic taste in the mouth, and swelling and/or itching of the tongue.

In children, the most common food allergies are:

• Cow’s milk
• Hen’s eggs
• Peanuts
• Tree nuts
• Soy
• Wheat

In adults, the most common food allergies are:

• Peanuts
• Tree nuts
• Fish
• Crustaceans (shrimp, crabs and lobster)
• Mollusks (such as clams, oysters and mussels)

In some cases, food allergy testing may reveal that you have food sensitivity (also called food intolerance), which is less severe than a food allergy. Common food sensitivities include:

• Lactose
• Gluten

Food sensitivity may cause symptoms such as:

• Abdominal pain
• Nausea
• Diarrhea
• Gas

Some of the factors that may prompt you to get food allergy testing include:

• Family history of food allergies
• Other food allergies
• Other types of allergies such as hay fever or eczema
• Asthma

Food allergy testing may involve the following:

• Skin prick test: Your allergist first cleans your forearm. Next, they lightly prick your skin with a small device. They place a small drop of liquid food extract on your forearm skin. Within 15-20 minutes, you may observe a raised bump with redness around it. The allergist marks each test site with a pen to identify the allergen being tested.
• Allergy blood test: Your allergist withdraws blood from a vein in your arm to check for Immunoglobulin E (IgE) antibodies produced in response to an allergy-causing substance.
• Oral challenge test: Your allergist gives you a small amount of the food suspected of causing the allergy. Next, they closely monitor you for any allergic reaction. An oral challenge test confirms food allergy after skin prick and allergy blood tests. Sometimes, people test positive during a skin prick test or blood test but have no symptoms during the oral challenge test.