Getting the Facts on Food Allergy Testing

If you have ever experienced red, itchy skin, swelling, vomiting or trouble breathing after eating or coming into contact with a certain food, you may wonder if you have a food allergy.

While diagnosing food allergies can be tricky, an allergist has the training and expertise to know which tests to give you and how to accurately interpret them.

Your allergist will take a thorough medical history, followed by a physical exam. You may be asked about contents of the foods, the frequency, seasonality, severity and nature of your symptoms and the amount of time between eating a food and any reaction.

An allergy skin test may determine which foods, if any, trigger your allergic symptoms. In skin testing, a small amount of extract made from the food is placed on your back or arm. If a raised bump or small hive develops within 20 minutes, it indicates a possible allergy.

Nine kinds of food cause most food allergies:
• Cow’s milk
• Soy
• Eggs
• Fish
• Peanuts
• Shellfish
• Wheat
• Tree nuts
• Sesame

In certain cases, such as in patients with severe eczema, an allergy skin test cannot be done. Your doctor may recommend a blood test. False positive results can occur with both skin and blood testing, but there is another type of test that an allergist can perform if there is any doubt.

To confirm your diagnosis, an allergist may perform a food challenge. Food challenges are done by consuming the food in a medical setting to determine if that food causes a reaction. Do not try this test at home. Anaphylaxis (pronounced an-a-fi-LAK-sis) is a serious allergic reaction that happens very quickly. Without immediate treatment, it can be fatal.

If a reaction should occur during a food challenge, your allergist can spot the symptoms and provide a shot of epinephrine (adrenalin) and expert care.

Once you know which foods you are allergic to, your allergist can help you develop a treatment plan so you can be healthy and safe.

To the Point
• If you have symptoms such as red, itchy skin, swelling, vomiting or trouble breathing after eating or coming into contact with certain foods, it’s important to see an allergist.
• Diagnosing food allergies is tricky, but an allergist knows which tests to give you and how to interpret them.

The AAAAI's Find an Allergist / Immunologist service is a trusted resource to help you find a specialist close to home.

3/4/2024