Different Methods in Diagnosing Food Allergy

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We all love to eat. I mean, who doesn’t? However, some people don’t enjoy it as much as others because they have food allergies that worry them. So they try to avoid certain foods that trigger the allergic reaction or, worse, cause them into life-threatening situations. So what is a food allergy?

Defining Food Allergy

According to the National Center for Biotechnology Information (NCBI), food allergy is any adverse reaction to food. When you have food allergies, your body has an abnormal response to certain foods you eat, which is triggered by your body’s immune system. It is estimated that food allergies affect 4% to 6% of children and 4% of adults, according to the data gathered by the Centers for Disease Control and Prevention. Food allergies are common in babies and children; however, it is also possible for it to appear in later life. People who have food allergies sometimes suffer the following symptoms:

  • Vomiting
  • Wheezing
  • Trouble breathing
  • Weak pulse
  • Itching or swelling of the tongue
  • Dizziness
  • Constant coughing

Almost any food can cause an allergic reaction, but certain foods are responsible for 90% of all reactions. These include fish, eggs, soy, peanuts, wheat, shellfish, tree nuts, and milk. With all these foods just easily accessible for anyone, it is important to be aware if you are allergic to any of it. There are a lot of ways to check whether a person is allergic to a certain food. Talk to your allergist to know to have a proper diagnosis.

Diagnosing Food Allergies

There are a lot of ways to diagnose food allergies. Your physician will consider different factors before making a proper diagnosis of the condition. Here are some of the factors that your physician will take into consideration:

    • Symptoms

To diagnose whether you have food allergies or not, the doctor will ask for your symptoms. He will ask you which foods seem to trigger your allergic reaction. This will help your physician determine the allergen that will be used in allergy testing.

  • Family History of Allergies

    According to NCBI, compared to having no allergic family members, having a single family member with a history of allergic disease increased the risk of food allergy in a child by 1.4 fold. While having two or more family members with a history of allergic disease increased the risk of food allergy by 1.8 fold. It would be beneficial if you share information about members of your family who have allergies of any kind. This would help your allergist in assessing your situation and what course of action you should take.

  • Physical Examination

    A physical exam is important in diagnosing any medical condition. According to the Asthma and Allergy Foundation of America, during a physical examination for allergies, your allergist will look at your ears, nose, throat, eyes, and skin. They may listen to your lungs to know if you are wheezing, as this would indicate inflammation in your airways. If your physician thinks that you have allergic asthma, then they will encourage you to do allergy testing.


Allergy Tests to Diagnose Food Allergies

Diagnosing food allergies can be complicated as symptoms of the condition vary from one person to another. Food allergic reactions can affect different parts and systems of the body—from the respiratory tract to the cardiovascular system. To determine whether you have food allergies or not, you may need to undergo some allergy tests. Here are some of the tests that your allergist may recommend to know if you have food allergies or not:


  • Skin Prick Test

    A skin prick test, also called puncture or scratch test, checks for immediate allergic reactions to a particular food. In this test, a small amount of allergen is placed on the skin of your forearm or back. The doctor will then lightly prick or scratch the spot with a needle through the drop. If you are allergic to the food, then your skin will develop redness, swelling, and itching in the area where you were pricked within 20 minutes.

  • Blood Test

    Blood tests are usually done to people who have skin conditions or are taking medicines such as antihistamines that could interfere with skin testing. A blood test can measure your immune system’s response to particular foods by measuring the immunoglobulin (IgE), which is an allergy-related antibody. In blood testing, your doctor will take a blood sample and send it to the laboratory. An allergen which is from the suspected food will then be added to your blood sample. Your allergist will interpret your results and tell you the best treatment for your food allergies.

  • Oral Food Challenge Test

    As mentioned in our previous blog entitled “The Different Types of Allergy Tests”, an oral food challenge test is a test that is used to determine whether a person is allergic to a specific food. In this test, samples of the suspected food may be eaten on its own or mixed with other food. Your allergist will decide whether you’ll take the suspected food directly or mix it with other food. He will also be the one who will monitor you should a reaction occur.

  • Elimination Diet

    In this test, you will be asked to eliminate suspected foods in your diet for a given period and then add the food items back into your diet one at a time. This process can help in linking some symptoms to specific foods. It is important to be careful when you do this diet because you might get a severe reaction from a certain food. Consult your doctor first before trying this method.



If you suspect that you have a food allergy, avoid exposure to the food altogether until you visit your doctor. However, if you have eaten something that triggered a mild reaction, you can relieve the symptoms by purchasing over-the-counter antihistamines.

Allergists are trained to handle food allergies to help a patient have a quality life. If you’re looking for an allergist in the south-central Texas region, Dr. Paul Jantzi can help you. He is board-certified in allergy and immunology with prior specialty training in pediatrics and internal medicine. Don’t struggle with food allergies and schedule a meeting now at Brazos Valley Allergy & Asthma Clinic.

Disclaimer: Information on this website is not intended to be used in place of your professional medical advice or treatment. Please consult your doctor or healthcare provider with any questions regarding a medical condition.

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