There's no standard test used to confirm or rule out a food allergy. Your doctor will consider a number of things before making a diagnosis. The following may help determine if you're allergic to a food or if your symptoms are caused by something else:
Feb. 12, 2014
- Description of your symptoms. Be prepared to tell your doctor a history of your symptoms — which foods, and how much, seem to cause problems — and whether you have a family history of food allergies or other allergies.
- Physical examination. A careful exam can often identify or exclude other medical problems.
- Food diary. Your doctor may ask you to keep a food diary of your eating habits, symptoms and medications to pinpoint the problem.
Skin test. A skin prick test can determine your reaction to a particular food. In this test, a small amount of the suspected food is placed on the skin of your forearm or back. Your skin is then pricked with a needle to allow a tiny amount of the substance beneath your skin surface.
If you're allergic to a particular substance being tested, you develop a raised bump or reaction. Keep in mind, a positive reaction to this test alone isn't enough to confirm a food allergy.
Elimination diet. You may be asked to eliminate suspect foods for a week or two and then add the food items back into your diet one at a time. This process can help link symptoms to specific foods. However, this isn't a foolproof method.
Psychological factors as well as physical factors can come into play. For example, if you think you're sensitive to a food, a response could be triggered that may not be a true allergic one. If you've had a severe reaction to a food in the past, this method may not be safe.
- Blood test. A blood test can measure your immune system's response to particular foods by checking the amount of allergy-type antibodies in your bloodstream known as immunoglobulin E (IgE) antibodies. For this test, a blood sample taken in your doctor's office is sent to a medical laboratory, where different foods can be tested. However, these blood tests aren't always accurate.
- Oral food challenge. During this test, done in the doctor's office, you'll be given small but increasing amounts of the suspect food. If you don't have a reaction during this test, you may be able to include this food in your diet again.
- Gupta RS, et al. Childhood food allergies: Current diagnosis, treatment, and management strategies. Mayo Clinic Proceedings. 2013;88:512.
- Ferri FF. Practical Guide to the Care of the Medical Patient. 8th ed. Philadelphia, Pa.: Mosby Elsevier; 2010. http://www.clinicalkey.com. Accessed Sept. 10, 2013.
- Boyce JA, et al. Guidelines for the diagnosis and management of food allergy in the United States: Report of the NIAID-sponsored expert panel. Bethesda, Md.: National Institute of Allergy and Infectious Diseases. http://www.niaid.nih.gov/topics/foodallergy/clinical/Pages/default.aspx. Accessed Sept. 11, 2013.
- Burks W. Clinical manifestations of food allergy: An overview. http://www.uptodate.com/home. Accessed Sept. 11, 2013.
- Food allergy: An overview. National Institute of Allergy and Infectious Diseases. http://www.niaid.nih.gov/topics/foodallergy/Pages/default.aspx. Accessed Sept. 11, 2013.
- Nowak-Wegrzyn A. Clinical manifestations and diagnosis of oral allergy syndrome (pollen-food allergy syndrome). http://www.uptodate.com/home. Accessed Sept. 11, 2013.
- Food allergy: Tips to remember. American Academy of Allergy, Asthma and Immunology. http://www.aaaai.org/conditions-and-treatments/library/at-a-glance/food-allergy.aspx. Accessed Sept. 10, 2013.
- Sicherer SH, et al. Advances in allergic skin disease, anaphylaxis, and hypersensitivity reactions to foods, drugs, and insects in 2012. The Journal of Allergy and Clinical Immunology. 2013;131:55.
- Wisniewski JA, et al. Alternative and complementary treatment for food allergy. Immunology Clinics of North America. 2012;32:135.
You Are ... The Campaign for Mayo Clinic
Mayo Clinic is a not-for-profit organization. Make a difference today.