HomeAsk the allergist: Your questions answered – January 2020

Ask the allergist: Your questions answered – January 2020

January 10, 2020

Ask the allergist is a regular feature in our newsletters where Dr. Julia Upton answers your questions!

Dr. Upton
Dr. Julia Upton

Dr. Julia Upton is a Canadian allergist who is on staff at Toronto’s SickKids Hospital in the Immunology and Allergy Department. She is an Assistant Professor in the Department of Paediatrics at the University of Toronto and is the Section Chair of Food Allergy and Anaphylaxis with the CSACI. Dr. Upton is also a member of our Healthcare Advisory Board.

Please note: Dr. Upton is answering as an individual allergist and her answers do not constitute an official position of her affiliated organizations. Her responses are for informational purposes only and do not constitute specific medical advice, recommendations, diagnosis, or treatment. Please talk to your doctor about any concerns or questions you may have regarding your own health or the health of your child.

This month she answers your question about food allergy testing.


Is it possible to have a serious reaction during skin testing and what are the alternatives?

It is very rare to have a serious reaction to skin prick testing, estimated at less than 0.02%. Food allergy testing can also be performed by blood tests, although skin prick tests and blood tests are not interchangeable. Skin and blood tests are just one piece of the assessment of food allergy. These tests can be positive even if someone does not have an allergy.

After patient history questions and testing, it still may be unclear if someone has a food allergy or if they have outgrown it. To confirm the diagnosis of allergy or to show someone is not allergic, an oral food challenge (OFC) may be done under medical supervision. In an OFC, an allergist gives a person increasing amounts of the food they may be allergic to, in timed intervals.

If you suspect that you or your child has an allergy, it is important to see a doctor. Your doctor can refer you to an allergist, a physician specializing in the diagnosis and treatment of allergies.

Thank you, Dr. Upton, for your insightful and helpful answer!


Learn more about diagnosing a food allergy and some of the ways a diagnosis is made, including patient history, skin prick test, blood test, and oral food challenge on our diagnosis page and our topic sheet.


Do you have a question you’d like to ask Dr. Upton in the months to come? If so, please send it along to us at info@foodallergycanada.ca.

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