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Sometimes kids who have been diagnosed with allergies don’t have an allergy at all.It is less common with tree nut and peanut allergies, but more common with milk, egg and wheat allergies.Ken Hammond/The Associated Press

If you're the mother of a kid with an allergy, you know how allergies affect not just your child, but your whole family. What you eat at home, what to pack in school lunches, how to manage birthday parties – it all has an impact. I know all about it. I'm both the mother of a 14-year-old with a peanut allergy and a clinical immunologist in the Division of Immunology and Allergy Paediatrics at SickKids.

My colleagues and I are engaged in ambitious research, education and clinical work, from looking at prevention of allergies, to exploring ways to identify molecules in the blood which may predict or reduce the risk and severity of anaphylaxis in a particular patient.

But there's something else that's a particular focus for me. It's taking away worry, by rigorously investigating whether the child actually is allergic to certain foods, or if an earlier diagnosis is no longer pertinent, because a child has outgrown the allergy – this is less common with treenut and peanut allergies, but more common with milk, egg and wheat allergies.

That's right: Sometimes kids who have been diagnosed with allergies don't have an allergy at all.

For a variety of reasons, some children may be labelled with a food allergy, but actually not have that particular food allergy.

For instance, your baby could have developed a rash due to a virus coincident with the introduction of a new food, and the allergy label stuck. Or, some antibiotics and other medications can cause a rash or allergic reaction that mimics food allergy.

When a mistaken allergy diagnosis is discovered, I call it "de-labelling," because it removes the allergy "label."

When de-labelling happens, life gets simpler. Things such as enjoying muffins made with eggs as a family on Saturday morning become possible. Even if our investigation indicates that a child still has some allergies, but not all the ones originally suspected or diagnosed, their allergies become less life-limiting.

When we see a child with potential food allergies, we may recommend skin testing and blood testing, and in the case of food allergy, possibly an oral 'food challenge' which we conduct in a controlled setting. We can safely challenge children to suspect foods in a safe and controlled environment. It's a wonderful part of my practice to be able to tell parents that their child is not allergic!

Parents who suspect their child of having a food allergy should consult with their allergist regarding the applicability of such tests and the need to repeat them. The discussion should focus on the degree of certainty of the diagnosis and the possibility of outgrowing the condition.

Food allergies affect approximately 5 per cent of children, which, in Canada, works out to about one kid in every classroom.

Severe allergic reactions are unfortunately on the rise – over the past 15 years, there's been an approximate 18-per-cent increase. With increased information on the prevention of allergies in children, as well as with thoughtful testing, resulting in de-labelling, the hope is to reduce the incidence of food allergy over time and decrease the stress and worry for all families.

Dr. Adelle Atkinson is a staff physician in immunology and allergy at The Hospital for Sick Children.

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