Dr. Susan Waserman of McMaster is leading a study that exposes children with a food allergy to the food that triggers their allergic reaction. Dr. Waserman was featured on the Feb 27 episode of the CBC's The Nature of Things to talk about her work as an allergist. Watch the full episode here.

The frequency of food allergies in North American children has tripled in the last twenty years. Waserman's study exposes children with allergies to the food that triggers their allergic reactions. She says that treatment is nothing new.

“Allergists have been doing desensitization for years,” Dr. Waserman told CBC Radio's Metro Morning.

“What it means is that you’re giving somebody a tiny amount of that substance that they’re allergic to and building them up safely over time, so that they’re about to tolerate a certain amount of that substance.”

At McMaster, they start by giving children very small amounts of the substance, mixing it into a larger portion of another food. Waserman said doing this over the course of a few months could build immunity up to the point where they can tolerate two of three peanuts per day.

In this particular study, Waserman is working with children from five to ten years old. “Based on what we know, the younger the child, probably the better this process is tolerated,” said Waserman.

So far the program has worked with 22 children who now have the ability to tolerate approximately two peanuts per day.

“There’s no question that there’s fear and anxiety [in parents]. And really, we have a close, working relationship with these parents,” said Waserman.

Waserman stressed: Don't try this at home. “The only way that anybody should ever do this is as part of a research study at the present time and done under close medical supervision.”

“It’s not a cure either,” said Waserman. “Previous studies have shown that once the peanut has stopped the allergy does come back in many children. So it’s something that’s got to be ongoing.”

Dr. Waserman says the parents are grateful, no question, but they can still anxious and working together.