(CBS) – A north suburban doctor says she has the answer for food allergies: drops of the food that could kill someone placed under the tongue.

Other allergists say it’s a bad idea, CBS 2’s Dana Kozlov reports.

Nine-year-old Stewart Thompson is fighting his food allergies drop-by-drop. He’s allergic to eggs, peanuts and other foods.

And now, Stewart is one of more than 50 allergy patients undergoing a treatment called sublingual immunotherapy, or SLIT, in Dr. Kim Ricaurte’s Winnetka office.

“It’s so easy and convenient, and the science is without a doubt, irrefutable,” she says.

Ricaurte began offering SLIT last January and is the only doctor around Chicago doing so for food allergies.

It works like this: Ricaurte mixes small concentrations of the allergins in bottles, and three drops twice daily are placed under a patient’s tongue.

Concentrations increase with each bottle. After a year or more, if ready, patients try the food to which they’re allergic.

“We don’t promise everyone that the severe allergies will go away completely but they will at least minimize the severity,” Ricaurte says.

It’s widely used in Europe, but it’s not FDA-approved.

“In my opinion it is very much an experimental study and it could be possibly dangerous to someone,” cautions Dr. Anjou Peters of Northwestern Memorial Hospital.

Still, Stewart’s mom is happy with the treatment.

“So far, really good,” Ro Thompson says.

Because it’s not FDA approved, insurance doesn’t cover it so it will cost more than $1,000. SLIT, however, is more commonly used here to battle environmental allergies.