Question about Food Allergies

What is the likelihood for a person who has no known food allergies to spontaneously develop them as an adult?

from: http://www.todaysgeriatricmedicine.com/archive/0515p8.shtml

I’m going to guess entirely possible. I’ve been having some health issues and both Drs I’ve seen asked if I’ve ever been tested. Twice, both times, non allergic. When I told them this, they both made a point of telling me that it doesn’t mean I haven’t developed some since! In fact, I may have to be tested again!

Not merely food allergies, but any allergies can spontaneously develop or disappear at any age.