Rash on lips and roof of mouth?

A few times a year, I get a rash on my lips. My lips start out tingly, then overnight they'll become swollen and bumpy. Next it moves to the roof of my mouth. It's painful, but after another day the bumps become just hard, dead skin. My lips then peel for the next few days and the rash on the roof of my mouth just disappears.

I originally thought that it had something to do with the changing of the seasons, but I've been doing some research online and think it might be a food allergy.

The only different thing I ate yesterday was part of a cucumber. I did notice that it made my mouth numb (which is weird, and I stopped eating it and threw it away).

Has anyone ever experienced something like this?