I've been there, I get hives about twice a year, my body just says FUCK YOU. I am also allergic to blue food dye, I drank 2 - 32oz blue powerades and my lips swelled up like Angie Jolie, too bad so did my throat. I know how bad allergic reactions feel, lots of benadryl, calamine, rantatine, and don't scratch!
Hope its over soon. But you will forever read labels to prevent this hell of a feeling.