Recently I developed hives. I used to get them all the time when I was little ( mostly from medication). This time I had them from head to toe and my hands, feet and face swelled up and my throat started to close. I think that it may have been from taking Zicam(the OTC cold minimizer). What do you think? Also, the ER doctor prescribed Prednisone. I am having some strange side effects from it (my eyes hurt, the throat feels tight and my neck around my throat hurts along with some dizziness and heart flutters, head pain and mood swings). Is this normal?