4 yrs ago I went back for 20 unit of Botox on my forehead 3 months after I had my very 1st treatment with Botox. Ist time the results were a dream, 2nd time I developed hives across my forehead then they moved down my body and my ears were burning for weeks. Same nurse, same dosage used only diff the second time I went for a jog 2 hrs after. I would like to know if I can try another brand? Has it happened before? Would love to try another brand, however my injector will not. What do I do?