After receiving several botox injections (4 sessions over a 12 month period with varying number of units) I experience itchyness that becomes unbearable if I do not take my OTC allergy pills. It starts in my hands and feet and then by day 3 it's on my legs and eventually the trunk of my body. I do not use any sort of numbing cream, pain killers or injections prior to the botox injections. Can one shop around for botox with different preservatives?