I'm pretty sure my hive outbreak was from Botox. How long will this last?

How long does it take for botox to leave the system ? My Dr. has put me on a 10 day prednisone treatment does help but can't work out or get hot in any way or hives explode while I'm sleeping usually around 2-4 am I had Prolotherpy and Botox done in same day could have this been a reaction ? also i have had botox for around 6 years but did change doctors for last 3 times but kinda had some skin issues from last one but didn't connect it. Was almost like i have flea bites but It wasn't of course.