I don't know what causes what, but I have Bart and occasionally get hives. Mostly on my hands and face. Nothing to write home about
. When they spring up, I drink a cup of Nettle Leaf Tea and it goes away quick. I also think herx can cause everything. I've gotten to the point where I just assume it's all lyme, it's all herx
Best way to see if it's herx is to back off whatever you're taking and see if symptoms improve. For me, it took a few tries to get it right. You also may need to detox more. Try the nettle, it really helps me.