First off, what burley has anyone tried that made them dizzy? Almost all aromatics are burley based, and I've never heard of anyone getting dizzy off a peach aromatic, despite what burley was used.
There isa more than just one burley in this world. There are literally hundreds of varietals in the burley category. And, merely four categories on the commercial end.
The reason no one gets nicotine sickness from an aromatic is that the more shit that put on the leaf that makes it smell aromatic, the less nicotine that can be absorbed.
There is also no genetic difference between a burley and a Virginia. They are the same leaf. There is literally no way your body can distinguish a difference between these two leafs. Even the PH is only like 2 steps away from each other, and it is not the same across the boards for all varieties of burley verses flu-cured.
I don't buy any of these claims that they are allergic to one leaf over another. We let Harris, Cigrmstr, get away with saying that he was allergic to reds for forever, even when blenders would tell him that such and such blend that he was raving about has reds in it.
I'm not going to argue with any individuals, but as a blanket statement overall, I call bullshit.
You may like one leaf over another. Just say you don't like this or that. You may even get tongue taxed by one more than the other. That's ok too, just say you prefer one over the other. But, all of that is a far cry from an allergic reaction.