I should note that I am fairly allergic to nickel, so any impure metals would do SOMETHING to me, but I usually have to be touching the metal for extended periods of time for any adverse reactions. Never heard of issues with breathing it.
For instance, I think kanthal has nickel in it, but I've suffered no ill effects from vaping on my Tobh with kanthal. Might be irrelevant.
I think you have just dicovered the root cause of your illness. If the atty is made of inferior metal you could be getting nickel from it. I would assume ingesting nickel would be much worse than the skin contact.