I'm allergic to nickel?

I have 3 ear piercing on my lobes. The bottoms are 2g and the top 2 are regular size. No matter what earrings I put in my top hole, they get infected and bloody and crusty. Why? I use hypo allergenic and nickel free and I've also used stainless steel. They all do the same thing and I can't figure out why. I use stainless steel for my snakebites and they don't do that o_o help?