Newly diagnosed with Nickel allergy

[nrkc1952]

Recent allergy patch test revealed a nickel allergy. I thought to myself "Huh??? Nickel allergy?" I'd never heard of such a thing. And everyone I've spoken to looks at me like I'm nuts. Either that or it's "Oh yes, I can't wear certain jewelry". My issue: I don't seem to have a problem with jewelry, but I've been miserable with an insanely itchy rash for 2 months (seems much longer than that). So, I'm assuming it's dietary nickel. I've done a lot of research (as best as I know how online) and have found varying lists that conflict occasionally. I'm 62 years old and can't believe this is happening to me. What happened? One day I feel wonderful & the next day I am living in Hell. I have not had 1 day since this all began that I haven't itched. The itching sometimes has no visible rash, or it sometimes it just 1 small bump that makes a large section of skin to itch. Breakouts are primarily on my elbows, ankles, feet (between my toes), armpits, wrists (I don't wear a watch or any jewelry), inner thighs & vulva. In the last week I now feel sensitive/burning on my chin and neck. My entire body (skin) burns and stings wherever very warm water touches it. I've tested everything in my house that's silver & shiny and so far, nothing has tested positive except for the nickel coin.
I have many questions, but my dermatologist basically told me to go online to find out what I can. I'm using fragrance free detergent, Aveeno soap (recommended by my dermatologist) - but 1 of my questions is Aveeno soap and bath products are made from colloidal oats. Oats/oatmeal is high in nickel. Should I not be using these products? Help!