A growing number of people are allergic to nickel - possibly due to increased exposure to it from cell phones, iPads and the like, and it can cause rashes and other dermatological problems. It's in a LOT of foods, particularly...sorry everyone...chocolate. See, e.g., www.ncbi.nlm.nih.gov/pmc/articles/PMC3667300/.
To actually eliminate nickel and other metals from your diet is virtually impossible, however, you can keep them to a minimum. Here is one of my favorite nickel-free/low nickel recipes from "Garden to Table":
BOK CHOY MUSHROOM STIR FRY
2 t olive oil
1 cut thinly sliced onions
1/2 c chopped red bell pepper
3-4 cloves minced garlic
1/2 t grated ginger
1 lb. coarsely chopped bok choy
1/2 lb chopped mushrooms - pick your favorite or try a variety of different kinds!
2 t fresh lemon juice
Heat oil in a large skillet over medium heat. Add onions, pepper, garlic, and ginger, Stir fry about 1 minute. Add boo choy and onions and story fry another minute. Add lemon juice and stir fry 3-4 more minutes. Enjoy!