People who are allergic to Nickel can have reactions – you should know that even Gold may have some level of Nickel in it – pure gold (24k) earrings may be nickel free though. Ears and wrists (especially ears), are the most problematic areas – so if you have such an issue you should get hypoallergenic earrings. You should go for platinum or high grade gold or silver or surgical stainless steel or titanium – go according to your comfort level and finance.