Matt, I’ve never heard of anyone allergic to gold which I believe is
an inert material. Now the various alloy metals that are added to
achieve differences such as karat, color, workability, etc are
renowned for being reactive, i.e., nickle, copper, etc. Usually
allergic problem can be overcome by simply moving from 14K to 18k or
22k or, as you say using a coating, or even through depletion
techniques. Youy have a real proglem. Cheers from Don at The Charles
Belle Studio in SOFL where simple elegance IS fine jewelry!