Soaps, detergents and other cleaning agents can build up under a ring or bracelet causing a type of dermatitis. You should remove all jewelry before using soap or detergent.Medications in the wearer’s system, especially certain antibiotics, can also cause jewelry to blacken or discolor.If none of the explanations above are ringing any bells for you, you may consider the possibility that you are in fact “allergic” to sterling silver. Most people with metal sensitivities are actually sensitive/allergic to nickel which can be found in many jewelry-making materials such as sterling silver and even gold. In some rare cases, the wearer’s basic body chemistry can react to the alloys in both gold and silver and cause tarnishing.