The number one metal that causes an allergic skin reaction is nickel.  Lower quality jewelry use lower quality metals and typically contain nickel. About 99% of all people who get an allergic reaction to jewelry is because of it's nickel content.  Metals like Gold, Fine Silver, and Platinum in their 100% pure state are considered 100% inert and hypoallergenic.  Unfortunately, most jewelry is not 'pure' metal and is mixed with other metals to make them stronger and more durable or to add color.  Metals like 14K/18K gold, Sterling Silver, and Stainless steel are all mixed with other metals.like nickel, copper, selenium, and brass.  While rare, some people can be allergic to these metals as well. There is no way to avoid these metals in most jewelry but our jewelry is nickel free and covers 99% of all people who are allergic to jewelry.