These causes aside, some patients do still seem to have a reaction to the stent itself. Early theories suggested that patients were reacting to nickel in the stainless steel used to make the stent. Research has unearthed little evidence to support this theory. Other possible causes are allergic reactions to polymers used to coat drug-coated (drug-eluting) stents and the drugs themselves.
Allergic reactions to stents can range from mild to, very rarely, fatal. If you are a stent patient, you should seek treatment immediately if you develop a rash, breathing difficulties, hives, itching, bruising, joint pain or swelling, muscle pain, fevers or any other symptoms of an allergic reaction.