The allergies can show up in unexpected ways.
"I was just going crazy with the itching," says Paula Spurlock. "I just couldn't take it. my head itched, i mean every single thing in me itched," she adds.
The itching, plus migraines and pain, started months after Spurlock received two hip implants. But it would be 2 years, till doctors spotted something unusual on a PET scan for a lung problem, that they would realize she was allergic to her joint implant.
She had to undergo a second surgery to have it replaced.
Spurlock was allergic to the cobalt in one of the implants. Tiny particles of it were wearing off and going into her bloodstream.
"That hip was 68% cobalt, so it needed to be removed. It was causing really bad inflammation and pain and I was obviously allergic to it," Spurlock says.
Dr. Karin Pacheco, an allergist at National Jewish Hospital in Denver, says a growing number of patients are not only allergic to the metals in the implants, but to the bone cement.
Nickel allergies are the most common. It's estimated 15% of people are sensitive to the metal, but most don't know it.
"You can't develop an allergy to somethign to which you;ve never been explosed. And so, for some of these people if they've never had a lot of contact with nickel, they won't know that they're able to develop an allergy until after the implant is put in," Dr. Pacheco says.
Traditional skin patch allergy tests take days to process.
But now, National Jewish Hospital in Denver has developed a fast blood test, so doctors can check for allergies BEFORE surgery.
Dr. Pacheco says, "It's easier. You can send in the blood and it gets developed. You don't need to have somebody available who knows how to do the patch testing."
The hospital has developed a rapid test for nickel allergies, and is now working on one for cobalt. If the Food & Drug Administration gives the green light, the tests will be available nationwide within the next few years.