Whenever we think "metal allergies", we most often blame it to jewelries, belts, and other accessories, which, we can do without. But metal allergies become more serious for people needing knee implants or hip replacements, too.

In one study reported at the American College of Allergy, Asthma & Immunology meeting here, researchers described a patient who had to have revision of his total knee arthroplasty, because he developed an allergic reaction to the cobalt in the implant.

In a second study, a small but significant fraction of patients receiving metal implants for pectus excavatum, or sunken chest, had allergic reactions to metal bars implanted into their chests.

Doctors therefore advise that before receiving implants, patients would have to go through a rigid examination to minimize subsequent complications due to allergies, particularly for patients who are high risk or those who have been sensitized to certain metals.

In cases like these, non-allergenic titanium or stainless steel may be used. Non-metal based implants are also being developed.

For more details on the study discussing the incidence of metal allergies in patients receiving implants, read the ACAAI report, which includes a short video by Philadelphia allergist and asthma specialist, Norman Koven, M.D..