Prosthetic joint allergy testing
There has been a growing trend for doctors referring patients for patch testing to metals and other substances used in prosthetic joint replacement surgery. Two particular clinical scenarios include where people are having problems with their joint replacement, or people who report a strong history of problems with metals, prior to a joint replacement. However, scientific support for testing in these circumstances is limited. Some reports state that pre-implant testing offers little benefit. A useful diagnostic algorithm has been developed by Schalock et al titled “Diagnostic algorithm for the evaluation of suspected metal allergy.”
This is summarized below:
If a person does not have a history of reactions to, or problems with metals, they should not be patch tested prior to prosthetic joint replacement surgery.
If a person does have a definite history of problems with metals, there may be some basis for patch testing these people prior to joint implantation, but the evidence is far from clear. The algorithm mentioned above can assist in the decision of whether to patch test or not. Reactions of testing to metals can also be difficult to interpret, as a positive patch test may not be necessarily relevant to a patients’ clinical scenario. Many patients with metal allergies tolerate their joint replacements.
Clinical expertise is essential to interpret these situations, and decisions such as joint removal should not be based on a positive patch test alone. More research is required in this area.
Patch test series at the Skin and Cancer Foundation Inc:
The Skin and Cancer Foundation have developed a Prosthetic Joint Series for patch testing. This series includes a range of metal allergens, and also other substances that may be used during surgery for a prosthetic joint.
Reference: Schalock P, Menne T, Johansen J, Taylor J, Maibach H, Liden C, Bruze M and Thyssen J. Hypersensitivity reactions to metallic implants-diagnostic algorithm and suggested patch test series for clinical use. Contact Dermatitis, 2011, 66: 4-19.