Diagnosis and management of patients with allergy to metal implants

Abstract

Cutaneous allergic reactions to implanted metal devices, for example, orthopedic, are well reported in the literature. Also, extracutaneous complications resulting from peri-implant inflammation have been observed in association with metal allergy. Nickel, cobalt, and chromium are the three most common triggers of both cutaneous and extracutaneous allergy-related complications. However, the diagnosis of metal implant allergy remains a challenge, that is, the synopsis of excluding differential diagnoses and the combination of different allergy diagnostic tools is needed. Thus, the management of metal implant allergy is also hampered by clinical uncertainty and unresolved scientific questions.

Keywords:

• allergy
• arthroplasty
• histology
• implant
• lymphocyte transformation test
• metal
• patch test

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Clinical picture: the spectrum of allergic reactions to implanted metallic devices encompasses both skin reactions and non-cutaneous complications with often unspecific symptoms.

• Allergens: major eliciting allergens are nickel, cobalt and chromium – and in case of cemented arthroplasty, also bone cement components.

• Two potential patient conditions: respective allergy exists prior to implantation or the metal releasing device has newly induced allergy by sensitization.

• Diagnostics: there is no definite consensus on the diagnostic steps. However, a general prophetic pre-implant allergy test of future compatibility is not recommended. Metal implant allergy largely is a diagnosis of exclusion (e.g., infection) and results from a synopsis of patch test, histology and additional in vitro assays such as the lymphocyte transformation test.

• Therapeutic management: there are no guidelines regarding the use of hypoallergenic alternatives (such as surface-coated implants or alternative materials) and the use of systemic drugs. Thus, the therapeutic approach is mostly decided on a case-by-case basis.

Notes