Nickel and Skin: From Allergy to Autoimmunity

Introduction & Objectives: Cutaneous and systemic reactions to various metal implants and medical devices have been well documented. The aim of this review was to focus on the probable common mechanisms of allergy and autoimmunity that may lead to similar clinical outcomes following the growing evidence in the literature of metal and nickel-related systemic, autoimmune or autoinflammatory disorders. Methods: Detailed search of the available electronic databases (PubMed-Medline) was conducted for review of the literature on that topic till the present moment. Results: Multiple reports on the immunological effects of metals including immunomodulation, allergy, or autoimmunity were identified. It was found that metals may act through immunosuppression, immunotoxicity, or as immune adjuvants thus provoking allergy and autoimmunity in susceptible individuals. Both external or internal exposure to metals was observed. Nickel has been identified as the most common sensitizer, and also the most studied one. The coexistence of both allergic and autoimmune symptoms, induced by nickel, has been published, suggesting the autoimmune potential of nickel compounds. Conclusion: Clinical experience and scientific literature together demonstrate that metals may play an important role in the development of autoimmune diseases. While metal implant allergies and complications are on the rise, they remain a diagnostic and therapeutic challenge. Elucidation of their possible mechanisms will contribute to the more successful and safer treatment of affected individuals.