Copper hypersensitivity: dermatologic aspects

Area of Science:

• Immunology
• Toxicology
• Materials Science

Background:

• Copper, a transition metal, can form complexes with proteins, potentially eliciting immune responses.
• While copper exposure is widespread, clinically relevant immune reactions are infrequently reported.
• Understanding copper's immunogenic and immunotoxic potential is crucial due to its diverse applications.

Purpose of the Study:

• To comprehensively profile the immunogenic potential of copper and its compounds.
• To review reported immune reactions to copper, including immediate and delayed types.
• To assess the clinical relevance of copper hypersensitivity.

Main Methods:

• Literature review of reported immune reactions to copper.
• Examination of copper's properties as a transition metal and its interaction with biological systems.
• Consideration of diagnostic approaches for copper hypersensitivity.

Main Results:

• Copper has a low sensitization potential, as indicated by predictive guinea pig tests and the local lymph node assay (LLNA).
• Reported immune reactions include immunologic contact urticaria, allergic contact dermatitis, systemic allergic reactions, and contact stomatitis.
• Clinically relevant cases of copper hypersensitivity are rare, especially concerning cutaneous exposure.

Conclusions:

• Despite potential immunogenicity, unambiguous and clinically relevant sensitization to copper is rare.
• Systemic exposure, particularly from copper intrauterine devices and dental prosthetics, is more commonly associated with immune reactions.
• A diagnostic algorithm is proposed to better clarify the frequency of copper hypersensitivity.