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Karen Appold’s cover story, “Copper,” in the September 2013 issue, offers an exciting and encouraging development in the struggle to prevent hospital-acquired infections, but I have two concerns. As copper tarnishes, it forms a surface patina of copper hydroxide and copper carbonate. Would this patina act as a physical barrier, preventing bacteria from coming into contact with elemental copper and inhibiting the antimicrobial effect? If so, the obvious solution is to polish the surface frequently enough to prevent tarnishing.
The second concern regards the use of copper-nickel alloys. Many people are sensitive to nickel, [with reactions that] usually manifest as contact dermatitis. A study by the North American Contact Dermatitis Group (NACDG), conducted between 1992-2004 and involving 25,626 patients who were patch-tested, showed a prevalence of nickel sensitivity of 18.8% in 2004, increased from 14.5% in 1992.1
With a current U.S. population of approximately 317 million, a prevalence of 18.8% would mean nearly 60 million people with nickel sensitivity. Extrapolating from the NACDG study, the rate is probably actually higher. Medical devices made with copper-nickel alloys that contact the patient’s skin would cause contact dermatitis, and implanted devices would have the potential for more severe allergic reactions.
I simply urge foresight and caution in the use of various copper alloys for medical applications.
Rod Duraski, MD, MBA, FACP, medical director, WGH Hospital Medicine, LaGrange, Ga.
Reference
Karen Appold’s cover story, “Copper,” in the September 2013 issue, offers an exciting and encouraging development in the struggle to prevent hospital-acquired infections, but I have two concerns. As copper tarnishes, it forms a surface patina of copper hydroxide and copper carbonate. Would this patina act as a physical barrier, preventing bacteria from coming into contact with elemental copper and inhibiting the antimicrobial effect? If so, the obvious solution is to polish the surface frequently enough to prevent tarnishing.
The second concern regards the use of copper-nickel alloys. Many people are sensitive to nickel, [with reactions that] usually manifest as contact dermatitis. A study by the North American Contact Dermatitis Group (NACDG), conducted between 1992-2004 and involving 25,626 patients who were patch-tested, showed a prevalence of nickel sensitivity of 18.8% in 2004, increased from 14.5% in 1992.1
With a current U.S. population of approximately 317 million, a prevalence of 18.8% would mean nearly 60 million people with nickel sensitivity. Extrapolating from the NACDG study, the rate is probably actually higher. Medical devices made with copper-nickel alloys that contact the patient’s skin would cause contact dermatitis, and implanted devices would have the potential for more severe allergic reactions.
I simply urge foresight and caution in the use of various copper alloys for medical applications.
Rod Duraski, MD, MBA, FACP, medical director, WGH Hospital Medicine, LaGrange, Ga.
Reference
Karen Appold’s cover story, “Copper,” in the September 2013 issue, offers an exciting and encouraging development in the struggle to prevent hospital-acquired infections, but I have two concerns. As copper tarnishes, it forms a surface patina of copper hydroxide and copper carbonate. Would this patina act as a physical barrier, preventing bacteria from coming into contact with elemental copper and inhibiting the antimicrobial effect? If so, the obvious solution is to polish the surface frequently enough to prevent tarnishing.
The second concern regards the use of copper-nickel alloys. Many people are sensitive to nickel, [with reactions that] usually manifest as contact dermatitis. A study by the North American Contact Dermatitis Group (NACDG), conducted between 1992-2004 and involving 25,626 patients who were patch-tested, showed a prevalence of nickel sensitivity of 18.8% in 2004, increased from 14.5% in 1992.1
With a current U.S. population of approximately 317 million, a prevalence of 18.8% would mean nearly 60 million people with nickel sensitivity. Extrapolating from the NACDG study, the rate is probably actually higher. Medical devices made with copper-nickel alloys that contact the patient’s skin would cause contact dermatitis, and implanted devices would have the potential for more severe allergic reactions.
I simply urge foresight and caution in the use of various copper alloys for medical applications.
Rod Duraski, MD, MBA, FACP, medical director, WGH Hospital Medicine, LaGrange, Ga.