BACKGROUND: Positive patch tests to copper sulfate are regularly observed, although copper is reported as a rare allergen with a low sensitizing potential. Usually they are claimed to be irritant and unspecific. OBJECTIVE: The aim of this study was to assess the relevance and the diagnostic value of positive reactions to copper. METHODS: A total of 2660 routine patch tests were analyzed for positive reactions to copper and other metal allergens: copper, 3.53%; nickel, 21.02%; palladium, 5.90%; cobalt, 3.31%. RESULTS: Reactions to copper and nickel were highly significantly associated with each other. Twenty-six patients with a positive routine test to copper were retested. The reproducibility was modest (38%), but again significantly associated with nickel sensitization. CONCLUSION: These clinical data support a copper-nickel cross-reactivity concept on T-cell level based on recently published molecular data. We conclude that positive patch tests to copper are mostly specific; however, they are usually of low clinical relevance.
BACKGROUND: Positive patch tests to copper sulfate are regularly observed, although copper is reported as a rare allergen with a low sensitizing potential. Usually they are claimed to be irritant and unspecific. OBJECTIVE: The aim of this study was to assess the relevance and the diagnostic value of positive reactions to copper. METHODS: A total of 2660 routine patch tests were analyzed for positive reactions to copper and other metal allergens: copper, 3.53%; nickel, 21.02%; palladium, 5.90%; cobalt, 3.31%. RESULTS: Reactions to copper and nickel were highly significantly associated with each other. Twenty-six patients with a positive routine test to copper were retested. The reproducibility was modest (38%), but again significantly associated with nickel sensitization. CONCLUSION: These clinical data support a copper-nickel cross-reactivity concept on T-cell level based on recently published molecular data. We conclude that positive patch tests to copper are mostly specific; however, they are usually of low clinical relevance.
Authors: Michele Gusberti; Urs Klemm; Matthias S Meier; Monika Maurhofer; Isabel Hunger-Glaser Journal: Int J Environ Res Public Health Date: 2015-09-11 Impact factor: 3.390