Sensitization to palladium chloride: a 10-year evaluation.

BACKGROUND: Palladium is increasingly used in industry, jewelry, and dentistry and is becoming more common since the European directive restricting the use of nickel in all products placed in direct and prolonged contact with the skin. OBJECTIVE: The role of palladium sensitization is still unclear, and the aim of our study is to evaluate the trend of sensitization in a contact dermatitis clinic population during a 10-year period. METHODS: We report our experience with 4,446 patients (3,077 female, 1,369 male; mean age, 40.1 +/-13.7 years) with suspected contact dermatitis patch-tested during the period of 1991 to 2000. RESULTS: A positive patch-test result to palladium chloride 1% was indicated in 236 patients (5.3%), with a higher percentage in females (6.7%) than in males (2.3%), and the sensitization to this metal has increased over the specified period, to a maximum in the year 2000 (9.7%). In the majority of cases, subjects were polysensitized (92.8%), but 7.2% of subjects were patch-test positive only to palladium. Of palladium-sensitized patients, 40.5% complained of hand dermatitis, 47.4% complained of body dermatitis, and 1.7% complained of burning mouth syndrome. Palladium sensitization is significantly related to female sex (OR = 3.08; 95% CI, 2.07-4.61) and to sensitization to other metals, with a maximum for nickel sulfate (OR = 32.9; 95% CI, 21.3-51.5). CONCLUSION: Sensitization to palladium is increasing by the year, reaching high values, but its role in reducing sensitization and symptoms is still unclear because of the frequent cosensitization with nickel and the low number of monosensitized patients with relevant sensitizations. We need to follow palladium sensitization in future years to verify an increase of sensitization due to the increasing use of this metal.