Consumers are mainly exposed to palladium from jewellery and dental restorations. Palladium contact allergy is nearly always seen together with nickel allergy, as palladium and nickel tend to cross-react. We aimed to analyse the available palladium patch test data and case reports to determine whether the prevalence of palladium mono-sensitization has increased. Based on available patch test data from the period 1986-2008, a total of 10 778 patients were patch tested with palladium chloride. The median prevalence of palladium allergy was 7.8% (range