BACKGROUND: In the last decades, palladium is widely used in dentistry. Allergic reactions to palladium are rarely diagnosed with patch testing, even when positive results would be expected. Palladium tends to cross-react with nickel, which should give rise to more positive reactions to palladium dichloride (standard test salt). OBJECTIVE: The aim of the study was to test whether or not mono-nuclear sodium tetrachloropalladate (Na(2)[PdCl(4)]) in petrolatum is a better test salt for diagnosing palladium allergy. Positive reactions to the investigated test salt are compared not only with PdCl(2(aq.)), but also to NiSO(4(aq.)) and NiSO(4(pet.)). PATIENTS/ METHODS: Concentration series of Na(2)[PdCl(4)] were carried out. 164 consecutive patients were patch tested. RESULTS: 3% of Na(2)[PdCl(4)]((pet.)) was found to be the highest non-irritative concentration. The results show (n = 164) that Na(2)[PdCl(4)] covers all reactions to PdCl(2) (1.8%) and provokes more positive reactions (14%). From the 164 patients, 18.3% reacted positively to at least 1 of the nickel salts. CONCLUSION: The sensitivity of patch testing with Na(2)[PdCl(4)] is increased compared with the PdCl(2) salt. Therefore, it can be concluded that Na(2)[PdCl(4)] is to be a better test salt for diagnosing palladium allergy with patch testing.
BACKGROUND: In the last decades, palladium is widely used in dentistry. Allergic reactions to palladium are rarely diagnosed with patch testing, even when positive results would be expected. Palladium tends to cross-react with nickel, which should give rise to more positive reactions to palladium dichloride (standard test salt). OBJECTIVE: The aim of the study was to test whether or not mono-nuclear sodium tetrachloropalladate (Na(2)[PdCl(4)]) in petrolatum is a better test salt for diagnosing palladiumallergy. Positive reactions to the investigated test salt are compared not only with PdCl(2(aq.)), but also to NiSO(4(aq.)) and NiSO(4(pet.)). PATIENTS/ METHODS: Concentration series of Na(2)[PdCl(4)] were carried out. 164 consecutive patients were patch tested. RESULTS: 3% of Na(2)[PdCl(4)]((pet.)) was found to be the highest non-irritative concentration. The results show (n = 164) that Na(2)[PdCl(4)] covers all reactions to PdCl(2) (1.8%) and provokes more positive reactions (14%). From the 164 patients, 18.3% reacted positively to at least 1 of the nickel salts. CONCLUSION: The sensitivity of patch testing with Na(2)[PdCl(4)] is increased compared with the PdCl(2) salt. Therefore, it can be concluded that Na(2)[PdCl(4)] is to be a better test salt for diagnosing palladiumallergy with patch testing.