Platinum in the environment: frequency of reactions to platinum-group elements in patients with dermatitis and urticaria

The aim of the present paper is to evaluate whether increasing environmenta l exposure increases the frequency of the positive prick and patch test rea ctions to certain chlorinated platinum salts in patients with dermatitis an d urticaria. 800 consecutive subjects with contact dermatitis (n=749) and u rticaria (n=51) were variously patch and prick tested with 30 haptens of a standard series, with aqueous solutions of, respectively, hexachloroplatini c acid (H-2[PtCl6]), potassium tetrachloro-platinate (K-2[PtCl4]), sodium h exachloroplatinate (Na-2[PtCl6]), iridium chloride (IrCl3), rhodium chlorid e (RhCl3) and palladium chloride (PdCl2), and with 16 common inhalants. 153 workers, variably exposed in a platinum refinery, were patch and prick tes ted only with solutions containing platinum-group elements at various conce ntrations and with 16 common inhalants. Platinum-group elements did not eli cit positive patch or prick test reactions in non-occupationally exposed su bjects. In contrast, in exposed workers, positive patch test reactions at d ay 2 and at 25 min, respectively, were found in 2 subjects with hand dermat itis and in 2 with urticaria and asthma. 22 out of the 153 workers, 18 of w hom had rhinitis, asthma, and urticaria, gave positive prick test reactions to 1 or more salts. Furthermore, on patch and prick testing, 4 cross-react ions between platinum, palladium, iridium and rhodium were demonstrated. In conclusion, the test results demonstrate that the present concentration in the environment does not increase the incidence of reactions to platinum s alts in patients with dermatitis and/or urticaria. However, if the average level of environmental platinum exposure approaches those existing in indus trial settings in the future, we are going to observe more frequent health effects.