Positive patch-test reactions to platinum are rare.

Although contact allergy to some metals is common, patch testing for allergy to platinum is rarely performed. To determine the prevalence of positive patch-test reactions to platinum in an unselected consecutive group of patients presenting for diagnostic patch testing. Unselected patients who presented with a possible diagnosis of contact dermatitis were tested with a series of allergens, including ammonium tetrachloroplatinate 0.25% aqueous. Of 446 patients tested, only 2 females showed positive reactions to platinum; one had no other positive reactions, and the other had reactions to other metals. Positive patch-test reactions to platinum are rare. However, platinum jewelry may occasionally provoke allergic contact dermatitis.