[Cutaneous sensitivity to mercury and its compounds].

We present the results of a study, spread over a 12-year period, concerning the frequency of skin sensitization to mercury and some of its compounds in a Spanish community. Among 2,592 subjects suspected of allergic contact dermatitis, 3.5 p. 100 had a positive test to metallic mercury 0.5 p. 100 in petroleum jelly. The pertinence of the test was regarded as "present" or "fast" in 63.9 p. 100 of the cases, and the dermatitis was found to be related to antiseptic Mercurochrome (merbromin) solutions, cosmetics containing ammoniated mercury and inhalation of mercury after breaking of thermometers. We consider that in children metallic mercury should be tested at a concentration not exceeding 0.1 p. 100. Among 2,154 subjects suspected of allergic contact dermatitis, 109 (5 p. 100) had a positive test to thiomersal 0.1 p. 100 in petroleum jelly. The pertinence of the test was regarded as "present" or "past" in 53.8 p. 100 of the cases, and the dermatitis was attributed to antiseptic solutions, eye drops, cosmetics and shoes. There was no cross-reaction between thiomersal and mercury, except in those cases where mercury chloride was the allergic determinant responsible for sensitization to thiomersal (39.4 p. 100 of the cases). Fifteen patients consulted for photoallergy to piroxicam, and all had a positive test to thiosalicylic acid which is the compound most frequently responsible for sensitization to thiomersal (51.6 p. 100 of our cases) and for cross-reaction between thiomersal and piroxicam.