MERCURY ALLERGY IN A CONTACT-DERMATITIS CLINIC IN NORTHERN-IRELAND

441 consecutive patients (294 female, 147 male) with suspected contact dermatitis were patch tested to the European standard series, mercury metal (1% pet.), ammoniated mercury (1% pet.), and mercuric chloride (0.1% aq.). 14 patients (3.2%), 12 of whom were female, showed a posit ive response to 1 or more mercury compounds; none reacted to mercuric chloride alone. Primary sensitization was most likely due to either in oculation with vaccines containing merthiolate preservatives or amalga m dental restorations. Mercury allergy was of historical clinical rele vance in only 2 patients, both women who developed gingivostomatitis f ollowing insertion of amalgam dental fillings. 1 of these women subseq uently developed allergic contact dermatitis from contact lens solutio ns, shampoos and cosmetics which contained mercury preservatives. On t he basis of these findings, we recommend patch testing with both metal lic mercury and ammoniated mercury in patients with suspected mercury allergy.