[Copper sulfate allergy with special reference to internal exposure]

Sensitization due to copper has rarely been reported, so far. There is no standard patch test regarding allergy against copper sulphate (CSA). Our study is concerned with the evaluation of data of 10.936 patients patch tested between 1975 and 1985. Since--aside from external exposure--internal exposure to copper sulphate has become increasingly significant, we additionally tested 118 female patients who were or had been wearing intrauterine contraceptives containing copper. Our results showed that CSA is relatively rare and not as often found as sensitization to cobalt or nickel. CSA is rarely monovalent, but usually associated with other metal allergies, especially with nickel and cobalt sensitization. Since we frequently saw toxic reactions to copper sulphate, the skin tests should be performed with 0.5 or 0.01% copper sulphate in water. The test persons with intrauterine contraceptives were not often sensitive either; thus the likelihood of CSA seems to be small in these cases. Individual patients, however, may develop skin eruptions caused by an intrauterine contraceptive containing copper sulphate, as we can prove in one of our patients.