Allergy to complex platinum salts: A historical prospective cohort study

Abstract

Objective: To assess the incidence of allergy to complex platinum salts in a platinum refinery.

Methods: A historical prospective cohort study was carried out on 77 workers (67 men) who started work between 1 January 1979 and 31 December 1991 and who were not atopic on skin prick tests to three common allergens at the time of recruitment. Skin prick tests with complex platinum salts were carried out and diagnosis of allergy to complex platinum salts made by the company's doctor. Skin tests and medical examinations were carried out routinely every six months. Follow up was until 30 September 1992 or until leaving refinery work.

Results: 18 workers developed a positive result on skin tests and 23 developed symptoms, including all 18 subjects with positive skin tests; the probability of surviving (95% confidence interval (95% CI)) for 72 months after joining the company, with negative skin test results was 0.67 (0.51-0.79) or with no symptoms was 0.63 (0.49-0.75). The incidence of positive skin tests and symptoms was highest during the first two years of work. Symptoms occurred more frequently in September and October than during the other months of the year. The exclusion of atopic subjects did not seem to have resulted in a lower incidence of sensitisation. Smoking was a significant predictive factor for both positive skin tests (estimated relative risk 5.53) and symptoms (4.70).

Conclusion: The findings confirm that smoking is and that atopy may not be a high risk factor for the development of allergy to complex platinum salts. The high incidence of sensitisation and the available data on the clinical course of sensitised workers show that sensitised workers must be promptly and completely removed from exposure.