A retrospective investigation of hexavalent chromium allergy in southern Sweden.

Background: Historically, allergic contact dermatitis caused by hexavalent chromium [Cr(VI)] in cement was the most common cause of invalidity attributable to skin disease in Sweden. Since the legislation to reduce Cr(VI) in cement was introduced in 1989, we rarely see allergic contact dermatitis caused by cement.

Objectives: To examine the frequency of contact allergy to Cr(VI) in southern Sweden in 2005-2014.

Methods: We investigated the occurrence of positive reactions to potassium dichromate 0.5% pet. in consecutively tested dermatitis patients, and compared the occurrence of atopic dermatitis, localization of dermatitis and simultaneous positive reactions to cobalt chloride and nickel sulfate in the Cr(VI)-positive patients with those in a group of patients with a similar age and sex distribution.

Results: In total, 6482 patients were tested, and 233 Cr(VI)-allergic individuals were found (3.6%). A significantly higher proportion of atopic dermatitis was found among Cr(VI)-allergic patients, and a significantly higher share of foot dermatitis was found among Cr(VI)-allergic women, than among controls. Cr(VI) allergy was less likely when both nickel allergy and cobalt allergy were present.

Conclusion: A relatively high frequency of contact allergy to Cr(VI) was found. The cause has shifted from cement exposure to other exposures, probably mainly leather.