Allergic contact dermatitis caused by cobalt in leather - clinical cases.

In 2013, we raised suspicion that cobalt in leather could be responsible for hitherto unrecognized cases of allergic contact dermatitis. We saw a patient sensitized only to cobalt with clear long-term exposure to cobalt from a leather sofa, and observed resolution of dermatitis following avoidance (1). In 2014,we performed a questionnaire study, which showed a positive and significant association between cobalt allergy and a history of dermatitis caused by non-occupational exposure to leather articles (2). Recently, we published an article showing high amounts of cobalt in selected leather swatches from furniture (3). Here, we report 2 additional cases of allergic cobalt dermatitis caused by consumer leather exposure, to increase awareness about this topic.