Association between cobalt allergy and dermatitis caused by leather articles – a questionnaire study

Abstract

Our study suggests a positive association between cobalt allergy and a history of dermatitis caused by non-occupational exposure to leather articles.

Causative exposures and temporal development of cobalt allergy in Denmark between 2002 and 2017

“…The latter correlation between cobalt and shoes is supported by the significant association between foot eczema and cobalt allergy in our study (aOR 2.1, 95%CI: 1.6‐2.9). Similarly, in a case‐control study from Denmark including 126 cobalt‐allergic patients without concomitant hexavalent chromium allergy, a significant association was shown between current foot eczema, presumably caused by leather shoes, and cobalt allergy (aOR 1.9, 95%CI:1.1‐3.3) . Collectively, these data show that cobalt from leather causes allergic cobalt dermatitis, and that leather exposure should be evaluated in patients with cobalt allergy.…”

“…We have observed single cases of allergic cobalt dermatitis caused by leather items, but suspect that leather might be a more important source of cobalt exposure than hitherto realized. In this respect, a recent questionnaire case‐control study from our clinic showed that leather was the most frequently reported exposure source causing dermatitis in patients with cobalt allergy without concomitant allergy to hexavalent chromium …”

Contact Sensitization in Children: A Retrospective Study of 2,614 Children from a Single Center

“…Of 291 patients with a positive patch test to cobalt, 135 (46.4%) also had a positive reaction to nickel, confirming that contact sensitization to cobalt is often but not always associated with contact sensitization to nickel and challenging the traditional view of cobalt as a concomitant allergen . Contact sensitization to cobalt in children may result not only from jewelry, but also from toys and leather footwear , as underlined by the association with foot dermatitis.…”

A retrospective investigation of hexavalent chromium allergy in southern Sweden

“…Simultaneous positive patch test reactions to potassium dichromate, nickel sulfate and cobalt chloride are often reported (17,18). These concurrent reactions are most often explained by multiple sensitization rather than cross-reactivity, and the association between cobalt and Cr(VI) allergy has been attributed to the presence of both metals in both leather and cement (17,18).…”