Cr(III) and Cr(VI) in leather and elicitation of eczema.

The aim of the present study was to investigate the relation between the content of Cr(VI) and soluble Cr(III) in leather and the ability of the leather to elicit eczema in chromium allergic patients. An array of chromium-tanned leather samples was analysed for the content of total Cr(VI) and soluble Cr(III) using the DIN 53314 and the DS/EN 420 methods. Subsequently, a group of 15 patients with a history of foot eczema and leather exposure was exposed to a selection of 14 chromium- and 1 vegetable-tanned leather sample on the upper back for 48 hr. In addition, one leather sample was used for a prolonged 14-day exposure study. In total, 4 of the 15 patients reacted to at least one leather sample, and 5 of the 14 leather samples elicited a reaction in at least 1 patient. The prolonged exposure study demonstrated that an extended exposure period may reveal allergenic potential of a leather sample not otherwise identified using an ordinary 48-hr exposure period. No relation was observed between the measured content of Cr(VI) and soluble Cr(III) in the leather and the elicitation of eczema. Thus, in order to evaluate the quality of chromium-tanned leather in relation to preventing allergic skin reactions, other more clinical relevant methods reflecting the actual bioavailable Cr(III) and Cr(VI) fractions should be developed.