In a much-cited study, Lantinga et al. (7) patch tested 141 individuals who had eczema with potassium dichromate 0.5%, nickel sulfate 5%, cobalt chloride 1%, thiuram mix 1%, p-phenylenediamine (PPD) mix 0.6%, epoxy resin 1% and balsam of Peru 25%. A greater percentage of women than men reacted to nickel sulfate and potassium dichromate.