Suitable test concentration of cobalt and concomitant reactivity to nickel and chromium. A multicentre study from the Swedish Contact Dermatitis Research Group
Background: In Sweden, cobalt chloride 0.5% has been included in the baseline series since the mid-1980s. A recent study from Stockholm showed that cobalt chloride 1% petrolatum (pet.) was more suitable than 0.5%. Cobalt chloride at 1.0% has been patch tested for decades in many European countries and around the world. Objectives: To study the suitability of patch testing to cobalt 1.0% vs 0.5% an