The prevention of nickel contact dermatitis. A review of the use of binding agents and barrier creams.

Chelating agents and other substances can be used to bind nickel or reduce its penetration through the skin, and hence to reduce the symptoms in subjects with nickel sensitivity. Topical usage is mostly described but, in some studies, chelating agents have been given systemically. The most effective ligand for nickel so far described is 5-chloro-7-iodoquinolin-8-ol. Although normally regarded as safe, its usage in some situations may be limited by concerns about its toxicity. Other ligands with demonstrable effect include ethylenediaminetetraacetic acid in various forms, diphenylglyoxime and dimethylglyoxime. Cation exchange resins can effectively bind nickel and work both in vitro and in vivo. Propylene glycol, petrolatum and lanolin reduce the absorption of nickel through the skin. Corticosteroids and cyclosporin work in nickel dermatitis by suppressing the immunological reaction rather than through an effect on nickel. Studies of the oral administration of ligands such as tetraethylthiuram disulphide have given conflicting results but the use of these agents is limited by hepatoxicity in any case. Some compounds offer potential for use in the prophylaxis of nickel dermatitis. Further work is required to develop the existing agents and to look at the use of novel combinations, such as that of a cation exchanger with a ligand.