Chelating effect of EDTA on nickel.

The chelating effect of disodium ethylenediamine tetra-acetate (EDTA) in nickel-allergic patients was investigated. After pretreatment of the right half of the patient's back with 10% EDTA in a cream, and the left half of the back with the cream base only, various concentrations of nickel sulphate were patch tested on these areas. The blocking effect of the 10% EDTA cream appeared to be significant in comparison with that of the cream base only (p less than 0.01). A barrier cream with 10% EDTA might be of help in nickel-allergic patients with eczema of the hands.