Background: This is the first randomized, double-blind, placebo-controlled trial (EUDRACT No. 2009-013923-43) evaluating nickel oral hyposensitizing treatment (NiOHT) in patients with "systemic nickel allergy syndrome" (SNAS), characterized by Ni-allergic contact dermatitis and systemic reactions after eating Ni-rich food.
Methods: Adults with positive Ni-patch test, who reported symptoms suggesting SNAS, which improved after Ni-poor diet, and were positive to Ni-oral challenge were eligible.