Nickel oral hyposensitization in patients with systemic nickel allergy syndrome

Background: This is the fi rst 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 Niallergic 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. Patients were randomly assigned to three treatments (1.5 g, 0.3 g, or 30 ng Ni/week) or placebo for a year, with progressive reintroduction of Ni-rich foods form the 5 th month. Out of 141 patients randomized, 113 completed the trial. Endpoints were effi cacy and tolerability of treatment. Results: During Ni-rich food re-introduction, the 1.5 g Ni/week group had a mean VAS score signifi cantly higher than placebo (p 0.044), with signifi cant improvement of gastrointestinal symptoms (p 0.016;) and signifi cantly fewer rescue medications. Cutaneous manifestations also improved but without reaching statistical signifi cance. After the treatment, oral challenge with higher Ni doses than at baseline were needed to cause symptoms to fl are-up in signifi cantly more patients given 1.5 g Ni/week than placebo (p 0.05). Patients reported no side-eff ects. Conclusions: NiOHT is eff ective in SNAS, in particular on gastrointestinal manifestations, with trend toward improvement of cutaneous symptoms.