Oral nickel exposure may induce Type I hypersensitivity reaction in nickel-sensitized subjects.

Abstract Background Little is known about the clinical and immunological changes in the nickel allergic patients with systemic symptoms. We aimed to evaluate T helper cell responses of patients with different clinical presentations due to nickel. Methods Patients having various allergic symptoms and positive patch test results to nickel and 20 controls underwent skin prick tests with nickel. IL-10, IL-4, IL-5 and IFN-gamma were measured in the culture supernatants of PBMC stimulated by nickel during lymphocyte proliferation test (LTT). Results 69 patients (56 female, mean age: 49.2 ± 13.1), 97% having nickel containing dental devices and 20 controls (8 female, mean age 34.9 ± 12.06) were evaluated. Skin prick tests with nickel were positive in 70% of the patients (p  Conclusion This study suggests the presence of Type I hypersensitivity in addition to a Type IV immune reaction in patients with chronic systemic symptoms related to nickel. Nickel containing dental alloys and oral nickel intake seem to trigger systemic symptoms in previously nickel sensitized patients.