Nickel-induced hypersensitivity: etiology, immune reactions, prevention and therapy.

As a contact allergen causing type I and type IV hypersensitivity, mediated by reagins and allergen-specific T lymphocytes, expressed in a wide range of cutaneous eruptions following dermal or systemic exposure, nickel has acquired the distinction of being among the most frequent causes of hypersensitivity, occupationally as well as among the general population. In synoptic form the many effects that nickel has on the organism are presented, to provide a comprehensive picture of the aspects of that metal with many biologically noxious, but metallurgically indispensable characteristics. This paper reviews the epidemiology, the prognosis for occupational and non-occupational nickel allergic hypersensitivity (NAH), the many types of exposure and the resulting immune responses, immunotoxicity and rate of diffusion through the skin. Alternatives towards prevention and remediation, topical and systemic, for this pervasive and increasing form of morbidity resulting from multiple types of exposure are discussed. Merits and limitations of preventive measures in industry and private life are considered, as well as the effectiveness of topical and systemic therapy in treating NAH.