Nickel: a unique allergen – from molecular structure to European legislation

Abstract

Nickel is a unique, mysterious and troublesome chemical element. Its molecular structure (unfilled electron shell) determines the high-reactivity and multidirectional biological effects. Some authors classify nickel as trace element, although its biological role in animal and human metabolism remains unclear. Conversely, nickel possesses strong sensitizing potential: as many as 65 million Europeans may be allergic to nickel. In this article, we review chemical and biological properties of nickel, pathomechanism, clinical symptoms and diagnosis of contact allergy to nickel, epidemiology and risk factors. Finally, public health measures and legal regulations of the EU aimed at protecting the population from nickel allergy are discussed, with particular attention devoted to the ‘Nickel Directive’ 94/27/EC.

Keywords::

• biological effect
• contact allergy
• immunotoxicity
• legal regulation
• nickel
• Nickel Directive
• prevention
• risk factor

Financial & competing interests disclosure

This article was prepared as a part of the European Commission’s Marie Curie Reintegration Grant MERG-6-CT-2005–014813 to Radoslaw Spiewak, and of the statutory research project 501/P/12/WOZ of the Jagiellonian University Medical College, Krakow, Poland. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Notes

From [79].