Prevention of nickel allergy by regulation of specific exposures.

Nickel allergy is a cell-mediated immune response. Most cases of nickel allergy can be related to skin contact with nickel containing metallic items as buttons, suspenders, ear-ornaments etc. Epidemiological studies have shown a sensitization frequency of 20 percent in young females and 10 percent in the elderly. Two to four percent of males are sensitized. The biological significant parameter is not the nickel concentration in the alloy or coating but the amount released to the skin during exposure to human sweat. A threshold of 0.5 microgram/cm2/week has been established, where only a minor part of the nickel sensitive will react. A legislation limiting nickel exposure from specific consumer items is in force in Denmark. An expanded exposure regulation was adopted, but not yet implemented, by the EU-countries in 1994.