People with existing nickel allergies are at risk for rashes from nickel-containing devices. According to an advisory about cellphones on the website of the Nickel Institute, a global association based in Toronto representing nickel producers, the risk arises from contact with nickel-plated outer surfaces "over prolonged periods of time."
"The length of time required to elicit an allergic reaction will vary from 5 or 10 minutes to never, depending on the sensitivity of the individual," the advisory says.
Nickel rashes also have been traced to other common products including some jewelry, eyeglass frames and zippers.
Jacob said evidence suggests nickel allergies are become more common, or increasingly recognized. She cited national data showing that about 25 percent of children who get skin tests for allergies have nickel allergies, versus about 17 percent a decade ago.
Clare Richardson, spokeswoman for the Nickel Institute, said research shows as many as 17 percent of women and 3 percent of men in the general population have nickel allergies. She noted that the European Union has legislation aimed at limiting the amount of nickel that can be released from products that come in direct and prolonged contact with skin.
AP Medical Writer Lindsey Tanner can be reached at http://www.twitter.com/LindseyTanner