LOS ANGELES (KABC) -- Experts estimate nearly 20 percent of people in the U.S. are allergic to nickel, and doctors are saying there may be a high tech cause behind the reactions.
Dermatologist Dr. Laura Ferris said she sees the allergy often.
"Traditionally, we've seen nickel allergies in places like earrings or from belt buckles, but now we're tending to see a lot more on the wrist from fitness trackers," she said.
One popular model was recalled after thousands complained of skin irritation, which was later linked in part to nickel in the casing.
Now some companies are giving users a heads up, explaining that some contain "traces of nickel" and "some people may experience allergies."
But it's not just fitness devices. The American Academy of Dermatology warns that some electronic devices, including cellphones, laptops and tablets, may contain nickel.
"People who are real sensitive will break out from exposure to even stainless steel because the amount of nickel it releases is enough to show a reaction or rash," Dr. Lawrence F. Eichenfield said.
Some people may even be allergic to the traces of nickel that can be found in certain foods. Experts advise that if a person is extremely sensitive to nickel, they should avoid the following foods: soybean, tofu, licorice, buckwheat, coco powder, clams, cashews and figs.
The person should also put a cover on their phone if they get reactions from electronics. Some manufacturers said they're working closely with dermatologists to make sure products are less likely to cause reactions.