We may not think that we have much contact with nickel on a regular basis, but it often is mixed with other metals to create alloys that are used in common items. Constant contact with these items can cause an allergic reaction in nickel-sensitive people that results in a skin rash, or “allergic contact dermatitis.” Nickel is the most common metal associated with this condition, though people can have allergies to other metals as well.
With allergic contact dermatitis there is a sensitization period, and can range from days to months. The sensitization period is the time between initial exposure to the allergen and when the body becomes hyper-sensitized. During this time there is no outer rash or reaction on the skin, but, the allergens are activating immune cells within the body. The next time the person is exposed to the metal after the sensitizing period will result in a skin reaction which can appear 12 to 48 hours later. Avoiding contact with the metal will resolve the rash typically within two weeks.
Which common items contain nickel?
Aside from the familiar coin, nickel is present in many everyday items--and some not-so-everyday items--including jewelry, belt buckles, clothing snaps and zippers, hairpins, kitchen utensils, tattoo ink, dental fillings, artificial body implants (such as joint replacements and stents), eyeglasses and cell phones.
So it’s not easy to avoid exposure to nickel. But there are steps you can take, such as limiting jewelry purchases to items with stainless steel or hypo-allergenic metal. Some jewelry firms do carry lines without nickel. And, of course, more expensive jewelry, such as silver, gold, platinum and other pure metals will not contain nickel.
For health-related items avoiding nickel is not so easy. A recent study published in Circulation: Cardiovascular Interventions looked at how people with a nickel allergy reacted to stents, and whether that increased risk for restenosis, heart attack or death. Fortunately, researchers found that nickel in stents did not increase the frequency of allergic responses. Though more research is necessary, this study does suggest that stents are safe for patients with a nickel allergy.
Are there any regulations for nickel use?
Although the U.S. currently has no regulations regarding nickel, several European countries have had rules in place regulating its use since the early 1990s. In response to rising nickel allergies in Western Europe, Denmark, for instance, began regulating nickel in consumer products such as jewelry in 1990. A 2009 study published in the New England Journal of Medicine looked at the prevalence of nickel allergy in Denmark prior to the regulation, and then again after to see if there was a decrease. Researchers found that, although it was impossible to assign direct cause and effect, the prevalence of nickel allergy did decrease after the regulations went into effect.