Study Unlocks Mystery of Nickel Allergy

Discovery of How Nickel Causes an Allergic Reaction Could Lead to New Treatments

Medically Reviewed by Laura J. Martin, MD on August 16, 2010

Aug. 16, 2010 -- Scientists in Germany have found the biological mechanisms behind nickel allergy, a common cause of contact allergic dermatitis that causes itching, burning, and redness.

Researchers used mice to show how nickel induces an immune system response. Nickel binds to a protein called toll-like receptor 4 or TLR4, which signals the immune system to initiate an inflammatory response.

TLR4, the researchers report, could potentially serve as a molecular target for blocking an allergic reaction to nickel. Their findings are reported in this week's issue of Nature Immunology.

The researchers found that nickel binds to two specific sites on TLR4, triggering a reaction. Intervening in this process, such as disabling TLR4 to recognize nickel and react while maintaining its innate ability to detect pathogens, could help reduce nickel allergy symptoms.

"Future strategies for prophylaxis and treatment of contact allergy to nickel may no longer need to rely on currently used topical immunosuppressants," the researchers write.

Nickel is a metal found in everything from jewelry to zippers to cell phones. Recently, the Canadian Medical Association advised consumers to be aware of nickel exposure through both cell phone cases and cell phone batteries. A 2008 study published by the Canadian Medical Association Journal found that nearly half of the cell phones they tested contained some free nickel.

According to the researchers, about 65 million people in Europe have nickel allergy. In the U.S., nickel allergy is particularly high among females aged 18 and younger.

Europe introduced regulations to decrease the prevalence of nickel allergy, but nickel allergy is increasing across North America.

Show Sources


Schmidt, M. Nature Immunology, published online Aug. 15, 2010.

Lu, L. Dermatologic Clinics, April 2009; vol 27: pp 155-161.

Canadian Medical Association Journal, Jan. 1, 2008.

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