Diet in the Management of Nickel Allergy

Nickel is regarded as one of the most common causes of allergic contact dermatitis, an intensely itchy rash in response to prolonged and repeated contact with nickel in individuals who have a sensitivity to it. Prior estimates have suggested that a little over 1 million children in the United States had some sort of sensitization or allergy to nickel.

Items that may contain nickel include jewelry, metallic fasteners or snaps on clothing, belt buckles and metal hinges on eyeglasses, in addition to other consumer products and household items, such as metal utensils or tools. However, it's not simply a matter of an item containing nickel which can influence allergic contact dermatitis. It's actually the amount of nickel that is released, which is an important consideration for items that will be in contact with the skin for an extended amount of time or repeatedly.

While nickel has been a suspect of contact dermatitis since the 19th century, recent studies have begun to look at an increased range of possible side effects of systemic nickel from dietary intake, dental fillings and medical implants. Questions have been raised about gastrointestinal symptoms and a potential role in inflammatory conditions, such as irritable bowel syndrome, ulcerative colitis and celiac disease.

Available studies focused on these conditions in relation to nickel are still limited at this time. One very small pilot study examined the prevalence of nickel allergic contact mucositis in females who were diagnosed with celiac disease, yet continued to experience symptoms while adhering to a gluten-free diet. The authors noted that many foods promoted on a gluten-free diet also have a high nickel content, along with some crossover between high-nickel foods and high-FODMAP foods. All 20 participants tested positive for nickel allergic contact mucositis and were assigned a low-nickel diet (in addition to a gluten-free diet) for a duration of three months. At the end of the trial, improvement in 20 out of 24 symptoms were reported and close to half were considered statistically significant.

One of several limitations indicated by the authors was the lack of standardized measurements for determining nickel content in foods. Several studies referenced grains, nuts, legumes and chocolate to be among the highest sources. However, the level of nickel in foods varies depending on the soil used to grow the plant and the source of water in the case of seafood.

In addition to nickel naturally present in foods, any processing of foods may increase its nickel content. For example, the metal grinders used in grain mills may increase the nickel content of flour. The use of stainless-steel, which makes up two-thirds of global nickel production, also may transfer nickel into foods when cooking with pans or utensils made from it.

Only a small amount of the nickel in food is absorbed, but individuals who are deficient in iron may be at risk of absorbing increased amounts. However, research has shown that the same system is used by the body to transport both these minerals across the intestinal mucosa. So, when iron is transported, nickel is not. In addition to limiting high-nickel foods, by including iron-rich foods, nickel absorption should be limited. What's more, because a trace amount of nickel is present in almost all food, a nickel-free diet is not possible.

While recommendations for adults with nickel allergy may include managing symptoms by foregoing high-nickel sources, a low-nickel diet is not currently recommended for children. Limited studies in this population, concerns for inadequate intake and risk of malnutrition have been noted by the AAP.

References:

• American Academy of Dermatology. Position statement on nickel sensitivity. August 22, 2015. Accessed June 29, 2022.
• Silverberg NB, Pelletier JL, Jacob SE, Schneider LC; SECTION ON DERMATOLOGY, SECTION ON ALLERGY AND IMMUNOLOGY. Nickel Allergic Contact Dermatitis: Identification, Treatment, and Prevention. Pediatrics. 2020;145(5).
• Ahlström MG, Thyssen JP, Wennervaldt M, Menné T, Johansen JD. Nickel allergy and allergic contact dermatitis: A clinical review of immunology, epidemiology, exposure, and treatment. Contact Dermatitis. 2019;81(4):227-241.
• Borghini R, De Amicis N, Bella A, Greco N, Donato G, Picarelli A. Beneficial Effects of a Low-Nickel Diet on Relapsing IBS-Like and Extraintestinal Symptoms of Celiac Patients during a Proper Gluten-Free Diet: Nickel Allergic Contact Mucositis in Suspected Non-Responsive Celiac Disease. Nutrients. 2020 Jul 29;12(8):2277.
• Joneja, J.V. Chapter 22: Nickel Allergy. In: The Health Professionals Guide to Food Allergies and Intolerances. Chicago, IL: Academy of Nutrition and Dietetics; 2012:215-222.