Systemic Nickel Allergy Syndrome: Epidemiological Data from Four Italian Allergy Units

Abstract

The prevalence of nickel hyper-sensitivity varies widely in different countries, nevertheless it is the leading cause of contact dermatitis. The presence of nickel in the diet (mainly plant foods) in some nickel-sensitive subjects can provoke/aggravate eczema and systemic contact dermatitis as well as cause extra-cutaneous symptoms (respiratory, gastrointestinal, neurological). These symptoms, correlated to the ingestion of nickel-containing foods and beverages, in nickel patch test positive individuals, defines the so called “systemic nickel allergy syndrome (SNAS)”, a condition successfully treated by oral desensitization. Although numerous studies have investigated the prevalence of contact nickel allergy or addressed the relationship between nickel intake and onset of systemic symptoms, to our knowledge no epidemiological studies have attempted to estimate the prevalence of SNAS. Therefore, we decided to evaluate consecutive patients (1,696), afferent to four allergy units in Sicily, a region of southern Italy, from October 2010 to March 2011. SNAS was confirmed in 98 patients (5.78%) of the 1,696 studied, suggesting that this clinical entity may be an emergent allergological condition rather than an occasional finding. The most common symptoms complained of in our population were cutaneous (51 patients), gastrointestinal (87 patients) and other systemic clinical manifestations (37 patients). Furthermore, 16 out of the 98 SNAS patients (16.3%) presented IgE-mediated food allergy with a statistically significant association (X2=16.950; P<.0001), therefore suggesting underlying cross-facilitating pathways. These findings need confirmation on wider populations but may help allergists to suspect, during common clinical practice, that cutaneous and extra-cutaneous symptoms may be referred to nickel intake and deserve specific in-depth investigation.

Nickel-Related Intestinal Mucositis in IBS-Like Patients: Laser Doppler Perfusion Imaging and Oral Mucosa Patch Test in Use

“…There is growing awareness that some gastrointestinal IBSlike symptoms, as well as extra-intestinal manifestations, may be induced by the ingestion of Ni-containing food [4,23]. It is also well known that foods rich in Ni come mainly from the Mediterranean diet inscribed on the Intangible Cultural Heritage List of UNESCO, therefore making this issue global.…”

“…On the other hand, also the gastrointestinal tract can represent a route of exposure to Ni [4] inducing SNAS, which is characterized not only by diffused eczematous lesions called systemic contact dermatitis but also by extracutaneous signs and symptoms. Apart from less common respiratory and neurological manifestations, Ni-related symptoms in SNAS are mainly gastrointestinal SNAS.…”

Nickel Allergy in Adults in the US

“…104 Systemic nickel allergy syndrome may present as a worsening of allergic contact dermatitis (ACD), atopic dermatitis, and potentially with extracutaneous symptoms (gastrointestinal, respiratory, and neurological). 105 Notably, the foods with the highest nickel content (9100 Kg/ serving) include sunflower seeds, oat-based cereals, beans, and chocolate. 104 Low nickel diets, as well as oral desensitization regimens, and removal of implanted devices have been used as treatments.…”

Complementary Intradermal and Patch Testing for Increased Diagnostic Accuracy of Nickel Allergy in Non-Celiac Wheat Insensitivity

“…SNAS encompasses a spectrum of clinical presentations (respiratory, gastrointestinal, genitourinary, hematologic) that occur once a nickel-sensitized individual has had continuous exposures to nickel through diet, inhalation, or implantation [6,7]. The most common presentations of SNAS include gastrointestinal symptoms (89%) and cutaneous symptoms (52%).…”

“…A positive nickel patch test in a patient whose symptoms resolve upon instituting a low nickel diet (and recur with positive nickel oral provocation test) is thought to be highly suggestive of SNAS. Clinical improvement following implementation of low nickel diets where nickel-rich foods are eliminated (e.g., legumes (lentils, peas, beans), tomatoes, nuts, cocoa, oats, and whole wheat) [6] are further indication of the diagnosis [5]. …”