Nickel allergy and allergic contact dermatitis: A clinical review of immunology, epidemiology, exposure, and treatment

Abstract

Nickel is the most frequent cause of contact allergy worldwide and has been studied extensively. This clinical review provides an updated overview of the epidemiology, exposure sources, methods for exposure quantification, skin deposition and penetration, immunology, diagnosis, thresholds for sensitization and elicitation, clinical pictures, prevention, and treatment. The implementation of a nickel regulation in Europe led to a decrease in the prevalence of nickel allergy, and changes in the clinical picture and disease severity. Nevertheless, the prevalences of nickel allergy in the European general population are approximately 8% to 19% in adults and 8% to 10% in children and adolescents, with a strong female predominance. Well‐known consumer items such as jewellery and metal in clothing are still the main causes of nickel allergy and dermatitis, although a wide range of items for both private and occupational use may cause dermatitis. Allergic nickel dermatitis may be localized to the nickel exposure site, be more widespread, or present as hand eczema. Today, efficient methods for exposure quantification exist, and new insights regarding associated risk factors and immunological mechanisms underlying the disease have been obtained. Nevertheless, questions remain in relation to the pathogenesis, the persistent high prevalence, and the treatment of severe cases.

Prevalence of contact allergy to metals: nickel, palladium, and cobalt in Southern Sweden from 1995–2016

“…It is most likely that the Swedish nickel regulation and the EU nickel directive have had an effect on the decrease in nickel allergy among young people with dermatitis, but owing to the fact that there are still items on the market that release too much nickel, the prevalence is still high, 19.1%, among young females. Daily living habits have changed over the past 20 years and what needed to be controlled in the 1990s was especially nickel in ear piercings, whereas today the source of nickel exposure may have changed . The REACH regulation is still only controlling items that are meant to be in prolonged contact with the skin, where “prolonged contact” is defined as 10 minutes on three or more occasions within 2 weeks, or 30 minutes on one or more occasions within 2 weeks .…”

“…Daily living habits have changed over the past 20 years and what needed to be controlled in the 1990s was especially nickel in ear piercings, whereas today the source of nickel exposure may have changed. 27 The REACH regulation is still only controlling items that are meant to be in prolonged contact with the skin, where "prolonged contact" is defined as 10 minutes on three or more occasions within 2 weeks, or 30 minutes on one or more occasions within 2 weeks. 28 This means that the regulation does not control the amount of released nickel from items meant to have short 37 and large differences in the prevalence between the clinics were found.…”

Nickel allergy is associated with wheezing and asthma in a cohort of young German adults: results from the SOLAR study

“…It is a cell-mediated hypersensitivity, where allergen-specific T-cells and memory T-cells proliferate. These memory T-cells are activated after renewed contact to nickel, resulting in inflammation [1]. With a point prevalence of 9.8-27.5%, it affects women more often than men ( prevalence 2.1-5.1%) in all age groups [2][3][4][5].…”

The Effects of Low-Nickel Diet Combined with Oral Administration of Selected Probiotics on Patients with Systemic Nickel Allergy Syndrome (SNAS) and Gut Dysbiosis

“…Nickel (Ni) is a chemical element widely diffused in the environment [1]. Topical Ni exposure occurs from metallic items, household products, and cosmetics, whereas systemic exposure is possible from food, water, surgical implants, and dental materials [2]. The classical presentation of an Ni allergy is allergic contact dermatitis [2,3], a T-cell-mediated inflammatory skin disease caused by repeated skin exposure to a specific antigen in a sensitized individual [4].…”

“…Topical Ni exposure occurs from metallic items, household products, and cosmetics, whereas systemic exposure is possible from food, water, surgical implants, and dental materials [2]. The classical presentation of an Ni allergy is allergic contact dermatitis [2,3], a T-cell-mediated inflammatory skin disease caused by repeated skin exposure to a specific antigen in a sensitized individual [4]. In sensitized subjects, the ingested Ni-containing compounds, in addition to typical systemic cutaneous lesions, may induce gastrointestinal symptoms like those characterizing inflammatory bowel disease (IBS), i.e., nausea, pyrosis, meteorism, abdominal pain, diarrhea, and constipation.…”