Improvement of cutaneous and gastrointestinal symptoms in Crohn’s disease following a low-nickel diet: A case report and narrative review

Nickel, a ubiquitous trace metal, is a common contact allergen that, for some people, can also be systemic, resulting primarily in cutaneous and gastrointestinal (GI) symptoms. This article presents a narrative review of the relevant literature on systemic nickel allergy syndrome and low-nickel diets (LNDs) and reports an autobiographical case of a 45-year-old male with a 25-year history of Crohn’s disease (CD) and contact nickel allergy. The case details the identification of systemic nickel allergy and the treatment of symptoms related to CD with a LND, implemented using a nickel points scoring system. During the initial 4-week implementation period, considerable reductions in cutaneous (dyshidrotic eczema), GI symptoms and systemic pain were observed. Specifically, the frequency of bowel movements decreased from approximately six or more per day to around three or fewer, and back and neck pain severity dropped drastically from a baseline average of 8 (on a 1–10 scale) to < 2. These findings, along with ancillary improvements in mood and overall well-being, were concurrent with the use of the LND and have remained consistent and sustained at the time of writing, approximately 8 months later. Various diets that are, by nature, low in nickel content have shown promise for the treatment of CD, and this literature review and case report suggest a hypothesis that their efficacy may be related to reduced nickel intake.