A 41-year-old man presented to the dermatology clinic with a 1-month history of erythematous, pruritic papules on the abdomen. The periumbilical skin had 2 symmetric erythematous plaques with overlying scaly, hyperkeratotic tissue and eczematous papules (Figure 1A). The lesions were confined to the skin in contact with a metallic belt buckle purchased 3 months before. Positive patch test (++) for nickel sulfate (5.0%) in petroleum confirmed contact dermatitis to nickel (Appendix 1, available at www.cmaj.ca/ lookup/doi/10.1503/cmaj.220260/tab-related-content). We prescribed a 7-day course of mometasone furoate (0.1%) cream, which led to a substantial improvement (Figure 1B). We recommended that the patient avoid future contact with nickel-containing accessories and use brass or plastic fasteners, belts and buckles instead.
A meta-analysis of 20000 people from the general population who were patch tested confirmed a 20% prevalence of contact allergy, with nickel being the most common allergen (11.4%). (1) Prevalence is higher in women and people with atopic disorders. (2) Nickel allergic contact dermatitis results from...