Prevalence of Contact Allergy to Nickel: A Retrospective Chart Review.

Background: No recent studies reporting nickel sensitivity prevalence in Canadians exist.

Objectives: The aim of this study was to quantify nickel sensitivity prevalence in patients at a patch test clinic in Vancouver.

Methods: Retrospective chart review of 3263 patients patch tested for nickel sensitivity at our clinic in Vancouver between 2008 and 2020.

Results: In total, 24.3% (n = 792 of 3263) of patients were sensitive to nickel. Nickel sensitivity significantly increased over time from 24.3% to 27.9% from 2008 to 2020. Nickel-sensitive patients were significantly more likely to be women (P < 0.001), between the ages of 19 and 64 years (P = 0.010), and have dermatitis affecting the face (P = 0.001) and hands (P = 0.001). Nickel-sensitive patients were significantly less likely to be 65 years or older (P = 0.001) and have dermatitis affecting the legs (P = 0.002). Approximately half of nickel-sensitive reactions were new positive reactions at the second reading.

Conclusions: Nickel sensitivity occurred in approximately one quarter of patients and significantly increased over time. Nickel-sensitive patients were more likely to be women, aged 19 to 64 years, and have dermatitis affecting the face and hands; and less likely to be 65 years or older and have dermatitis affecting the legs.