This study aimed to examine the association between piercing and patch test sensitivity to metals (nickel, cobalt, and chromium) in North America.
A retrospective analysis of 9334 patients tested by the North American Contact Dermatitis Group from 2007 to 2010 was conducted.
Nickel sensitivity was statistically associated with at least 1 piercing (risk ratio [RR], 2.52; 95% confidence interval [CI], 2.26–2.81; P < 0.0001) and nickel sensitivity rates increased with the number of piercings (16% for 1 piercing to 32% for ≥5 piercings). Prevalence of nickel sensitivity was higher in females (23.2%) than in males (7.1%), but the association with piercing was stronger in males (RR, 2.38; 95% CI, 1.72–3.30; P < 0.0001) than in females (RR, 1.30; CI, 1.13–1.49; P = 0.0002). Crude analysis indicated that cobalt sensitivity was statistically associated with piercing (RR, 1.63; 95% CI, 1.40–1.91; P < 0.0001); however, stratified analysis showed that this relationship was confounded by nickel. After adjusting for nickel sensitivity, the adjusted risk ratio for piercing and cobalt was 0.78 (not significant). Chromium sensitivity was negatively associated with piercing (RR, 0.60; 95% CI, 0.48–0.75; P < 0.0001).
Piercing was statistically associated with sensitivity to nickel. This relationship was dose dependent and stronger in males. Cobalt sensitivity was not associated with piercing when adjusted for nickel. Chromium sensitivity was negatively associated with piercing.
From the *Department of Dermatology, Veterans Affairs Medical Center, University of Minnesota, Minneapolis, MN; †Division of Dermatology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada; ‡Department of Dermatology, Columbia University, New York, NY; §Dartmouth-Hitchcock Medical Center, Lebanon, NH; ∥Department of Dermatology, University of California, San Francisco, San Francisco, CA; ¶Department of Dermatology, Cleveland Clinic, Cleveland, OH; #Division of Dermatology, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada; **University of Louisville, Louisville, KY; ††Department of Dermatology, University of Cincinnati, Cincinnati, OH; ‡‡Division of Dermatology, University of Ottawa, Ottawa, Ontario, Canada; §§Department of Dermatology, Pennsylvania State University, Hershey, PA; ∥∥Associates in Dermatology, Fort Myers, FL.
Address correspondence to Erin M. Warshaw, MD, MS, Section of Dermatology, Department of Dermatology, Minneapolis Veterans Affairs Medical Center, University of Minnesota Medical School, 1 Veterans Dr, 111K Dermatology, Minneapolis, MN 55417. E-mail: firstname.lastname@example.org.
The authors have no funding or conflicts of interest to declare.
Disclaimer: This material is the result of work supported with resources and the use of facilities at the Minneapolis Veterans Affairs Medical Center, USA. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the United States government.