Patch testing with cobalt in children and adolescents: North American contact dermatitis group experience, 2001-2018


Jonathan I. Silverberg, Department of Dermatology, George Washington University School of Medicine, Washington, District of Columbia, USA.
Nisha Patel, Department of Dermatology, George Washington University School of Medicine, Washington, District of Columbia, USA.
Erin M. Warshaw, Department of Dermatology, Park Nicollet Health Services, Minneapolis, Minnesota, USA.
Howard I. Maibach, Department of Dermatology, University of California San Francisco, San Francisco, California, USA.
Donald V. Belsito, Department of Dermatology, Columbia University Irving Medical Center, New York, New York, United States.
Joel G. DeKoven, Division of Dermatology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Kathryn A. Zug, Department of Dermatology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
James S. Taylor, Department of Dermatology, Cleveland Clinic, Cleveland, Ohio, USA.
Denis Sasseville, Division of Dermatology, Montreal General Hospital, McGill University, Montreal, Quebec, Canada.
Vincent A. DeLeo, Department of Dermatology, Keck School of Medicine, Los Angeles, California, USA.
Melanie D. Pratt, Division of Dermatology, University of Ottawa, Ottawa, Ontario, Canada.
Margo J. Reeder, Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
Amber R. Atwater, Department of Dermatology, Duke University Medical Center, Durham, North Carolina, USA.
Joseph F. Fowler, Division of Dermatology, University of Louisville, Louisville, Kentucky, United States.
Marie-Claude Houle, Division of Dermatology, Centre Hospitalier Universitaire (CHU) de Québec, Laval University, Quebec City, Quebec, Canada.

Document Type

Journal Article

Publication Date



Contact dermatitis




adolescent; allergic contact; children; cobalt; dermatitis; epidemiology; health; itch; metal; paediatrics; patch test; pruritus; rash


BACKGROUND: Allergic contact dermatitis (ACD) to cobalt is more common in children and adolescents than adults. However, detailed information on sites and sources of cobalt ACD is limited. OBJECTIVES: To assess trends in positive and clinically relevant patch test reactions to cobalt in children and associated patient characteristics, common sources and body sites affected. METHODS: A retrospective analysis of children (<18 years) patch tested to cobalt by the North American Contact Dermatitis Group between 2001 and 2018. RESULTS: Of 1919 children patch tested, 228 (11.9%) and 127 (6.6%) had a positive/allergic or currently relevant patch test reaction to cobalt, respectively. The most common primary body sites affected were scattered generalized (30.0%), face, not otherwise specified (10.6%) and trunk (10.1%). Patients with allergic and currently relevant allergic patch test reactions were more likely to have a primary site of trunk (p = 0.0160 and p = 0.0008) and ears (p = 0.0005 and p < 0.0001). Affected body site(s) varied by cobalt source among patients with currently relevant reactions, especially for less common sources. The most commonly identified sources of cobalt included jewellery, belts and clothing. CONCLUSIONS: Positive patch test reactions to cobalt were common in children. The most common body site was scattered generalized and the sources of cobalt varied by body site.