Nickel and Cobalt Release From Children’s Toys Purchased in Denmark and the United States Peter Jensen, MD, PhD,* Dathan Hamann, MD,† Carsten R. Hamann, BA,‡ Morten S. Jellesen, MSc, PhD,§ Sharon E. Jacob, MD,‡||¶ and Jacob P. Thyssen, MD, PhD, DMsc* Background: Nickel is the most common allergen detected by patch testing in children. There is an increasing number of cases in children who have not had exposure to piercing. Although the clinical relevance of nickel patch test reactions in children is sometimes uncertain, continued vigilance to identify new sources of nickel exposure in this age group is important. Recent case reports have described allergic nickel contact dermatitis in children following exposure to toys, but the magnitude of this problem is unknown. Objective: The aim of this study was to evaluate nickel and cobalt release from children’s toys. Methods: We purchased 212 toys in 18 different retail and online stores in the United States and Denmark. Nickel and cobalt release was tested using the dimethylglyoxime and cobalt screening spot tests. Results: A total of 73 toys (34.4%) released nickel, and none released cobalt. Conclusions: Toys are a commonly overlooked source of nickel exposure and sensitization. Therefore, dermatolo- gists, allergists, and pediatricians should consider the role of toys in their evaluation of children with dermatitis, and the parents of children with positive nickel patch test reactions should be told that toys may release nickel and be a potential chemical source in the manifestation of allergic contact dermatitis. I t is well known that adult dermatitis patients often exhibit positive nickel and cobalt patch test reactions. However, nickel and cobalt are also very common allergens detected in chil- dren worldwide. 1 Accordingly, 12.9% of 85 unaffected American children younger than 5 years, 28% of children with dermatitis patch tested by the North American Contact Dermatitis Group, and 27% of 321 three-month-old to 36-month-old Italian chil- dren with dermatitis were found to be sensitized to nickel, respectively. 2Y5 Notably, the evidence in the literature indicates the presence of positive nickel patch tests with uncertain clinical rel- evance. For example, in American children, clinical relevance of the positive nickel patch test reactions was only identified in 26%. 2 Similarly, in French children aged 1 to 15 years, nickel patch test reactivity was common, but positive reactions rarely correlated with actual exposures. 6 Furthermore, when nickel patch testing was performed in 304 asymptomatic 18-month-old Danish infants from the general population, as many as 9% had positive patch test reactions to nickel, despite no identified exposure source. 7 When 21 of the same 26 children with positive nickel test reactions were reevaluated at age 3 and 6 years, only 2 children had persistent reactivity to nickel supporting that infant skin may have a pro- pensity to show false-positive reactions. 8 In line with this, a Danish study from 1963 with similar findings suggested that the nickel sulfate test concentrations should be lowered from 5% to 1% in young children. 9 Collectively, patch test reactivity to nickel can sometimes be incorrectly read as positive in children, but none- theless true nickel sensitization is prevalent, and there remain sources still to be detected. Contact dermatology practitioners should be cognizant of al- lergen exposure sources in children with chronic dermatitis who STUDY 356 DERMATITIS, Vol 25 ¡ No 6 ¡ November/December, 2014 From the *Department of Dermato-Allergology, Gentofte University Hospital, Hellerup, Denmark; ÞDivision of Dermatology, Department of Internal Medi- cine, Wexner Medical Center at The Ohio State University, Columbus þLoma Linda University School of Medicine, CA; §Department of Mechanical Engi- neering, Technical University of Denmark, Kongens Lyngby ||Department of Dermatology, Loma Linda University, and ¶Department of Dermatology, University of California, San Diego. Address reprint requests to: Peter Jensen, MD, PhD, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, DK-2900 Hellerup, Denmark. E-mail: peter.jensen@regionh.dk. Conflict of interests: D. Hamann and C.R. Hamann are first-degree relatives of Curt Hamann, owner of SmartPractice (Phoenix, AZ), a company that produces and distributes nickel and cobalt spot tests. J.P. Thyssen and M.S. Jellesen developed and sold the cobalt spot test to Smarthealth and will receive annual royalties depending on net sales. Funding sources: J.P. Thyssen is a Lundbeck Foundation fellow and is supported by an unrestricted grant. Disclosure: S.E. Jacob served as an independent investigator on the Safety and Efficacy of TRUE Test (Smart Practice; Phoenix, AZ) Panels 1.1, 2.1, and 3.1 in Children and Adolescents, Pediatric Research Equity Act 1 trial. She is currently an investigator on the Pediatric Research Equity Act 2 trial at UCSD/Rady Children’s Hospital and a consultant for Johnson & Johnson. DOI: 10.1097/DER.0000000000000084 Copyright * 2014 American Contact Dermatitis Society. All Rights Reserved. Copyright © 2014 American Contact Dermatitis Society. 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