A directive restricting nickel release from jewelry and other skin-contact products has not been initiated in Thailand or in the United States. The prevalence of nickel and cobalt allergies is increasing, and the main cause of sensitization seems to be jewelry.
We aimed to investigate nickel and cobalt release from jewelry available in Thai marketplaces and to study the factors associated with nickel and cobalt release.
Used costume jewelry items were collected from volunteers. They were tested with the dimethylglyoxime and cobalt tests.
Five hundred fifty-one items, including belt buckles, bracelets, earrings, necklaces, rings, and watches, were tested; 216 (39.2%) gave positive dimethylglyoxime tests, and 206 (37.4%) gave positive cobalt tests. The factors that determined nickel or cobalt release were shopping location and jewelry price. Cobalt-containing jewelry could be identified by its dark color.
A large proportion of the jewelry sold in Thai markets release nickel or cobalt.