Nickel and cobalt release from jewellery and metal clothing items in Korea

Abstract

Background: In Korea, the prevalence of nickel allergy has shown a sharply increasing trend. Cobalt contact allergy is often associated with concomitant reactions to nickel, and is more common in Korea than in western countries.

Objective: The aim of the present study was to investigate the prevalence of items that release nickel and cobalt on the Korean market.

Materials and methods: A total of 471 items that included 193 branded jewellery, 202 non-branded jewellery and 76 metal clothing items were sampled and studied with a dimethylglyoxime (DMG) test and a cobalt spot test to detect nickel and cobalt release, respectively.

Results: Nickel release was detected in 47.8% of the tested items. The positive rates in the DMG test were 12.4% for the branded jewellery, 70.8% for the non-branded jewellery, and 76.3% for the metal clothing items. Cobalt release was found in 6.2% of items. Among the types of jewellery, belts and hair pins showed higher positive rates in both the DMG test and the cobalt spot test.

Conclusion: Our study shows that the prevalence of items that release nickel or cobalt among jewellery and metal clothing items is high in Korea.

Keywords: allergy; cobalt; cobalt spot test; contact dermatitis; dimethylglyoxime test; jewellery; nickel.