A spot test for detection of cobalt release – early experience and findings

Abstract

Background: It is often difficult to establish clinical relevance of metal exposure in cobalt-allergic patients. Dermatologists and patients may incorrectly assume that many metallic items release cobalt at levels that may cause cobalt dermatitis. Cobalt-allergic patients may be unaware that they are exposed to cobalt from handling work items, causing hand dermatitis.

Consumer leather exposure: an unrecognized cause of cobalt sensitization

“…Nonetheless, it is often difficult to determine the clinical relevance of positive patch test reactions to cobalt chloride, and especially in consumer cases, as the source of cobalt is often not evident. Although the recently developed cobalt spot test has proved to be useful for screening purposes (10), surprisingly few jewellery, hair clasps, mobile phones and work tools release cobalt in significant amounts in market surveys (11)(12)(13). Hence, there seems to be a hitherto overlooked source of cobalt causing the high prevalence of positive test reactions to cobalt in patch test populations.…”

“…First, the brown leather piece was placed on a napkin, and a yellow cobalt test solution containing nitroso R salt was then poured over it (10). Instantly, an orange-red halo was noted around the leather (Fig.…”

The impact of common metal allergens in daily devices

“…Until the very recent development of a cobalt spot test [11], very little evidence of cobalt release from consumer items was available. Although cobalt patch test reactivity is fairly common being observed in up to 10% of patch-tested dermatitis patients [21], the clinical relevance of positive test reactions is only determined in about 25% of patients in Copenhagen, Denmark [22].…”

Mobile Phones: Potential Sources of Nickel and Cobalt Exposure for Metal Allergic Patients

“…The cobalt spot test becomes positive when cobalt is released at *8 ppm. 44 To minimize the risk of false positives, after testing with one reagent, the phone was wiped down with a dry cloth and tested with the second reagent. For each spot test, different areas of the cell phones were tested.…”