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


OBJECTIVE
To present early findings with a newly developed cobalt spot test.


RESULTS
A cobalt spot test based on disodium-1-nitroso-2-naphthol-3,6-disulfonate was able to identify cobalt release at 8.3 ppm. The test may also be used as a gel test if combined with an agar preparation. We found no false-positive reactions when testing metals and alloys known not to contain cobalt. However, one cobalt-containing alloy, which elicited cobalt dermatitis in cobalt-allergic patients, was negative upon cobalt gel testing.


CONCLUSIONS
The cobalt test detects amounts of cobalt release that approximate the elicitation concentration seen in cobalt-allergic patients. It may serve as a useful tool in dermatology offices and workplaces.
Thyssen
Jacob P
JP
National Allergy Research Centre, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, 2820 Gentofte, Denmark. jacpth01@geh.regionh.dk
Menné
Torkil
T
Johansen
Jeanne D
JD
Lidén
Carola
C
Julander
Anneli
A
Møller
Per
P
Jellesen
Morten S
MS
D000497:Alloys / Q000009:adverse effects / Q000737:chemistry*; D003035:Cobalt / Q000032:analysis* / Q000633:toxicity; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D009282:Naphthalenesulfonates / Q000737:chemistry; D010328:Patch Tests / Q000592:standards
D000497:Alloys; D009282:Naphthalenesulfonates; D003035:Cobalt; C004200:1-nitroso-3,6-disulfonate