Sensitivity and specificity of the nickel spot (dimethylglyoxime) test.
BACKGROUND
The accuracy of the dimethylglyoxime (DMG) nickel spot test has been questioned because of false negative and positive test reactions. The EN 1811, a European standard reference method developed by the European Committee for Standardization (CEN), is fine-tuned to estimate nickel release around the limit value of the EU Nickel Directive from products intended to come into direct and prolonged skin contact. Because assessments according to EN 1811 are expensive to perform, time consuming, and may destruct the test item, it should be of great value to know the accuracy of the DMG screening test.


OBJECTIVE
To evaluate the sensitivity and specificity of the DMG test.


METHODS
DMG spot testing, chemical analysis according to the EN 1811 reference method, and X-ray fluorescence spectroscopy (XRF) were performed concomitantly on 96 metallic components from earrings recently purchased in San Francisco.


RESULTS
The sensitivity of the DMG test was 59.3% and the specificity was 97.5% based on DMG-test results and nickel release concentrations determined by the EN 1811 reference method.


CONCLUSIONS
The DMG test has a high specificity but a modest sensitivity. It may serve well for screening purposes. Past exposure studies may have underestimated nickel release from consumer items.
National Allergy Research Centre, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, University of Copenhagen, Gentofte, Denmark. jacpth01@geh.regionh.dk
Jacob P
JP
Thyssen
Lizbet
L
Skare
Lennart
L
Lundgren
Torkil
T
Menné
Jeanne D
JD
Johansen
Howard I
HI
Maibach
Carola
C
Lidén
D002623:Chemistry Techniques, Analytical; D017449:Dermatitis, Allergic Contact / Q000209:etiology*; D006801:Humans; D009532:Nickel / Q000032:analysis* / Q000633:toxicity*; D010091:Oximes / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013542:Sweat / Q000737:chemistry
D010091:Oximes; C013501:dimethylglyoxime; D009532:Nickel