Does gold concentration in the blood influence the result  of patch testing to gold?
BACKGROUND
We have recently found a correlation between contact allergy to gold sodium thiosulphate (GSTS) and gold concentration in the blood (B-Au) in a stented population: the higher the B-Au, the stronger the patch-test reaction.


OBJECTIVE
To further investigate the correlation between B-Au and patch-test reactivity to gold.


METHODS
In this provocation control cross-over trial of 24 patients with dermatitis with a known contact allergy to gold, the patients were randomized into two groups where one was topically provoked to gold (15 mg GSTS) and one to the control. All patients were simultaneously patch tested with GSTS in 10 aqueous dilutions (1.1 mg GSTS). Patch-test readings were performed and blood was drawn. After 6 weeks, the experiment was repeated and the group that had previously been provoked with gold was now provoked with the control and vice versa.


RESULTS
B-Au was higher after gold provocation whereas no treatment effect was discerned for minimal eliciting concentration (MEC) or summarized test score (STS). Instead, significant differences in period effect were observed implying higher B-Au and STS and lower MEC on test occasion II. The most likely explanation is the increased B-Au and /or booster effect from test occasion I. There was a correlation between B-Au and MEC: the higher the B-Au, the lower the MEC.


CONCLUSIONS
The correlation between B-Au and MEC indicates that the B-Au is of importance for the skin reactivity to gold.
Ekqvist
S
S
Department of Occupational and Environmental Dermatology, Lund University, Malmö University Hospital, Malmö, Sweden. susanne.ekqvist@med.lu.se
Lundh
T
T
Svedman
C
C
Björk
J
J
Möller
H
H
Nilsson
L A F
LA
Bruze
M
M
D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000009:adverse effects*; D023903:Coronary Restenosis / Q000150:complications; D018592:Cross-Over Studies; D017449:Dermatitis, Allergic Contact / Q000097:blood*; D005260:Female; D006046:Gold / Q000009:adverse effects / Q000097:blood*; D012971:Gold Sodium Thiosulfate / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D015607:Stents; D055815:Young Adult
D018501:Antirheumatic Agents; D006046:Gold; D012971:Gold Sodium Thiosulfate