Increased sensitivity of patch testing by standardized tape stripping beforehand: a multicentre diagnostic accuracy study.
BACKGROUND
As a modification of patch testing, the strip patch test was established to obtain more sensitive and reliable test results. Comparative data on diagnostic accuracy for both tests are missing.


OBJECTIVE
To compare the diagnostic accuracy of strip patch tests and patch tests in detecting sensitizations in patients with suspected allergic contact dermatitis by using patient history as the reference standard.


METHODS
In a multicentre, prospective, investigator-blinded study 790 patients were enrolled. The defined reference standard was established prior to patch testing. Patch tests were performed with nickel sulfate, potassium dichromate, and lanolin alcohol. Duplicate tests were simultaneously performed on both sides of the back, of which one randomly chosen side was tape stripped beforehand, according to a standardized procedure. Primary outcome was the difference in sensitivity between strip patch test and patch test.


RESULTS
Seven hundred and eighty-seven patients were included in the analysis. Strip patch tests detected considerably more sensitization to nickel sulfate and potassium dichromate than patch tests: differences of sensitivities were 16.4% (95% CI, 8.7-24.1%) for nickel sulfate and 25.0% (95% CI, 8.9-41.0%) for potassium dichromate, both favouring the strip patch test.


CONCLUSIONS
The standardized strip patch test proved to be accurate and clinically safe and is promising to improve diagnosis of allergic contact dermatitis beyond the patch test.
Department of Dermatology and Allergology, Ruhr University Bochum, Bochum, Germany. h.dickel@klinikum-bochum.de
Heinrich
H
Dickel
Burkhard
B
Kreft
Oliver
O
Kuss
Margitta
M
Worm
Stephanie
S
Soost
Jochen
J
Brasch
Wolfgang
W
Pfützner
Jürgen
J
Grabbe
Irena
I
Angelova-Fischer
Peter
P
Elsner
Joachim
J
Fluhr
Peter
P
Altmeyer
Johannes
J
Geier
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007509:Irritants; D007809:Lanolin; D008297:Male; D008875:Middle Aged; D009532:Nickel; D010328:Patch Tests / Q000379:methods*; D011192:Potassium Dichromate; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D053832:Surgical Tape; D055815:Young Adult
D000485:Allergens; D007509:Irritants; D009532:Nickel; D007809:Lanolin; D011192:Potassium Dichromate