Comparison of three methods of using the DermaPIK with the standard prick method for epicutaneous skin testing.
BACKGROUND
The Greer DermaPIK is a plastic disposable device used for epicutaneous allergy skin testing. Various methods have been proposed for applying this device. The recommended methods are to use it as either a punch or scratch device. A third method- the prick, uses the device similarly to standard prick testing with the bifurcated needle.


OBJECTIVE
To compare three methods of using the DermaPIK for epicutaneous skin testing with the bifurcated needle.


METHODS
Twenty volunteers with a mean age of 30 years (range 6 to 45) were skin tested using saline and histamine. Each test was done in triplicate on the back. Discomfort for each technique was rated on a scale from 0 to 100. Wheal and erythema were measured at 15 minutes and a photograph was taken.


RESULTS
The scratch method was rated highest in discomfort. The mean coefficient of variation for the punch method was 39.2% for erythema which was significantly higher than for the other methods (P < .0001). The scratch method had a mean wheal and erythema to saline of 3.85 +/- 1.3 and 6.23 +/- 2.2 that was significantly larger than the other methods (P < .001). There was no difference between the prick method and the bifurcated needle for discomfort or size of wheal/erythema to saline or histamine.


CONCLUSIONS
The punch method is too imprecise and the scratch method produces considerable dermatographism. The prick method was comparable to the bifurcated needle in discomfort, sensitivity and precision.
Corder
W T
WT
Department of Pediatrics, West Virginia University, Morgantown, USA.
Wilson
N W
NW
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006632:Histamine; D006801:Humans; D008297:Male; D008875:Middle Aged; D012882:Skin Tests / Q000379:methods*; D012965:Sodium Chloride
D012965:Sodium Chloride; D006632:Histamine