COMPARISON OF 3 METHODS OF USING THE DERMAPIK WITH THE STANDARD PRICKMETHOD 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 ei ther a punch or scratch device. A third method- the prick, uses the de vice similarly to standard prick testing with the bifurcated needle. O bjective: To compare three methods of using the DermaPIK for epicutane ous skin testing with the bifurcated needle, Methods: Twenty volunteer s with a mean age of 30 years (range 6 to 45) were skin tested using s aline and histamine. Each test was done in triplicate on the back. Dis comfort for each technique was rated on a scale from 0 to 100. Wheal a nd erythema were measured at 15 minutes and a photograph was taken. Re sults: The scratch method was rated highest in discomfort. The mean co efficient of variation for the punch method was 39.2% for erythema whi ch was significantly higher than for the other methods (P < .0001). Th e 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 metho ds (P < .001). There was no difference between the prick method and th e 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 an d precision.