Pertinent factors influencing comparative skin tests on the arm

摘要: Abstract 1. The technic which has been found most useful for comparing, by direct skin tests, two solutions differing but slightly in specific activity is described. 2. A dilution of pollen extract 25 per cent stronger than another the same can be identified 66 comparative tests performed with when are placed vertically on arm approximately 4 inches apart and relative positions alternately reversed one-half cases tested. 3. When these extracts compared placing them only 2 apart, solution elicits larger reaction 47.9 solutions, therefore, cannot differentiated from each other this technic. 4. 20 76.3 tested horizontally 1.5 series. 5. upper position shows advantage whealing response to over lower medial lateral, a lesser degree latter instance former. 6. In atopic subjects, histamine position. 7. Tests inserted rows influence more those horizontal rows. This point should taken into consideration routine cutaneous testing hypersensitivity.