Skin puncture testing.
SKIN
End-point titration skin puncture testing was performed using whole peanut extract (Greer), undiluted and in 9 serial 1:10 dilutions (original units given by manufacturer, weight/volume). Histamine (1 mg/mL; ALK) and saline (Greer) were used as positive and negative controls, respectively. Lincoln Diagnostics Multi-Test II devices and testing trays were used for skin testing application for all extract dilutions and controls. Skin tests were read 15 minutes after application. The wheal and flare were each circled with a ballpoint pen and transferred to a clear adhesive sheet, from which the largest diameter and its shortest perpendicular diameter for each wheal was measured in millimeters. Skin test wheal area was calculated as π × (average radius)