Patch test responses evaluated by cutaneous blood flow measurements

Abstract

The cutaneous blood flow in positive standard patch test reactions by use of the laser-Doppler technique was measured in patients with eczeam. The result were compared wtih conventional visual readings to develop a quantitative method. Compared with the basal blood flow in negative or nontested sites, the blood flow was significantly increased .apprx. 5-fold in the doubtful reactions (?+) and .apprx. 10-fold in both weak (1+) and strong (2+) positive reactions. The blood flows in the 1+ and 2+ reactions did not differ significantly from each other. No 3+ positive reactions were measured. This method might be used to separate negative, doubtful and positive reactions, whereas weak and strong positive reactions have to be differentiated by other means.