2-DIMENSIONAL BLOOD-FLOW DETERMINATIONS IN ALLERGIC REACTIONS USING LASER-DOPPLER SCANNING

The new technique of laser Doppler scanning (LDS) provides a 2-dimensi onal pattern of cutaneous microcirculation, which offers a visual imag e and can quantify the intensity and expansion of perfusion. With the help of this technique, we examined the microcirculatory pattern of Ty pe IV reactions to recall antigens, which were applied using a test st amp (Multitest Merieux). The measurements were performed before applic ation of the test stamp as well as 10 min, 24, 48 and 72 h afterwards. The inflammatory hyperemia was evaluated using LDS and unidimensional laser Doppler fluxmetry. The diameter of the inflammatory infiltrate was quantified by means of palpation, the thickness by means of high-r esolution 20 MHz sonography. The clinically visible erythema was measu red planimetrically. An unspecific hyperemia resulting from the trauma of the stamp revealed no evident infiltrate under sonography 10 min a fter the test application. Depending of the individual reaction, the m ean flux and the expansion of the hyperemia were at their peak after 4 8 h. The flux values were at a maximum in the center of the inflammato ry reaction and dropped continuously toward the periphery. The area of the hyperemia seen in the LDS image was significantly larger than the expansion of the erythema measured planimetrically, but there was a s ignificant correlation. The perfusion correlated significantly with th e infiltration diameter (24 h, 48 h, 72 h) and the infiltration thickn ess 48 h after testing. All in all, it was possible to measure directl y and without touching the skin and to quantify a subclinical pattern of skin perfusion as a response to and inflammatory reaction on a 2-di mensional display. (C) Munksgaard, 1995.