To Bruise or Not to Bruise: That Is the Question

When the pulsed-dye laser was first used in the late 1980s for the treatment of port wine stains, a 450-ms pulse duration was employed, which effectively caused thermal injury to the blood vessels but virtually always caused rupture, with resulting purpura. The development of longer–pulse-duration pulsed-dye lasers allowed blood vessels to be heated more slowly, which prevented red cell leakage and purpura. The important clinical question that arose immediately was whether purpura-free doses would be as effective as purpuragenic doses in improving facial telangiectasia.

These researchers performed a split-face, bilateral, paired comparison of multiple, low-fluence, subpurpuric passes versus a single, high-fluence, purpuric pass. Nine patient…