Yu W, Zhu J, Han Y, et al. - In the present study, the researchers sought to examine the morphological and anatomical characteristics of port-wine stains (PWSs) treated by pulsed dye laser (PDL) based on their location on the limb and suggest a possible explanation for the difference in PDL treatment efficacy. PWSs positioned proximally on the limb also respond better to treatment with PDL compared with those positioned distally on the limb. Self-controlled case series aimed at assessing the localization-based efficacy and anatomic characteristics of PWSs in response to PDL treatment have not been reported before.