Lesion size is a factor for determining the rate of port-wine stain clearing following pulsed dye laser treatment in adults.

Seventy-four adult patients with facial, truncal, and extremity port-wine stains (PWS) were treated with the flashlamp-pumped pulsed dye laser (PDL) with laser output ranging from 6.0 to 7.5 J/cm2. Response to treatment was analyzed by comparing the area of involvement following each treatment with the area of involvement measured in the first treatment session. All the PWS responded with 25 to 90 percent lightening, and 85.1 percent of patients achieved 25 percent clearing. However, only 36.5 percent achieved 50 percent clearing, and none of the patients achieved 100 percent clearing. None of four patients with PWS greater than 100 cm2 achieved 50 percent clearing following a mean of 17.2 +/- 5.7 treatments. These data emphasize the importance of objectively documenting clinical response to PDL treatment of PWS. Adult patients need to be made aware that complete clearing may not be obtainable by PDL treatment alone. This is especially important for adult patients with PWS larger than 100 cm2.