Port-wine disorders of the skin consisting of ectatic dermal blood vessels.<sup>1</sup>Treatment with a continuous wave (CW) argon laser at wavelengths of 488 and 514.5 nm has demonstrated a 70% cure rate, but also about a 10% incidence of hypertrophic scars.<sup>2-5</sup>A number of other lasers have also been used to treat PWS, such as a millisecond-pulsed ruby laser at 694 nm,<sup>6</sup>a CW dye laser at 540 nm,<sup>7</sup>microsecond-pulsed dye lasers at 577 nm,<sup>8-11</sup>CW neodymium-YAG lasers at 1060 nm,<sup>12</sup>and CW carbon dioxide (CO<sub>2</sub>) lasers at 10 600 nm.<sup>13,14</sup>Histologic results for some of these laser treatments have been published and are summarized in Tables 1 through 5. The incidence of hypertrophic scarring for argon laser treatment is most likely caused by the destruction of the epidermis and upper dermis to a depth of about 0.6 mm,<sup>9</sup>due to