The purpose of this study is to improve port wine stain (PWS) therapeutic outcome in response to pulsed dye laser (PDL) therapy by comparison of 577 nm versus 595 nm Wavelengths.

The researchers' specific aim is to determine whether the use of the PDL operating at a wavelength of 577 nm will improve PWS therapeutic outcome as compared to a PDL operating at 595 nm.

PWS are a congenital, progressive vascular malformation of human skin. The pulsed dye laser (PDL) is approved by the Food and Drug Administration (FDA) for the treatment of PWS. However, the degree of PWS blanching seen following PDL treatment remains variable and unpredictable. If the ultimate standard required is complete lesion blanching, the average success rate is below 10%, even after undergoing numerous PDL treatments. Moreover, less than 50% of patients achieve 50% fading of their PWS in response to PDL therapy.

In this single center pilot study, PWS subjects will have half of their PWS treated using a PDL operating at a wavelength of 577 nm. The other half of the PWS will be treated using a PDL operating at a wavelength of 595 nm. The researchers' expect that the PWS treated with the 577 nm PDL will have improved PWS blanching responses than the areas treated with 595 nm PDL. The degree of PWS blanching which will be quantified objectively using visible reflectance spectroscopy (VRS) measurements.

Subjects will be recruited from an outpatient population of subjects with PWS at the Beckman Laser Institute and Medical Clinic, University of California, Irvine. Subjects with the requisite diagnosis of PWS (previously laser-treated or untreated) will be candidates for enrollment.

In this single center pilot study, PWS subjects will have half of their PWS treated using a PDL operating at a wavelength of 577 nm. The other half of the PWS will be treated using a PDL operating at a wavelength of 595 nm.

Both PDL are FDA-approved for PWS laser treatment. Both PDL are manufactured by Candela Laser Corporation (Wayland , MA).

Post-treatment blanching responses as determined quantitatively by visual reflectance spectroscopy (VRS) will be compared with pre-treatment measurements of PWS fractional blood volume.

Further patient treatment will be dictated based on which wavelength resulted in the best therapeutic outcome in terms of PWS blanching. Subjects will be offered the opportunity to continue receiving treatment with the wavelength that produced the base clinical results.

Inclusion Criteria:

• PWS suitable for comparison testing
• Age > 6 months of age; minor will be accompanied in the room by parents or guardians during laser treatment
• Apparent good health as documented by medical history
• Ability to understand and carry out subject instructions

Exclusion Criteria:

• History of photodermatoses or skin cancer
• Any therapy within the previous two months to the proposed PWS treatment sites
• Inability to understand and carry out instructions