UC Irvine

Roughly 400,000 children each year are born with port wine stain (PWS) birthmarks, which are skin capillary malformations characterized by a pink-reddish color that develop into purple nodules if left untreated. While PWS birthmarks can be found anywhere on the body and are typically non-life threatening, a large majority (~90%) present on the head and neck regions and can lead to complications including dental abnormalities and may be associated with capillary malformations in other organs such as the eyes (glaucoma), and brain (seizures). Due to the unsightly nature of PWS, people that have them on exposed areas of skin (face, neck, arm or leg regions) can endure immense psychological and social suffering. The current gold standard treatment for PWS in the US is laser irradiation using the pulsed dye laser (PDL). Treatment of PWS with the PDL has limited efficacy; many patients undergo 15 or more laser treatments without seeing full clearance of the PWS, demonstrating the need to investigate alternative therapies.

In my dissertation research, I investigated alternatives to PDL treatment for PWS, including photodynamic therapy (PDT), combined PDT/PDL protocols, and alternative light based treatments. PDT has demonstrated promise towards achieving better treatment outcomes for PWS birthmarks, however, careful selection of treatment parameters is needed to avoid unwanted side effects. I performed preclinical studies of PDT using two photosensitizers, NPe6 and Hemoporfin, to better develop safe treatment parameters. I then investigated a combined PDT/PDL protocol and determined that a synergistic effect exists between the PDT and PDL protocols, illustrating that this combined approach leads to a desired treatment outcome while minimizing side effects. To better understand the PDT treatment mechanisms in skin, I also studied the depth of injury caused by NPe6-mediated PDT in preclinical models and found a direct relationship between depth of vascular injury and light dose administered. Finally, in investigating alternatives to the PDL, I studied the use of intense pulsed light (IPL) and performed a direct comparison study to the PDL. I used computational models to characterize the predicted performance of the IPL and performed experimental studies in preclinical models.