NATIONAL HARBOR, MD. Topical application of imiquimod for 8 weeks following pulsed dye laser photothermolysis improved the efficacy of port wine stain treatment among 13 patients in a placebo-controlled study.
Pulsed dye laser (PDL) is the preferred method for treating port wine stains (PWS), but it is limited because multiple treatments are required, and there is often incomplete resolution secondary to posttreatment vessel recurrence.
Imiquimod, a topical immune response modifier, has antiangiogenic properties that could potentially enhance the maintenance of microvascular destruction and, thus, improve the vascular lesion treatment effect in PWS patients when applied during the subsequent wound-healing phase, Dr. Anne Marie Tremaine said at the annual meeting of the American Society for Laser Medicine and Surgery.
Imiquimod (Aldara), manufactured by Graceway Pharmaceuticals LLC, is approved by the Food and Drug Administration for the treatment of genital warts and actinic keratosis. The company provided a research grant for the current PWS study, said Dr. Tremaine of the University of California, Irvine.
The 11 adults and 2 children in the study were randomized to receive either PDL plus 5% imiquimod or PDL plus placebo (vehicle cream). The patients received one PDL treatment and were then instructed to apply 250 mg of cream to an area of less than 25 cm
The treatment was well tolerated by all patients, although two required rest periods at 2 weeks post PDL because of mild crusting before they returned to imiquimod treatment. No serious adverse events were reported.
Laser speckle imaging was used to assess vascular flow. Chromameter measurements were used to quantify changes in skin color, based on the Commission Internationale d'Eclairage (CIE) L*a*b color pace with L* representing reflected light intensity; a*, the color saturation green to red scale; and b*, the color saturation blue to yellow scale.
Average a* values measured at baseline were compared with those at 8 weeks post treatment. The change in a* for PDL plus imiquimod was 0.8, compared with 0.1 for PDL plus placebo. The change in "E," the difference in color between normal and PWS skin calculated to achieve a more standardized form of measurement in seven of the subjects, was 9.1 for PDL plus imiquimod, compared with 1.4 for PDL plus placebo, Dr. Tremaine reported at the meeting.
"The addition of posttreatment imiquimod to PDL therapy may offer the next enhancement in the treatment of port wine stains," she concluded.