Pilot Study Finds Adding Topical Imiquimod To Laser Therapy Improves The Response Of Port Wine Stain Birthmarks

Two-thirds of all port wine stain birthmarks occur on the face. As such, there is a strong need for an effective, long-lasting treatment that safely fades these reddish-purple skin lesions that can have a huge impact on a patient's physical and emotional well-being. Now, a new study evaluating the combined use of pulsed dye laser (PDL) therapy and topical Imiquimod to treat port wine stain birthmarks shows promising results.

Wausau, Wisconsin (PRWEB) November 18, 2008 -- Two-thirds of all port wine stain birthmarks occur on the face. As such, there is a strong need for an effective, long-lasting treatment that safely fades these reddish-purple skin lesions that can have a huge impact on a patient's physical and emotional well-being. Now, a new study evaluating the combined use of pulsed dye laser (PDL) therapy and topical Imiquimod to treat port wine stain birthmarks shows promising results.
   
In the article entitled "Pilot Study Examining the Combined Use of Pulsed Dye Laser and Topical Imiquimod Versus Laser Alone for Treatment of Port Wine Stain Birthmarks," researchers studied 20 Asian patients with port wine stain birthmarks who were treated with either regimens of PDL plus Imiquimod; PDL alone; or Imiquimod alone. Recently published in Lasers in Surgery and Medicine (October 2008 issue), the peer-reviewed professional journal of the American Society for Laser Medicine and Surgery, the clinical study was headed by lead investigator Cheng-Jen Chang, MD, PhD, associate professor in the department of plastic surgery at Chang Gung Memorial Hospital, Chang Gung University in Taipei, Taiwan.

"Although the pulsed dye laser has become the treatment of choice for port wine stain birthmarks, only 10 percent to 20 percent of patients obtain 100 percent fading of these birthmarks even after multiple treatments," said Martin C. Mihm, Jr., MD, co-author and clinical professor of dermatopathology at Harvard Medical School in Boston, Mass. "A key problem is that port wine stain birthmarks can recur after laser therapy due to reformation of blood vessels. This pilot study set out to determine if adding a topically applied angiogenesis inhibitor that works by disrupting the body's normal wound healing response would prevent a reoccurrence."
   
Imiquimod is a topical immune response modifier agent that is approved by the U.S. Food and Drug Administration (FDA) for the treatment of actinic keratoses, superficial basal cell carcinomas and genital warts. Imiquimod is also known to have anti-angiogenic (inhibits the growth of new blood vessels) properties which might prove to be very useful in preventing port wine stain blood vessel recurrence following PDL therapy. The present study represents an off-label use of Imiquimod.

A key problem is that port wine stain birthmarks can recur after laser therapy due to reformation of blood vessels. This pilot study set out to determine if adding a topically applied angiogenesis inhibitor that works by disrupting the body's normal wound healing response would prevent a reoccurrence.

Clinical Study Results
A total of 20 patients ranging in age from three to 56 with port wine stain birthmarks had three test sites placed on their lesion which were treated using the following regimens: 1) PDL plus Imiquimod; 2) PDL alone; and 3) Imiquimod alone. For the PDL plus Imiquimod and the Imiquimod alone test sites, patients were instructed to apply Imiquimod topically as a thin layer once daily for one month following therapy.
   
In order to objectively assess the efficacy of the fading of the port wine stain birthmarks, a dermatological measurement tool was used to calculate the hemoglobin-index (or the amount of blood in the lesions) in the three different test sites at each follow-up visit - one, three, six and 12 months following PDL therapy. The individual performing these measurements was blinded as to the test sites' treatment regimen.
   
Based on the amount of blood in the lesions at each follow-up visit, test sites which received the combined PDL and Imiquimod treatment regimen experienced a better and statistically significant degree of fading over time as compared to test sites that received PDL therapy alone or Imiquimod alone. For the test sites receiving Imiquimod therapy alone, no drug-induced fading of port wine stains was observed.

Researchers reported that the enhanced fading obtained on the port wine stain test sites treated with PDL and Imiquimod was maintained up to 12 months following laser therapy. In addition, the combined therapy was found to be safe with only minor side effects which resolved in all patients without medical intervention.

"While more clinical trials need to be conducted to confirm these results, we are encouraged by these early findings and expect that future studies using different dosing measurements of Imiquimod or more frequent application of the drug could further enhance patient outcomes," said Dr. Mihm. "Since all tumors rely on blood vessel growth, the implications of this study are further evidence of the importance of anti-angiogenesis in inhibiting the growth of other types of tumors, even cancerous tumors, with this therapy."
Although the favorable results using PDL and Imiquimod for fading of port wine stain birthmarks were only studied in Asian patients, study collaborator J. Stuart Nelson, MD, PhD, professor of surgery and biomedical engineering at the Beckman Laser Institute and Medical Clinic, University of California, Irvine, in Irvine, Calif., added that similar results would be expected in patients of any ethnic background.
    
"Generally, Asians and other patients with darker skin types do not respond as well to PDL therapy as Caucasians and other patients with lighter skin types," said Dr. Nelson. "The fact that the Asian patients in this study experienced such favorable results in the fading of their port wine stains with this combined therapy is extremely encouraging for the future treatment of these birthmarks, which traditionally have been difficult to treat."

The American Society for Laser Medicine and Surgery (ASLMS) is the world's preeminent resource for laser research, safety, education, and clinical knowledge. Founded in 1980, ASLMS promotes excellence in patient care by advancing clinical application of lasers and related technologies. For more information and physician referrals, please log on to the Society's website: www.aslms.org.

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