In the May 2013 issue of the British Journal of Dermatology (2013;168:1040-1046) Gao et al reported on a side-by-side comparison of the use of photodynamic therapy (PDT) versus the pulsed dye laser (PDL) for the treatment of 9 red and 6 purple port-wine stains (PWSs). Fifteen patients (age range, 11–36 years) with PWSs were chosen and 2 adjacent areas of the lesion were randomly assigned to receive either a single PDL treatment or a single PDT session. Eleven lesions were on the neck area, 3 on the upper arm, and 1 on the upper leg. The PDL had a wavelength of 585 nm, and PDT was performed with intravenous hematoporphyrin monomethyl ether and a low-power copper vapor laser (510.6 and 578.2 nm, respectively). The PDT-treated area was done 30 minutes after the PDL-treated area with the other areas being covered. The clinical outcome was measured colorimetrically (blanching rates) and visually.
For the red PWSs the blanching rates at 2 months with the PDL were 11% to 24% and 22% to 55% with PDT (P=.006). For the purple PWSs, blanching rates ranged from 8% to 33% with PDL and 30% to 45% with PDT (P=.0313). Two patients with purple PWSs showed no response to either PDT or PDL. All PDT sites developed localized edema, and all PDL sites developed edema, blistering, purpura, and crusts. Four patients with red PWSs developed hyperpigmentation at the PDL sites.
What’s the issue?
Although there have been studies showing that PDT is an effective treatment of PWSs, this study is a side-by-side quantitative comparison of PDL versus PDT. This study showed that PDT is as effective and as safe as PDL and possibly superior for the treatment of red and purple flat PWSs. This study represents promising steps forward in PDT treatment of dermatologic conditions.
Even though PDL therapy is considered the current standard for treatment of PWSs, this study does show good clearance with PDT. Pulsed dye laser therapy has been more readily available in North America and Europe, though in China, where this study took place, it is not common. The PDT in this study utilized an intravenous photosensitizer, which may not be suitable for all patients. Other limitations of this study include the small sample size and the possibility that treating the lesion halves in close proximity to each other may compound adverse effects. Because each half of the lesion (close proximity to one another) was treated, the effects of each treatment may have been compounded.
Could PDT become an adjuvant treatment in the armamentarium for resistant port-wine stains?