The Relationship Between the Effectiveness of HMME-PDT and the Dermoscopic Features of Port-wine Stains in Chinese Pediatric Patients: A Retrospective Study

Introduction: Although pulsed dye laser (PDL) remains the gold standard for the treatment of port-wine stains (PWS), hematoporphyrin monomethyl ether photodynamic therapy (HMME-PDT) is another treatment modality that has been shown to be effective in the treatment of PWS. This study aimed to observe the clinical efficacy and therapeutic response of HMME-PDT in the treatment of pediatric Chinese patients with PWS and to analyze the association between the efficacy of therapy and the dermoscopic features of PWS.

Methods: Pediatric patients with PWS and negative HMME skin test were enrolled between December 2017 and May 2021. Patients received an intravenous injection of 5 mg/kg HMME, and lesions were irradiated with 532-nm LED green light with a power density of 70-80 mW/cm² for 20-25 min. Digital photographs and dermoscopic images were taken before and after two treatment sessions, and the clinical response was observed. The relationship between the efficacy of HMME-PDT and the dermoscopic features of PWS was retrospectively analyzed.

Results: A total of 216 pediatric patients (1-14 years) were recruited. Sixty-six patients had the pink type, while 150 had the purple type. After two HMME-PDT sessions, 55 patients showed excellent efficacy (25.46%), 77 patients showed good efficacy (35.65%), 69 patients showed fair efficacy (31.94%), and 15 patients showed no improvement (6.95%). Dotted and globular vessels were highly associated with excellent efficacy (41.82%); linear vessels were mainly associated with good efficacy (54.55%); reticular vessels were mainly associated with fair (55.07%) and mixed vessels were mainly associated with no improvement (26.66%).

Conclusion: HMME-PDT is an effective and safe treatment for pediatric patients with PWS. Dotted and globular vessels as well as linear vessels showed better efficacy compared to the other dermoscopic patterns in patients with PWS. Dermoscopy can provide useful clinical information about treatment outcomes.