Early Recognition of the Gray‐White Sign Prevents Scarring After Hemoporfin‐Mediated Photodynamic Therapy in Pediatric Port Wine Capillary Malformations: A Case Series

BACKGROUND: Hemoporfin-mediated photodynamic therapy (HMME-PDT) is one of the primary treatment modalities for pediatric patients with port wine capillary malformations (port wine CMs) in China. However, it carries a substantial scarring formation risk, particularly in children with delicate skin. Current clinical practice primarily focuses on intraoperative parameter optimization, while postoperative management often remains passive. OBJECTIVES: To highlight the clinical significance of early postoperative signs indicative of impending scarring based on empirical experience, and to emphasize the critical role of early recognition and timely intervention. METHODS: Based on our experience with approximately 3550 pediatric patients undergoing HMME-PDT since 2017, we retrospectively analyzed 15 representative cases to evaluate the clinical course and management outcomes of high-risk signs. Clinical data, photographic documentation, and management outcomes were evaluated to identify key risk factors of scarring and effective interventions. RESULTS: Among the 33 patients (1%) who developed scarring, approximately 88% (29/33) exhibited rapid darkening or gray-white discoloration prior to scar formation. Immediate intervention with topical corticosteroids under occlusion reversed this sign within 72 h. At the median follow-up of 2 months, significant improvement of the original lesions and no scars formation were observed. However, a reference case with only basic wound care resulted in severe scarring. CONCLUSION: Early post-treatment darkening or gray-white discoloration is a key indicator of high scarring risk. Early recognition of this sign, followed by prompt and active postoperative care, is essential to prevent scarring. This study provides important clinical insights into improving safety outcomes for pediatric patients with port wine CMs undergoing HMME-PDT.