Supplementary Material for: Immunotherapy-Induced Scarring Alopecia: A Case Series

Introduction Over the last decade, immune checkpoint inhibitors have revolutionized the management of advanced cancers. Immune-induced alopecia has occasionally been reported, with alopecia areata being the most frequently described form, whereas scarring alopecia remains rarely documented. We report a case series of scarring alopecia occurring in patients treated with immune checkpoint inhibitors(ICI) for metastatic melanoma. Case Presentation We conducted a descriptive study with retrospective data collection from January 2023 to December 2025. We enrolled 450 patients who were treated with ICI for metastatic melanomas. Six patients developed scarring alopecia which corresponds to a prevalence of 1.33%. Because of lack of data, only four cases are described in this paper. All patients were female. The mean age at onset of hair fall was 64years [51-82]. The mean duration to symptoms onset after treatment initiation was 29,25 months [26-48]. Alopecia did not lead to discontinuation of treatment in none of our patients. All patients had other immune-related adverse events. Cancer outcome was favourable in all patients. Conclusion Characterizing immune-induced alopecia, particularly scarring alopecia, is crucial for informing patients about the potential psychological impact of hair loss in an oncological context. Furthermore, the possible association between therapeutic efficacy and follicular toxicity warrants further investigation.