Alitretinoin for the Treatment of Lichen Amyloidosis: A Retrospective, Observational Study and an In Vitro Study

Background: Lichen amyloidosis (LA) is the most common form of localized cutaneous amyloidosis, often accompanied by severe pruritus. Treatment options are limited, and alitretinoin, a systemic retinoid, has shown promise in managing refractory cases. Objective: This study aimed to evaluate the efficacy of alitretinoin in treating LA and its effects on keratinocytes. Methods: We conducted a retrospective analysis of 13 patients diagnosed with LA treated with alitretinoin. In addition, an in vitro study assessed the impact of alitretinoin on keratinocyte inflammation markers. Results: Of the 13 patients, 4 (30.77%) achieved complete clearance of lesions, demonstrating excellent improvement. The remaining 9 (69.23%) showed substantial improvement, with almost clear or mild residual lesions. In vitro, alitretinoin significantly decreased levels of IL‐33, periostin, CCL5, and PTGES. Conclusion: Alitretinoin demonstrated effectiveness in treating LA, with favorable outcomes in both clinical and in vitro settings. These findings support alitretinoin as a viable treatment option for LA.