Supplementary Material for: Oral isotretinoin for facial discoid dermatosis (FDD): effectiveness, safety, and clinical suitability. Case report of complete response and literature review

Introduction: Facial discoid dermatosis (FDD) is a rare dermatological condition, first described in 2010. Its aetiology remains unknown and it is distinguished by its resistance to several treatments, both topical and systemic. The lack of documentation in the medical literature makes this disease a significant diagnostic and therapeutic challenge. Case presentation: A 51-year-old woman consulted for the appearance of pruritic skin lesions on the face, neck and upper chest of 2 months' duration. She underwent various topical and systemic therapies without complete resolution over a period of 9 months. Histological examination revealed psoriasiform irregular epidermal hyperplasia, mild spongiosis, parakeratosis and hypogranulosis. In the superficial dermis, perivascular lymphocytic infiltrates were observed. Given the findings described and the refractoriness to multiple treatments employed, the diagnosis of FDD was established. Low-dose isotretinoin administration led to complete resolution of the skin lesions, with no associated adverse effects observed during the course of treatment. Conclusion: We present the first reported case of FDD in a middle-aged woman who was successfully treated with low-dose isotretinoin, resulting in complete resolution of the condition. This finding underlines the potential of isotretinoin as an effective and well-tolerated therapeutic option, especially in women of childbearing age. We also provide a comprehensive review of the treatments for FDD that have been documented in the literature.引言：面部盘状皮肤病（Facial discoid dermatosis，FDD）是一种罕见的皮肤病，于2010年首次被报道。其病因尚未明确，且以对多种局部及系统治疗均产生抵抗为特征。由于医学文献中相关记载匮乏，该病成为诊断与治疗领域的重大难题。 病例报告：一名51岁女性因面部、颈部及上胸部出现瘙痒性皮损就诊，病程已达2个月。患者曾接受多种局部及系统治疗，但在9个月的治疗周期内皮损并未完全消退。组织病理学检查显示存在银屑病样不规则表皮增生、轻度海绵水肿、角化不全及颗粒层减少。真皮浅层可见血管周围淋巴细胞浸润。结合上述临床表现与对多种治疗的抵抗性，最终确诊为FDD。给予低剂量异维A酸治疗后，皮损完全消退，治疗全程未观察到相关不良反应。 结论：本文报告了首例经低剂量异维A酸成功治疗并实现病情完全缓解的中年女性FDD病例。这一结果凸显了异维A酸作为有效且耐受性良好的治疗选择的潜力，尤其适用于育龄女性。同时，本文还对文献中记载的所有FDD治疗方案进行了全面综述。