Mutoh Tomoyuki, Mitsui Hidetoshi, Fujii Hiroshi
Department of Rheumatology, Osaki Citizen Hospital, Osaki, Japan.
Department of Dermatology, Osaki Citizen Hospital, Osaki, Japan.
JMA J. 2025 Apr 28;8(2):641-645. doi: 10.31662/jmaj.2024-0412. Epub 2025 Feb 28.
Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM) is characterized by mild or absent muscle involvement and unique skin lesions such as cutaneous ulceration and palmar papules, commonly associated with rapidly progressive interstitial lung disease (RP-ILD), causing fatal outcomes. Spontaneous intramuscular hemorrhage (SIH) is an extremely rare but severe complication that remains under-recognized in DM. Here, we report a case of multiple SIH in a 72-year-old Japanese woman with anti-MDA5 antibody-positive DM and RP-ILD. The patient initially presented with fever, fatigue, and abnormal liver function, leading to a provisional diagnosis of autoimmune hepatitis. Following a 3-week moderate-dose prednisolone treatment, bilateral thigh hematomas suddenly developed without trauma or anticoagulant therapy. Laboratory findings revealed elevated creatine kinase and ferritin levels, reduced factor XIII (F13) activity, and anemia. Computed tomography (CT) imaging showed hematomas in multiple muscles and ILD. Although high-dose prednisolone administration gradually ameliorated the intramuscular hemorrhage, skin manifestations indicative of DM and dyspnea on exertion emerged after tapering prednisolone. Exacerbation of ILD was observed on CT imaging. Comprehensive analysis detected anti-MDA5 and anti-Ro52 antibodies without anti-F13 autoantibody, eventually leading to the diagnosis of anti-MDA5 antibody-positive DM with SIH and RP-ILD. Despite aggressive immunosuppressants, she died of RP-ILD-related respiratory failure. This case highlights the importance of considering DM as a differential diagnosis and investigating cutaneous manifestations indicative of DM in cases where the SIH etiology is unclear. Evaluation of myositis-specific and myositis-associated autoantibodies is crucial to ensure adequate diagnosis when SIH associated with DM is highly suspected.
抗黑色素瘤分化相关基因5（MDA5）抗体阳性的皮肌炎（DM）的特征是肌肉受累轻微或无肌肉受累，以及独特的皮肤病变，如皮肤溃疡和掌丘疹，通常与快速进展性间质性肺病（RP-ILD）相关，可导致致命后果。自发性肌肉内出血（SIH）是一种极其罕见但严重的并发症，在皮肌炎中仍未得到充分认识。在此，我们报告一例72岁日本女性抗MDA5抗体阳性的皮肌炎合并RP-ILD并发多处SIH的病例。患者最初表现为发热、疲劳和肝功能异常，初步诊断为自身免疫性肝炎。在接受3周中等剂量泼尼松龙治疗后，双侧大腿突然出现血肿，无外伤或抗凝治疗史。实验室检查发现肌酸激酶和铁蛋白水平升高，凝血因子 XIII（F13）活性降低，伴有贫血。计算机断层扫描（CT）成像显示多处肌肉有血肿及ILD。尽管大剂量泼尼松龙治疗逐渐改善了肌肉内出血，但在泼尼松龙减量后出现了提示皮肌炎的皮肤表现和活动后呼吸困难。CT成像显示ILD加重。综合分析检测到抗MDA5和抗Ro52抗体，但无抗F13自身抗体，最终诊断为抗MDA5抗体阳性的皮肌炎合并SIH和RP-ILD。尽管使用了积极的免疫抑制剂，她仍死于RP-ILD相关的呼吸衰竭。该病例强调了在SIH病因不明的情况下，将皮肌炎作为鉴别诊断并调查提示皮肌炎的皮肤表现的重要性。当高度怀疑与皮肌炎相关的SIH时，评估肌炎特异性和肌炎相关自身抗体对于确保准确诊断至关重要。
