Immune-Mediated Necrotizing Myopathy: An Often Misdiagnosed Entity

Immune-mediated necrotizing myopathies (IMNM) are recognized as a subgroup of idiopathic inflammatory myopathies (IIM). IMNM are defined based on a combination of clinical presentation and laboratory studies, requiring a specific myopathological pattern on muscle biopsy for diagnosis. The authors describe a case of a patient with necrotizing myopathy, thought to be immune mediated, highlighting the challenge of its differential diagnosis. As clinical assessment and diagnostic tools sometimes fail to determine whether a necrotizing myopathy is immune mediated, leading to misdiagnosis and a compromise of the optimal therapeutic approach, distinguishing between IMNM and other myopathies is crucial.

Eosinophilic Fasciitis: an Atypical Presentation of a Rare Disease

Objectives: We report an atypical presentation of eosinophilic fasciitis and provide a concise overview of the literature. Materials and Methods: Clinical and laboratory findings in a patient presenting with fever and skin induration were recorded. A deep muscle biopsy was performed in order to confirm the diagnosis. Results: A spontaneous favourable clinical and radiological evolution was observed. Conclusion: The diagnosis of eosinophilic fasciitis is challenging due to the lack of pathognomonic signs and symptoms. As spontaneous resolution has been described, watchful waiting is defendable depending on the clinical presentation. Although magnetic resonance imaging (MRI) can be useful in establishing the diagnosis, a deep muscle biopsy remains the gold standard diagnostic tool.

Polymyositis and the Spectrum of Scleroderma Disorders

Polymyositis (PM) is usually associated to other autoimmune or connective tissue diseases. The authors report the case of a 59-year-old man with pulmonary fibrosis, who presented with constitutional symptoms and gradually developed proximal muscle weakness, Raynaud phenomenon, and dysphagia. Besides creatine kinase (CK) elevation, he had positive anti-Polymyositis-Scleromyositis (PM-Scl) and anti-Sjögren's-syndrome A (SSA) antibodies. Nailfold capillaroscopy showed a scleroderma pattern and muscle biopsy revealed necrosis, regeneration of muscle fibers, and inflammatory infiltrate. Prednisolone was started, with great improvement. Taking into account the overlap features between PM and systemic sclerosis sine scleroderma, it is important to closely monitor the patient for signs of pulmonary and cardiac decompensation.