Rheumatoid Myositis: A Rare Case Report

Abstract

Rheumatoid Arthritis (RA) and inflammatory myositis are distinct clinical syndromes. Muscle involvement in RA is frequently secondary to therapy with steroids or immune-modulators medication. However, the association of myositis in a treatmentnaive patient with RA is rare. Myositis represents a distinct entity with specific clinical, biological, imaging, and histological patterns. Here, authors describe a case of RA presented with myositis. A 30-year-old female presented with insidious onset gradually progressive to paraparesis lasting for six months. This was preceded by a history of inflammatory arthritis involving small and large joints of the upper and lower extremities. Clinically, she exhibited pure motor weakness of the upper and lower limbs (proximal > distal) with hand, elbow, and knee deformities. Her Anti-Cyclic Citrullinated Peptide antibody (Anti-CCP) and inflammatory markers were elevated. Muscle-specific enzymes were also elevated, along with positive myositis-specific antibodies. Electromyography (EMG) and Magnetic Resonance Imaging (MRI) of the thigh revealed findings consistent with inflammatory myositis. The patient was managed as a case of Rheumatoid Myositis (RM) with steroids, conventional, and biological immune-modulators Disease-Modifying Antirheumatic Drugs (DMARDs). She experienced remarkable improvement in her symptoms and quality of life.