Inclusion body myositis: A differential diagnosis to consider in patients with myopathy refractory to immunosuppressants. Two case reports

Abstract Inclusion body myositis is part of the group of inflammatory myopathies, representing 30% of this group of diseases, and is considered an orphan disease because its estimated prevalence is less than 5 per 10,000 inhabitants. It produces weakness and atrophy of the proximal and distal muscles. The pathophysiological mechanisms are mainly autoimmune, inflammatory, and degenerative. The cases are presented of two female patients who came to the emergency department due to progressive loss of upper and lower limb strength, and progressive asymmetric muscle weakness.