Inclusion Body Myositis

Inclusion body myositis is a progressive inflammatory myopathy most commonly affecting adults over 50, characterized by distal and proximal muscle weakness, particularly in the quadriceps and finger flexors. Pathophysiology includes inflammatory infiltrates and intracellular protein aggregates leading to myofiber degeneration. Diagnosis is based on clinical presentation, elevated serum CK, electromyography, and muscle biopsy demonstrating rimmed vacuoles. Management is largely supportive, as immunosuppressive therapy is generally ineffective. Prognosis is chronic progressive weakness with preserved life expectancy.