Muscle vasculitis in patients with polymyalgia rheumatica: Three case series.

Polymyalgia rheumatica (PMR) is a common inflammatory disorder characterized by myalgia/stiffness in proximal hip and shoulder girdle, elevated C reactive protein, and erythrocyte sedimentation rate, but its pathogenesis is not fully elucidated. We report three cases of PMR who do not respond adequately to standard treatment. Those patients had typical symptoms of myalgia and muscle weakness, with elevated C reactive protein in absence of creatine kinase elevation. Muscle specimen showed the findings of vasculitis in all cases; therefore, muscular-limited vasculitis may be an underlying pathology in PMR in those refractory cases.