Polymyalgia Rheumatica

Polymyalgia rheumatica (PMR) is an immune-mediated inflammatory disease of unknown origin sharing pathogenetic and epidemiological features with giant-cell arteritis. The incidence of PMR increases after the age of 50 and it affects more frequently women. PMR is characterized by aching and morning stiffness in the cervical region and shoulder and pelvic girdles due to inflammation of periarticular structures of the glenohumeral and hip joints, mainly bursitis and tenosynovitis. Laboratory markers are non-specific but acute phase reactant levels are typically increased. Several imaging techniques, including ultrasound, magnetic resonance imaging (MRI), and positron emission tomography with computed tomography (PET-CT) can contribute to the diagnosis of PMR. Since several conditions can mimic PMR, this condition requires careful differential diagnosis. Oral glucocorticoids are the cornerstone of PMR treatment at initial daily doses of prednisone of 15 mg. Methotrexate and tocilizumab have shown efficacy in glucocorticoid-dependent or refractory cases. In 2012, European League Against Rheumatism/American College of Rheumatology preliminary classification criteria for PMR were proposed.