Polymyalgia Rheumatica, an Age-Related Rheumatic Disease

Abstract

Polymyalgia rheumatica (PMR) is an age-related chronic inflammatory disease with rheumatic features at the fore. In addition to the high-grade systemic inflammation, it is characterized by typical “polymyalgic” musculoskeletal symptoms, including diffuse and severe pain and prolonged morning stiffness of the shoulder girdle, pelvic girdle, and neck. PMR is a member of the so-called giant cell arteritis complex; however, in spite of the marked systemic inflammation in PMR, the local vasculitis process aborts. The pathological background is synovitis, with a predominant inflammation of the extra-articular synovial structures. Synovitis of PMR is mild, transient, and non-erosive. Distal musculoskeletal symptoms are also observed but are more variable and less recognizable than the predominant proximal polymyalgic syndrome. PMR often overlaps with elderly-onset seronegative arthritides, elderly-onset rheumatoid arthritis, late-onset seronegative spondylarthritis, and the RS3PE1 syndrome. Although glucocorticoids are the cornerstone of PMR therapy, considerable hope is attached to tocilizumab, an IL-6 receptor inhibitor.