Clinical meaning
Polymyalgia rheumatica (PMR) is a systemic inflammatory condition affecting periarticular structures (bursae, synovium) of the shoulder and hip girdles. Elevated IL-6 drives the acute phase response. PMR is closely associated with giant cell arteritis (GCA), with 15-20% of PMR patients developing GCA, which can cause irreversible vision loss from ophthalmic artery inflammation.
Diagnosis & workup
Diagnostics & workup: - Order ESR and CRP (markedly elevated) - Order CBC (normochromic normocytic anemia common) - Order CK (normal, differentiating from myositis) - Order temporal artery biopsy if GCA suspected - Order ultrasound of shoulders for bursitis - Order liver function tests before steroid initiation
Risk factors: - Age >50 years (rarely before 50) - Female sex (2-3:1) - Northern European descent - Genetic predisposition (HLA-DR4) - Association with giant cell arteritis