Polymyalgia rheumatica is a syndrome closely associated with giant cell (temporal) arteritis. It affects adults > 55. It typically causes severe pain and stiffness in proximal muscles, without weakness or atrophy, and nonspecific systemic symptoms. ESR and C-reactive protein are usually elevated. Diagnosis is clinical. Treatment with low-dose corticosteroids is effective. A dramatic and rapid response to low to moderate doses of prednisone or methylprednisolone supports the diagnosis.
Polymyalgia rheumatica affects adults > 55; the female:male ratio is 2:1.
Because polymyalgia rheumatica is closely associated with giant cell arteritis (see Vasculitis: Giant Cell Arteritis), some authorities consider the two disorders to be different phases of the same process. Polymyalgia rheumatica appears to be more common. A few patients with polymyalgia rheumatica develop giant cell arteritis, but 40 to 60% of patients with giant cell arteritis have polymyalgia rheumatica. Polymyalgia rheumatica may precede, follow, or occur simultaneously with giant cell arteritis.
Etiology and pathogenesis are unknown. Whether symptoms result from vasculitis is unclear; they probably result from low-grade axial synovitis and bursitis.
Symptoms and Signs
Polymyalgia rheumatica is characterized by bilateral proximal aching of the shoulder and hip girdle muscles and the back (upper and lower) and neck muscles. Stiffness in the morning is typical and lasts > 60 min. Shoulder symptoms reflect proximal bursitis (eg, subdeltoid, subacromial) and less often bicipital tenosynovitis or joint synovitis. Discomfort is worse in the morning and is occasionally severe enough to prevent patients from getting out of bed and from doing simple activities. The pain may make patients feel weak, but objective muscle weakness is not a feature of the disorder.
Polymyalgia rheumatica is suspected in elderly patients with typical symptoms, but other possible causes must be excluded. Tests include ESR, C-reactive protein, CBC, thyroid-stimulating hormone levels, and CK. In > 80 % of patients, ESR is markedly elevated, often > 100 mm/h, usually > 50 mm/h (Westergren method). C-reactive protein is also elevated. Electromyography, biopsy, and other tests (eg, rheumatoid factor), which are normal in polymyalgia rheumatica, are sometimes done to rule out other clinically suspected diagnoses.
The following findings in polymyalgia rheumatica distinguish it from
Prednisone started at 15 to 20 mg po once/day results in dramatic improvement, often very rapid (in hours or days), and this response can help support the diagnosis. If giant cell arteritis is thought to be present, the dose of corticosteroids should be higher, and temporal artery biopsy should be done. Treatment effectiveness is monitored by symptoms, ESR, and C-reactive protein. As symptoms subside, corticosteroids are tapered to the lowest clinically effective dose, regardless of ESR. C-reactive protein is more helpful than ESR in guiding response to treatment, because ESR can be persistently elevated in the elderly due to other reasons. Some patients are able to stop corticosteroids in about 2 yr, even sooner without relapse, whereas others require small doses for years. NSAIDs are rarely sufficient.
Some patients who are unable to have their prednisone dose tapered and who have frequent recurrences may benefit from the addition of methotrexate (10 to 15 mg po once/wk, if renal function is normal) or another immunosuppressant such as azathioprine. Adding a second drug in polymyalgia rheumatica or giant cell arteritis is controversial because controlled randomized trials have shown minimal benefit. Trials using anti-TNF drugs (rituximab, infliximab, and adalimumab) have not shown benefit.
In elderly patients, physicians should watch for and treat complications of corticosteroid use (eg, diabetes, hypertension). Patients taking prednisone long term should be given a bisphosphonate to prevent osteoporosis.
Giant cell arteritis may develop at the onset of polymyalgia rheumatica or much later, sometimes even after patients appear cured of the disorder. Therefore, all patients should be instructed to immediately report headache, muscle pain during chewing, and, particularly, visual disturbances to their physician.
Last full review/revision April 2013 by Carmen E. Gota, MD
Content last modified April 2013