Approach
Diagnosis is primarily based on history.
History
Polymyalgia rheumatica (PMR) typically occurs in people aged ≥50 years and is more common in women.[2][9] Patients complain of acute onset of pain and stiffness in the neck, shoulder and/or hip girdle region that is worse in the morning. The stiffness may be so severe that getting out of bed is difficult. Stiffness improves to a varying extent throughout the day. Constitutional symptoms such as low-grade fever, weight loss, asthenia, malaise, anorexia, night sweats, and depression may be present. The patient may report asymmetrical joint pain, carpal tunnel syndrome symptoms, and swelling of the hands and feet. It is also important to review the history for symptoms suggestive of giant cell arteritis (GCA), such as unilateral temporal or occipital headaches, scalp tenderness, jaw claudication, or visual symptoms.[9]
Response to corticosteroids
A rapid response to corticosteroids, within 24 to 72 hours of treatment (some criteria provide for 4-7 days), can be very helpful in supporting a diagnosis of PMR and in distinguishing it from other inflammatory disorders.[3][13][17] An incomplete response to low-dose corticosteroids does not rule out the diagnosis.[18]
Physical examination
Patients may exhibit a limited range of active movement of the shoulders and hips due to pain and stiffness. The patient may also have difficulty rising from a chair or the examination table. These symptoms may result from muscle tenderness of the shoulder and hip regions, subacromial bursitis of the shoulders, trochanteric bursitis of the hips, and occasionally an oligoarthritis of the peripheral joints. Sometimes swelling of the fingers and dorsal surfaces of the hands and feet occur as a result of tenosynovitis.[4] Pertinent negative findings of other organ systems should be noted, including the absence of oral ulcers, rashes, cardiopulmonary abnormalities, abdominal abnormalities, and focal neurological findings. Patients should be assessed for signs of GCA: temporal and occipital artery thickening, nodules, and tenderness, as well as scalp tenderness.
Laboratory tests
Elevated serum erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) levels are supportive in the setting of characteristic history and examination findings.[4][11] Normal values in the setting of a characteristic history and examination findings do not rule out the diagnosis, as rarely PMR can present with normal markers of systemic inflammation. Normal ESR and/or CRP in patients with PMR may indicate a milder subset of disease or identification of patients earlier in their disease course.[19]
As hypothyroidism can occasionally present with arthralgias and stiffness, thyroid function tests should be included in the work-up of suspected PMR. As some myeloproliferative diseases may also present similarly to PMR with symptoms of fatigue, bony pain, and elevated ESR, checking FBC and serum protein electrophoresis is also recommended as part of PMR evaluation. Rheumatoid factor and anti-cyclic citrullinated peptide antibodies are ordered if late-onset rheumatoid arthritis is suspected.
In patients in whom shoulder and hip pain predominate, myositis should be considered in the differential diagnosis and creatine phosphokinase (CPK) level should be checked. As rheumatoid arthritis (RA) can more commonly present with shoulder joint stiffness in older individuals, the presence of an inflammatory arthritis involving the finger joints (particularly the PIP and MCP joints) is an indication to check rheumatoid factor and anti-cyclic citrullinated peptide antibody titres; significantly elevated titres of these antibodies increases the likelihood of early rheumatoid arthritis.[20]
How to take a venous blood sample from the antecubital fossa using a vacuum needle.
Imaging
Ultrasound and magnetic resonance imaging (MRI) can be useful in distinguishing a bursitis, synovitis, or tenosynovitis in the shoulders and hips.[4][11] These tests may be helpful in diagnosing PMR with less characteristic clinical signs and symptoms. Subdeltoid bursitis, bicipital tenosynovitis, glenohumeral synovitis, and/or hip synovitis are characteristic of PMR.[11] Trochanteric bursitis is present in many patients with PMR.[22] Interspinous bursitis may be detected on MRI.[23] The presence of symmetric shoulder and/or hip arthritis in the absence of a bursitis or tenosynovitis would be more suggestive of a systemic arthritis such as rheumatoid arthritis.
Increased uptake of fluorodeoxyglucose F-18 on PET scans can be helpful in identifying inflammation in the joints, bursae, and tenosynovial tissues in the shoulders and large vessels that may be helpful in making a diagnosis of PMR.[24][25] Although this information may be supportive in diagnosing PMR, it remains unclear if such scanning can predict relapses.[17]
Use of this content is subject to our disclaimer