Polymyalgia Rheumatica Diagnosis and Treatment

Diagnostic Workup

The initial workup for suspected polymyalgia rheumatica should include a comprehensive laboratory assessment to exclude mimicking conditions, followed by treatment with glucocorticoids at a dose of 12.5-25 mg prednisone equivalent daily, as recommended by the European League Against Rheumatism 1, 2, 3
Obtain rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies (ACPA) to exclude rheumatoid arthritis, according to the American College of Rheumatology 1, 2
Measure inflammatory markers: C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR) - typically elevated in PMR, as noted by the European League Against Rheumatism 1, 3

Evaluate for hypertension, diabetes, glucose intolerance, cardiovascular disease, as recommended by the American Heart Association 1, 4
Screen for dyslipidemia, peptic ulcer disease, osteoporosis, according to the National Osteoporosis Foundation 1

Start with prednisone 12.5-25 mg daily, as recommended by the European League Against Rheumatism 1, 4
Higher initial doses within this range for patients with high relapse risk and low adverse event risk, according to the American College of Rheumatology 4

Every 4-8 weeks during the first year of treatment, as recommended by the European League Against Rheumatism 1, 5

Consider specialist referral for atypical presentations (peripheral arthritis, systemic symptoms, low inflammatory markers, age <60 years), according to the American College of Rheumatology 3
Female sex may be associated with higher risk of glucocorticoid side effects, as noted by the European League Against Rheumatism 1, 3
Risk factors for relapse include female sex, high ESR (>40 mm/hr), and peripheral inflammatory arthritis, according to the American College of Rheumatology 1

When evaluating suspected PMR, a complete rheumatologic history and examination of all peripheral joints should be performed, but pelvic girdle involvement is not mandatory for diagnosis, as recommended by the American College of Rheumatology 6

Some patients may develop PMR-like syndromes (particularly in the context of immune checkpoint inhibitor therapy) that may not follow the classic distribution pattern, according to the European League Against Rheumatism 7
In immune checkpoint inhibitor-induced PMR-like syndromes, patients can develop severe myalgia in their proximal upper extremities resembling PMR, sometimes without significant lower extremity involvement, as reported by the American Society of Clinical Oncology 8

When PMR presents without pelvic girdle pain, it's essential to consider other conditions that can cause isolated shoulder pain, such as bilateral shoulder capsulitis, rotator cuff tendinitis, and other soft tissue rheumatic disorders, as suggested by the American College of Rheumatology 6, 8
Inflammatory myositis should be considered in the differential diagnosis, as it can mimic PMR but typically presents with true weakness rather than just pain, according to the American College of Rheumatology 8