Polymyalgia rheumatica - PMR
Polymyalgia rheumatica (PMR) is an autoimmune disease (vasculitis) that can occur together with giant cell arteritis (RZA). The particular difficulty with PMR is often the diagnosis of only unspecific symptoms and many differential diagnoses (e.g. CPPD). Ultrasound and PET-CT, but also other imaging techniques, have significantly improved and accelerated the diagnosis of both diseases, so that complications such as blindness can be reduced or prevented. Steroids still play an important role in the primary therapy of both diseases. MTX in PMR and tocilizumab in RZA are important therapeutic options. About 20% of patients with PMR have histologically RZA (biopsy of the superficial ramus of the temporal artery) and about 30% show large vessel vasculitis in imaging. Viceversa, about 40-60% of patients with RZA show symptoms of PMR.
Clinical symptoms and characteristics of PMR
- Age of the patients ≥ 50 J.
- New symptoms lasting >2 weeks
- Bilateral pain and stiffness in the neck, shoulders and hips
- Morning stiffness(>45min)
- Systemic symptoms in 40-50% of patients: Fatigue malaise weight loss Subfebrile temperatures/fever
- Increased inflammation parameters (CRP and/or BSR)
- Lack of detection of rheumatoid factors or anti-CCP antibodies
- no involvement of other joints
- Ultrasound: One or both shoulders with subdeltoid bursitis, long biceps tendon synovitis or glenohumeral synovitis AND one or both hips with synovitis or trochanteric bursitis OR Both shoulders with subdeltoid bursitis, long biceps tendon synovitis
Laboratory diagnostics for suspected PMR:
- CRP, BSR, blood count, liver function test and alkaline phosphatase, urine stick analysis; PSA if necessary. TSH
- Rheumatoid factor, anti-CCP-AK ANA,ANCA
- Creatine Kinase
- uric acid, calcium, phosphate
- Protein electrophoresis
- possibly: vitamin D3 glucose tuberculosis test
Differential diagnoses:
- inflammatory diseases (arthritides, e.g. RA, SpA; myopathies/myositides; crystal arthropathies), Important DD due to general symptoms of GPA: Typical are constitutional symptoms that can last prodromally for weeks to months. They correspond to the signs of systemic inflammation, i.e. fever, malaise, loss of appetite and weight; not infrequently, however, patients also complain of migratory joint pain and muscle pain (cave initial manifestation under the image of the polymyalgic syndrome).
- degenerative diseases (arthrosis, frozen shoulder/adhesive capsulitis, periarthropathies)
- Endocrinopathies (hypothyroidism)
- Infections (viral, bacterial)
- paraneoplastic appearance of PMR
Recommendations for the therapy of PMR:
- Oral glucocorticoids in a single morning dose
- Usually between 15 and 20 (25) mg prednisone equivalent
- No initial doses <7.5 mg/day or >30 mg/day
- Continuous reduction under clinical/laboratory chemical control E.g.
- Oral dose of 10 mg/day prednisone equivalent after 4-8 weeks Afterwards reduction approx. 1 mg every 4 weeks until discontinuation
- In case of recurrence, increase to the previous dose and reduction after 4-8 weeks
- Consider early administration of methotrexate
- No biologics recommended (data available for tocilizumab not sufficient)
- treatment with TNF-alpha-inhibitors is explicitly not recommended
https://www.awmf.org/uploads/tx_szleitlinien/060-006l_S3_Polymyalgia-rheumatica_2018-05.pdf