The answer is D: a, b, and c
The differences between PMR and polymyositis on clinical examination are as follows:
- There is marked weakness associated with proximal muscle pain in polymyositis
- There is often marked muscle tenderness (versus joint pain in PMR) associated with the proximal muscle pain in polymyositis
- Laboratory examination reveals elevated muscle enzymes only in polymyositis
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Polymyositis Pearls
Autoimmune-mediated inflammatory destruction of muscles leading to muscle weakness
- Patients with polymyositis experience proximal symmetric (bilateral) muscle weakness
- The shoulders and hips are the parts of the body most commonly affected by polymyositis
- Early fatigue while walking and inability to rise from a seated position
Diagnosis
- The three autoantibodies anti-Jo-1, anti-SRP, and anti-Mi-2, are associated with polymyositis
- Creatine kinase levels are increased in polymyositis
- Electromyography can detect regions of dead muscle cells
- Muscle biopsy can show endomysial inflammation and various stages of necrosis
Treatment
- Initial treatment of polymyositis involves suppressing the immune response with corticosteroids
- Methotrexate is used for long-term immunosuppressive therapy in polymyositis