Polymyositis is a generalized systemic chronic inflammation of the muscles that causes muscle pain and wasting of the affected muscles. As a result, the patient loses strength in the muscles, particularly those in the pelvis.
In order to establish a definitive diagnosis, a patient must meet four criteria:
- Elevated creatine kinase levels
- A complete medical history and physical examination to rule out other causes
- An EMG
- A muscle biopsy
Once confirmed, steroids are indicated. Patients are generally started on prednisone and are moved to more powerful immunosuppressants if they do not improved. Immunoglobulin and physiotherapy can also be helpful.