How to Diagnose Myositis | Routine Tests & More

Inflammatory Myositis - Diagnosis

Due to the many different forms of myositis and similarities to other muscular and nerve diseases, it may take a few visits to the doctor before the condition can be diagnosed.

After a careful physical examination, the doctor will order other tests to confirm the diagnosis. Such tests may include:

Routine tests like a full blood count, erythrocyte sedimentation rate (ESR), and c-reactive protein (CRP) test

Blood tests for muscle enzymes and auto-antibodies. Muscle enzyme levels (usually raised initially) are useful for monitoring progress and response to treatment

Electromyogram (EMG): This is a test that measures the electrical activity of muscles. In patients with myositis the EMG would be abnormal

Muscle biopsy: The doctor takes a sample of the affected muscle to be checked under the microscope. The procedure is done under local anaesthesia

X-ray of the chest: To investigate for lung cancer and lung involvement associated with myositis

Magnetic Resonance Imaging (MRI): This painless scan can identify abnormal muscles and can be used to locate the best site for a biopsy and to monitor the progress of the disorder