Polymyositis

This code represents polymyositis, a chronic, inflammatory autoimmune disease characterized by progressive symmetrical muscle weakness, primarily affecting the proximal muscles. It involves inflammation of the skeletal muscles, leading to muscle fiber damage and degeneration.

Use this code for documented cases of polymyositis confirmed by clinical presentation, elevated muscle enzymes (e.g., CK, aldolase), electromyography (EMG) findings, and muscle biopsy. It is appropriate when the physician explicitly diagnoses polymyositis as the primary or secondary condition.

• Differentiate from dermatomyositis (which includes skin involvement) and inclusion body myositis.
• Look for documentation of specific muscle groups affected and the chronicity of the condition.
• Consider sequencing with codes for associated systemic conditions or complications, such as interstitial lung disease or dysphagia.