polymyositis

Full Definition

Polymyositis is an idiopathic inflammatory myopathy characterized by chronic muscle inflammation, proximal muscle weakness, and elevated serum muscle enzymes. Unlike dermatomyositis, it lacks characteristic skin changes. Diagnosis requires muscle biopsy showing inflammatory infiltrates, elevated creatine kinase, and characteristic EMG changes. The condition responds to immunosuppressive therapy.

Usage

Usage note: Distinguish from dermatomyositis, which includes characteristic skin manifestations.

In Context

• "Polymyositis was diagnosed based on proximal weakness, elevated CK, and muscle biopsy findings." — Clinical summary
• "Corticosteroid treatment improved strength in the patient with polymyositis." — Treatment response