Overview

Myositis Overview

Myositis is a term for inflammation of your muscles. It is a rare condition caused by your immune system mistakenly attacking your own muscles, leading to long-term inflammation.

The inflammation can cause:

• Muscle fatigue or weakness
• Muscle or joint pain

Types of Myositis

There are different types of myositis, including:

• Dermatomyositis: Causes a skin rash and muscle weakness.
• Inflammatory Myopathy, formerly known as polymyositis: Causes inflammation in muscle groups near the center of your body, such as your shoulders, hips, abdomen, upper arms and chest. This causes weakness on both sides of your body. It can also affect your lungs.
• Inclusion body myositis: A degenerative muscle disease that causes weakness in areas such as your legs, arms, fingers and wrists. It can also affect the muscles in your throat that help you swallow.
• Anti-synthetase syndrome: Causes inflammation throughout your body that can affect your muscles, joints, lungs, skin and blood vessels. People with this syndrome typically have symptoms of other conditions, such as interstitial lung disease, polyarthritis, Raynaud’s phenomenon, or fever.
• Immune-mediated necrotizing myopathy: Kills muscle cells (necrosis) and leads to muscle weakness on both sides of the body in areas such as the hips, thighs, upper arms, shoulders and neck.
• Overlap syndromes: Occurs when someone is diagnosed with two or more autoimmune diseases. Some common diseases that overlap myositis are lupus, scleroderma, rheumatoid arthritis and Sjögren's syndrome.

To schedule a visit at the Northwestern Medicine Myositis Clinic, please call 312.696.7950.