Written by Dr.Yazeedallah Nasr
Polymyositisis an uncommon connective tissue disease. It is a type of inflammatory myopathy, which is characterized by muscle inflammation and weakness which occurs at any age, but it mostly affects adults sometime between their 30s and 50s. It’s more common in blacks than in whites, and women are affected more often than men.
Infections caused by bacteria, parasites or viruses, certain people may have a genetic susceptibility to the disease. Initial injury causes release of muscle auto antigen, which is subsequently taken up by macrophages and presented to CD4+ TH cells. Activated TH cells synthesize IFN-γ that stimulate further macrophages and further inflammatory mediator release like IL-1 and TNF-α.
Signs and symptoms:
- Difficulty of speaking
- Mild joint or muscle tenderness
- Shortness of breath
- Aspiration and pneumonia
- Breathing problems
- Calcium deposits (calcinosis)
- Associated conditions as Raynaud’s phenomenon
Tests and diagnosis:
- Imaging tests (MRI)
- Muscle tests (Electromyography-Muscle biopsy).
- Blood tests and blood analysis that show increase in creatine kinase and aldolase that indicates muscle damage
- High-dose steroids are the treatment of choice
- Antibody therapy
- Intravenous immunoglobulin (IVIg)
- Specialized exercise therapy may supplement treatment to enhance quality of life