From the Guidelines
Myositis is an inflammatory muscle disease that requires prompt recognition and treatment to prevent severe complications, and the most recent evidence suggests that high-dose systemic glucocorticoids, such as prednisone at 1 mg/kg/day, should be initiated as first-line therapy, with consideration of intravenous immunoglobulin (IVIG) and other immunosuppressants for severe or refractory cases 1. The symptoms of myositis include progressive muscle weakness, especially in the shoulders, hips, and neck, muscle pain that worsens with activity, fatigue, skin rashes in dermatomyositis, joint pain, and fever. Some patients may experience difficulty rising from chairs, climbing stairs, or lifting objects. Treatment options for myositis typically involve corticosteroids like prednisone, with immunosuppressants such as methotrexate, azathioprine, or mycophenolate mofetil added as steroid-sparing agents. For severe or refractory cases, IVIG at 2 g/kg divided over 2-5 days may be used, and physical therapy is crucial to maintain muscle strength and prevent contractures. Patients should also be monitored for complications like interstitial lung disease, cardiac involvement, and malignancy, particularly in dermatomyositis. The inflammatory nature of myositis stems from autoimmune mechanisms, where the body's immune system attacks muscle tissue, leading to inflammation and damage, which explains why immunosuppressive therapies are the mainstay of treatment. Key considerations in managing myositis include:
- Prompt recognition and early management to prevent severe complications
- Use of high-dose systemic glucocorticoids as first-line therapy
- Consideration of IVIG and other immunosuppressants for severe or refractory cases
- Monitoring for complications like interstitial lung disease, cardiac involvement, and malignancy
- Physical therapy to maintain muscle strength and prevent contractures. According to the most recent evidence, the management of myositis should prioritize the use of high-dose systemic glucocorticoids, with consideration of IVIG and other immunosuppressants for severe or refractory cases, as outlined in the guidelines 1.
From the Research
Symptoms of Myositis
- Muscle weakness is a common symptom of myositis, which can be progressive and affect various parts of the body 2
- Extra-muscular features may vary considerably between patients and are frequently non-specific, making diagnosis challenging 2
- Myositis can cause significant morbidity and may be fatal, mainly due to cancer and interstitial lung disease 2
Treatment Options for Myositis
- Corticosteroids, such as oral high-dose prednisone, are often used to treat myositis, and may be combined with immunosuppressants like azathioprine or methotrexate 3, 4
- Intravenous immunoglobulin (IVIg) can be used as add-on therapy for patients not adequately controlled with steroids or immunosuppressive agents 3, 4, 5
- Other treatment options include rituximab, mycophenolate mofetil, tacrolimus, and cyclophosphamide, which may be effective in patients with refractory myositis 3, 4, 5
- Novel approaches, such as biologic agents, stem-cell transplantation, and gene therapy, are being explored for the treatment of myositis 5
- Corticosteroid treatment may be effective in some patients with granulomatous myositis, which can mimic inclusion body myositis 6