Steroids are the main type of medication to treat polymyositis and dermatomyositis. It may include:
Higher doses of steroid tablets (severe muscle weakness)
Steroid creams (used to treat the affected areas of skin in dermatomyositis)
It causes some side effects such as high blood pressure, weight gain, diabetes, cataracts, and osteoporosis
Disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate, azathioprine, cyclophosphamide or mycophenolate suppress your immune system and help reduce inflammation
Intravenous immunoglobulin therapy: it may be needed in very severe cases of myositis were severe muscle weakness is causing life-threatening breathing or swallowing problems
Biologic therapies which are widely used to treat conditions such as rheumatoid arthritis and psoriatic arthritis