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• Symptoms
• Diagnosis and Tests
• Treatments and Therapies

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Summary

Myositis means inflammation of the muscles that you use to move your body. An injury, infection, or autoimmune disease can cause it. Two specific kinds are polymyositis and dermatomyositis. Polymyositis causes muscle weakness, usually in the muscles closest to the trunk of your body. Dermatomyositis causes muscle weakness, plus a skin rash.

Other symptoms of myositis may include:

• Fatigue after walking or standing
• Tripping or falling
• Trouble swallowing or breathing

Doctors may use a physical exam, lab tests, imaging tests and a muscle biopsy to diagnose myositis. There is no cure for these diseases, but you can treat the symptoms. Polymyositis and dermatomyositis are first treated with high doses of a corticosteroid. Other options include medications, physical therapy, exercise, heat therapy, assistive devices, and rest.

NIH: National Institute of Neurological Disorders and Stroke

Start Here

• Dermatomyositis (Genetic and Rare Diseases Information Center)
• Metabolic Myopathies (American College of Rheumatology) Also in Spanish

Symptoms

• Dermatomyositis: Signs and Symptoms (Muscular Dystrophy Association)

Diagnosis and Tests

• ANA (Antinuclear Antibody) Test (National Library of Medicine) Also in Spanish
• Dermatomyositis: Diagnosis (Muscular Dystrophy Association)
• Electromyography (EMG) and Nerve Conduction Studies (National Library of Medicine) Also in Spanish
• Inclusion-Body Myositis: Diagnosis (Muscular Dystrophy Association)
• Polymyositis: Diagnosis (Muscular Dystrophy Association)

Treatments and Therapies

• Dermatomysitis: Medical Management (Muscular Dystrophy Association)
• Polymyositis (PM): Medical Management (Muscular Dystrophy Association)

Specifics

• Dermatomyositis (DM) (American Osteopathic College of Dermatology)
• Inclusion Body Myositis (National Institute of Neurological Disorders and Stroke)
• Inflammatory Myopathies (National Institute of Neurological Disorders and Stroke)
• Polymyositis (Mayo Foundation for Medical Education and Research) Also in Spanish

Genetics

• Idiopathic inflammatory myopathy: MedlinePlus Genetics (National Library of Medicine)

Clinical Trials

• ClinicalTrials.gov: Dermatomyositis (National Institutes of Health)
• ClinicalTrials.gov: Myositis (National Institutes of Health)
• ClinicalTrials.gov: Polymyositis (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Clinical impact of pneumomediastinum in patients with myositis-associated interstitial lung disease.
• Article: Integrating Machine Learning into Myositis Research: a Systematic Review.
• Article: N-glycosylation patterns of plasma immunoglobulin G in anti-synthetase syndrome disease.
• Myositis -- see more articles

Find an Expert

• Find a Rheumatologist (American College of Rheumatology)
• National Institute of Arthritis and Musculoskeletal and Skin Diseases Also in Spanish
• National Institute of Neurological Disorders and Stroke

Children

• Dermatomyositis (Juvenile) (American College of Rheumatology) Also in Spanish
• Juvenile Dermatomyositis (For Parents) (Nemours Foundation) Also in Spanish

Patient Handouts

• Creatine phosphokinase test (Medical Encyclopedia) Also in Spanish
• Dermatomyositis (Medical Encyclopedia) Also in Spanish
• Polymyositis - adult (Medical Encyclopedia) Also in Spanish