Table of ContentsView AllTable of ContentsTypes and SymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Types and Symptoms
Causes
Diagnosis
Treatment
Myositis literally means “muscle inflammation.” The term myositis also describes the group of conditions—calledinflammatory myopathies—that cause chronic muscle inflammation, damage, weakness, and (sometimes) pain.
Because of its rarity, a diagnosis of myositis isn’t always easy to make, and the cause of it is not always known. According to The Myositis Association, all forms of myositis affect an estimated 50,000 to 75,000 Americans.While the condition has no cure, it is treatable.
Here is what you need to know about myositis, including the types, symptoms, causes, and treatment.
Jay Yuno / Getty Images
Myositis takes many forms, including polymyositis, dermatomyositis, inclusion body myositis, immune-mediated necrotizing myopathy, antisynthetase syndrome, and juvenile myositis. There are other forms of myositis, but they are considered much more rare.
Many types of myositis areautoimmune diseases, conditions where the body’s immune system attacks and damages its own tissues.
Polymyositis
Polymyositiscauses muscle weakness on both sides of the body. Having polymyositis makes it hard to climb steps, get up from a seated position, reach overhead, and lift. It can affect anyone of any age, but is more common in adults ages 31 to 60 years of age, women, and people of color.
Symptoms of polymyositis develop gradually over weeks or months, and may include:
Dermatomyositis
Dermatomyositis(DM) is easier to diagnose than other types of myositis. It is distinguishable because of the purple-red, patchy-like rashes it causes. These rashes appear on the eyelids, face, chest, neck, and back.
Rashes may also appear on the knuckles, toes, knees, and elbows. Muscle weakness often follows.
This type of myositis can affect anyone of any age, but it is most common in adults in their late 40s to early 60s and in children ages 5 to 15.
Other symptoms of DM include:
Causes of Muscle Pain
Inclusion Body Myositis
Inclusion body myositis(IBM) affects more men than women, and most people who develop this condition are over age 50.Initial symptoms of IBM include muscle weakness in the wrists and fingers. IBM may also cause weakness in the thighs, but is more prominent in the smaller muscles.
This type of myositis is often asymmetrical, meaning it affects one side of the body more than the other.
Causes of IBM are not understood, but researchers believe a combination of genetic, immune-related, and environmental factors are involved in its development.Some people have certain genes that predispose them to the condition, but IBM is not necessarily inherited.
In addition to muscle weakness, IBM may cause:
Immune-Mediated Nercotizing Myopathy
Symptoms of IMNM are similar to those of other types of myositis and may include:
What makes IMNM different from other types of myositis is that people with this type have less inflammation and increased evidence ofnecrosis. Researchers have been unable to determine potential causes, but think certain autoantibodies play a role in its development.
Autoantibodies are proteins produced in the immune system that mistakenly target the body’s own tissues. Much like other types of myositis, there is no cure for IMNM, but the condition is treatable.
Antisynthetase Syndrome
Antisynthetase syndrome is known for causing muscle and joint inflammation, interstitial lung disease (ILD), thickening and cracking of the hands (mechanic’s hands), andRaynaud’s syndrome.
Interstitial lung disease is usually one of the first or only symptoms of this type of myositis. ILD is an umbrella term for a group of disorders that cause fibrosis—scarring of the lungs.
Fibrosis causes stiffness in the lungs that affects breathing.Raynaud’s syndrome causes fingers or toes to be discolored after being exposed to temperature changes or emotional events.
The exact cause of antisynthetase syndrome is unknown, but the production of certain autoantibodies are believed to be linked to its development. The average age for disease onset is around 50 years, and the condition is more common in women.
Juvenile Myositis
Juvenile myositis (JM) affects children under 18. According to The Myositis Association, JM affects two to four out of every one million children.Girls are more likely to develop JM.
In addition to muscle weakness, JM may cause:
Similar to other types of myositis, there is no known cause or cure for JM. Treatment can successfully manage symptoms of the condition.
Growing Pains in Children and When to Be Concerned
Any condition that causes muscle inflammation can lead to myositis. Causes may include inflammatory conditions, infections, medications and drugs, injury, or a condition called rhabdomyolysis which causes muscle breakdown.
Know the Signs of Inflammation
Make an appointment to see your healthcare provider if you experience ongoing muscle weakness or a rash on the face or knuckles that doesn’t go away.
Other reasons to contact a practitioner are:
Testing
A diagnosis of myositis is often difficult to make because the condition is so rare and also because symptoms are common in other conditions. If a healthcare provider suspects myositis, the following tests might be done:
Diagnosing myositis can be a long process. This is because muscle weakness and pain are symptoms of a number of conditions. In addition, other causes of muscle pain, stiffness, and weakness are more common than myositis.
Currently, there is no cure for myositis. However, the disease can be managed, and medicinal treatment is helpful for reducing inflammation and keeping muscle weakness from getting worse. Your healthcare provider will also recommend lifestyle changes to help improve strength.
Medicine
Medicinal treatment for myositis involves three types of drugs: corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and biologic therapies.
Corticosteroids, such as prednisone, are a first-line treatment for myositis.These drugs suppress theimmune systemto slow down the attack on healthy tissues and treat skin rash.
Treatment with corticosteroids may reduce muscle inflammation and pain, and increase muscle strength. Dosage varies from patient to patient, but healthcare providers prescribe high doses early on and decrease dosage as symptoms improve.
NSAIDs, such as aspirin or ibuprofen, can help reduce inflammation in muscles and surrounding tissues.
If your healthcare provider prescribes a biologic, they believe the benefit of taking the drug outweighs the risk of side effects.
Lifestyle
Exercise andphysical therapy, rest, nutrition, and stress reduction may also help to reduce myositis symptoms.
An Overview of Physical Therapy
A Word From Verywell
The outlook for most types of myositis can be good with proper treatment. But if left untreated, myositis can result in disability or death. That is why it is important to manage symptoms and stay on top of your healthcare provider’s treatment plan.
It is possible to experience remission and periods of low disease activity with proper and continued treatment.
Myalgia Causes and Treatment
14 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Myositis Association.About myositis.Myositis Support and Understanding Association.Myositis: the basics.Genetic and Rare Diseases Information Center.Polymyositis.Genetic and Rare Diseases Information Center.Dermatomyositis.Genetic and Rare Diseases Information Center.Inclusion body myositis.Dimachkie MM, Barohn RJ.Inclusion body myositis.Semin Neurol. 2012;32(3):237-245. doi:10.1055/s-0032-1329197Babu SS, Khanna L, Saran RK, Mittal G, Peter S, Sebastian I.Necrotizing autoimmune myopathy.Ann Indian Acad Neurol. 2016;19(2):288-290. doi:10.4103/0972-2327.176864Khan NAJ, Shaza K, Ullah S, Malik MU, Makhoul S.Necrotizing autoimmune myopathy: a rare variant of idiopathic inflammatory myopathies.J Investig Med High Impact Case Rep. 2017;5(2):2324709617709031. doi:10.1177/2324709617709031Genetic and Rare Diseases Information Center.Antisynthetase syndrome.American Lung Institute.Interstitial lung disease (ILD).The Myositis Association.Juvenile myositis.Valiyil R, Christopher-Stine L.Drug-related myopathies of which the clinician should be aware.Curr Rheumatol Rep. 2010;12(3):213–220. doi:10.1007/s11926-010-0104-3Torres PA, Helmstetter JA, Kaye AM, Kaye AD.Rhabdomyolysis: pathogenesis, diagnosis, and treatment.Ochsner J. 15(1):58-69.The Myositis Association.Corticosteroids.Additional ReadingNational Institute of Neurological Disorders and Stroke.Inflammatory myopathies information page.
14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Myositis Association.About myositis.Myositis Support and Understanding Association.Myositis: the basics.Genetic and Rare Diseases Information Center.Polymyositis.Genetic and Rare Diseases Information Center.Dermatomyositis.Genetic and Rare Diseases Information Center.Inclusion body myositis.Dimachkie MM, Barohn RJ.Inclusion body myositis.Semin Neurol. 2012;32(3):237-245. doi:10.1055/s-0032-1329197Babu SS, Khanna L, Saran RK, Mittal G, Peter S, Sebastian I.Necrotizing autoimmune myopathy.Ann Indian Acad Neurol. 2016;19(2):288-290. doi:10.4103/0972-2327.176864Khan NAJ, Shaza K, Ullah S, Malik MU, Makhoul S.Necrotizing autoimmune myopathy: a rare variant of idiopathic inflammatory myopathies.J Investig Med High Impact Case Rep. 2017;5(2):2324709617709031. doi:10.1177/2324709617709031Genetic and Rare Diseases Information Center.Antisynthetase syndrome.American Lung Institute.Interstitial lung disease (ILD).The Myositis Association.Juvenile myositis.Valiyil R, Christopher-Stine L.Drug-related myopathies of which the clinician should be aware.Curr Rheumatol Rep. 2010;12(3):213–220. doi:10.1007/s11926-010-0104-3Torres PA, Helmstetter JA, Kaye AM, Kaye AD.Rhabdomyolysis: pathogenesis, diagnosis, and treatment.Ochsner J. 15(1):58-69.The Myositis Association.Corticosteroids.Additional ReadingNational Institute of Neurological Disorders and Stroke.Inflammatory myopathies information page.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
The Myositis Association.About myositis.Myositis Support and Understanding Association.Myositis: the basics.Genetic and Rare Diseases Information Center.Polymyositis.Genetic and Rare Diseases Information Center.Dermatomyositis.Genetic and Rare Diseases Information Center.Inclusion body myositis.Dimachkie MM, Barohn RJ.Inclusion body myositis.Semin Neurol. 2012;32(3):237-245. doi:10.1055/s-0032-1329197Babu SS, Khanna L, Saran RK, Mittal G, Peter S, Sebastian I.Necrotizing autoimmune myopathy.Ann Indian Acad Neurol. 2016;19(2):288-290. doi:10.4103/0972-2327.176864Khan NAJ, Shaza K, Ullah S, Malik MU, Makhoul S.Necrotizing autoimmune myopathy: a rare variant of idiopathic inflammatory myopathies.J Investig Med High Impact Case Rep. 2017;5(2):2324709617709031. doi:10.1177/2324709617709031Genetic and Rare Diseases Information Center.Antisynthetase syndrome.American Lung Institute.Interstitial lung disease (ILD).The Myositis Association.Juvenile myositis.Valiyil R, Christopher-Stine L.Drug-related myopathies of which the clinician should be aware.Curr Rheumatol Rep. 2010;12(3):213–220. doi:10.1007/s11926-010-0104-3Torres PA, Helmstetter JA, Kaye AM, Kaye AD.Rhabdomyolysis: pathogenesis, diagnosis, and treatment.Ochsner J. 15(1):58-69.The Myositis Association.Corticosteroids.
The Myositis Association.About myositis.
Myositis Support and Understanding Association.Myositis: the basics.
Genetic and Rare Diseases Information Center.Polymyositis.
Genetic and Rare Diseases Information Center.Dermatomyositis.
Genetic and Rare Diseases Information Center.Inclusion body myositis.
Dimachkie MM, Barohn RJ.Inclusion body myositis.Semin Neurol. 2012;32(3):237-245. doi:10.1055/s-0032-1329197
Babu SS, Khanna L, Saran RK, Mittal G, Peter S, Sebastian I.Necrotizing autoimmune myopathy.Ann Indian Acad Neurol. 2016;19(2):288-290. doi:10.4103/0972-2327.176864
Khan NAJ, Shaza K, Ullah S, Malik MU, Makhoul S.Necrotizing autoimmune myopathy: a rare variant of idiopathic inflammatory myopathies.J Investig Med High Impact Case Rep. 2017;5(2):2324709617709031. doi:10.1177/2324709617709031
Genetic and Rare Diseases Information Center.Antisynthetase syndrome.
American Lung Institute.Interstitial lung disease (ILD).
The Myositis Association.Juvenile myositis.
Valiyil R, Christopher-Stine L.Drug-related myopathies of which the clinician should be aware.Curr Rheumatol Rep. 2010;12(3):213–220. doi:10.1007/s11926-010-0104-3
Torres PA, Helmstetter JA, Kaye AM, Kaye AD.Rhabdomyolysis: pathogenesis, diagnosis, and treatment.Ochsner J. 15(1):58-69.
The Myositis Association.Corticosteroids.
National Institute of Neurological Disorders and Stroke.Inflammatory myopathies information page.
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