Dermatomyositis
Dermatomyositis is a disease that involves muscle inflammation and a skin rash. Polymyositis is a similar inflammatory condition that also involves muscle weakness, swelling, tenderness, and tissue damage but no skin rash. Both are part of a larger group of diseases called myopathies, more specifically inflammatory myopathies.
Polymyositis
Polymyositis and dermatomyositis are rare inflammatory diseases. (The condition is called dermatomyositis when it involves the skin. ) These disease...
Read Article Now Book Mark ArticleCauses
The cause of dermatomyositis is unknown. Experts think it may be due to a viral infection of the muscles or a problem with the body's immune system. It may also occur in people who have cancer in the abdomen, lung, or other parts of the body.
Anyone can develop this condition. It most often occurs in children age 5 to 15 and adults age 40 to 60. It affects women more often than men.
Symptoms
Symptoms may include:
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Muscle weakness, stiffness, or soreness
Muscle weakness
Weakness is reduced strength in one or more muscles.
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- Purple color to the upper eyelids
- Purple-red skin rash
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Shortness of breath
Shortness of breath
Breathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough air
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The muscle weakness may come on suddenly or develop slowly over weeks or months. You may have trouble raising your arms over your head, getting up from a sitting position, and climbing stairs.
The rash may appear on your face, knuckles, neck, shoulders, upper chest, and back.
Exams and Tests
The health care provider will do a physical exam. Tests may include:
- Bloods test to check levels of muscle enzymes called creatine phosphokinase and aldolase
Aldolase
Aldolase is a protein (called an enzyme) that helps break down certain sugars to produce energy. It is found in high amount in muscle and liver tiss...
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Electrocardiogram (ECG)
Electrocardiogram (ECG)
An electrocardiogram (ECG) is a test that records the electrical activity of the heart.
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Electromyography (EMG)
Electromyography
Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.
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Muscle biopsy
Muscle biopsy
A muscle biopsy is the removal of a small piece of muscle tissue for examination.
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Skin biopsy
Skin biopsy
A skin lesion biopsy is when a small amount of skin is removed so it can be examined under a microscope. The skin is tested to look for skin conditi...
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- Chest x-ray and CT scan of the chest
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Lung function tests
Lung function tests
Pulmonary function tests are a group of tests that measure breathing and how well the lungs are functioning.
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Swallowing study
Swallowing study
Esophageal manometry is a test to measure how well the esophagus is working.
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Treatment
The main treatment is the use of corticosteroid medicines. The dose of medicine is slowly tapered off as muscle strength improves. This takes about 4 to 6 weeks. You may stay on a low dose of a corticosteroid medicine after that.
Medicines to suppress the immune system may be used to replace the corticosteroids. These drugs may include azathioprine, methotrexate or mycophenolate.
Treatments that may be tried when disease that remains active in spite of these medicines are:
- Intravenous gamma globulin
- Biologic drugs
When your muscles get stronger, your provider may tell you to slowly cut back on your doses. Many people with this condition must take a medicine called prednisone for the rest of their lives.
If a tumor is causing the condition, the muscle weakness and rash may get better when the tumor is removed.
Outlook (Prognosis)
It is important to be followed by a health care provider when you have dermatomyositis. Severe illness can lead to disability and can sometimes result in death.
Symptoms may go away completely in some people, such as children.
The condition may be fatal in adults due to:
- Severe muscle weakness
- Malnutrition
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Pneumonia
Pneumonia
Pneumonia is a breathing (respiratory) condition in which there is an infection of the lung. This article covers community-acquired pneumonia (CAP). ...
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The major causes of death with this condition are cancer and lung disease.
People with lung disease with the anti-MDA-5 antibody have a poor prognosis in spite of current treatment.
Possible Complications
Complications may include:
- Lung disease
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Acute renal failure
Acute renal failure
Acute kidney failure is the rapid (less than 2 days) loss of your kidneys' ability to remove waste and help balance fluids and electrolytes in your b...
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Malignancy
The term "malignancy" refers to the presence of cancerous cells that have the ability to spread to other sites in the body (metastasize) or to invade...
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Inflammation of the heart
Inflammation of the heart
Pericarditis is a condition in which the sac-like covering around the heart (pericardium) becomes inflamed.
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When to Contact a Medical Professional
Contact your provider if you have muscle weakness or other symptoms of this condition.
References
Aggarwal R, Rider LG, Ruperto N, et al. 2016 American College of Rheumatology/European League against rheumatism criteria for minimal, moderate, and major clinical response in adult dermatomyositis and polymyositis: An International Myositis Assessment and Clinical Studies Group/Paediatric Rheumatology International Trials Organisation Collaborative Initiative. Arthritis Rheumatol. 2017;69(5):898-910. PMID: 28382787 pubmed.ncbi.nlm.nih.gov/28382787/.
Dalakas MC. Inflammatory muscle diseases. N Engl J Med. 2015;373(4):393-394. PMID: 26200989 pubmed.ncbi.nlm.nih.gov/26200989/.
Nagaraju K, Aggarwal R, Lundberg IE. Inflammatory diseases of muscle and other myopathies. In: Firestein GS, Budd RC, Gabriel SE, Koretzky GA, McInnes IB, O'Dell JR, eds. Firestein & Kelley's Textbook of Rheumatology. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 90.
National Organization for Rare Disorders website. Dermatomyositis. rarediseases.org/rare-diseases/dermatomyositis/. Updated 2018. Accessed March 3, 2023.
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Dermatomyositis - Gottron papule - illustration
Red, thickened, scaly skin over the knuckles (Gottron sign) associated with dermatomyositis, an autoimmune disease of the skin and muscles.
Dermatomyositis - Gottron papule
illustration
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Dermatomyositis - Gottron's papules on the hand - illustration
This violet-colored inflammation (erythema) over the knuckles is caused by Dermatomyositis. Other skin conditions produce more redness, while the color of this lesion is violet. There may also be inflammation in the muscle tissue.
Dermatomyositis - Gottron's papules on the hand
illustration
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Dermatomyositis - heliotrope eyelids - illustration
This photograph demonstrates the sign heliotrope eyelids in which the eyelids develop a brown (violaceous - rather than red) color. Heliotrope eyelids and Gottron's papules on the knuckles are characteristic findings in dermatomyositis.
Dermatomyositis - heliotrope eyelids
illustration
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Dermatomyositis on the legs - illustration
The appearance of purple (violaceous) plaques on the knees may be associated with dermatomyositis. Typically, most lesions associated with other diseases are red (erythematous).
Dermatomyositis on the legs
illustration
-
Dermatomyositis - Gottron papule - illustration
This is Gottron sign, seen in dermatomyositis (an inflammatory disease of the muscles and skin). Violet-colored inflammation over the knuckles is an important diagnostic finding in dermatomyositis, since other skin conditions produce more redness.
Dermatomyositis - Gottron papule
illustration
-
Dermatomyositis - heliotrope rash on the face - illustration
Dermatomyositis, a connective tissue disease, typically produces a reddish-purple (violaceous) rash. The rash is named after the tendency of plants to grow toward the sun (heliotropic) and is characteristic of dermatomyositis.
Dermatomyositis - heliotrope rash on the face
illustration
-
Dermatomyositis - Gottron papule - illustration
Red, thickened, scaly skin over the knuckles (Gottron sign) associated with dermatomyositis, an autoimmune disease of the skin and muscles.
Dermatomyositis - Gottron papule
illustration
-
Dermatomyositis - Gottron's papules on the hand - illustration
This violet-colored inflammation (erythema) over the knuckles is caused by Dermatomyositis. Other skin conditions produce more redness, while the color of this lesion is violet. There may also be inflammation in the muscle tissue.
Dermatomyositis - Gottron's papules on the hand
illustration
-
Dermatomyositis - heliotrope eyelids - illustration
This photograph demonstrates the sign heliotrope eyelids in which the eyelids develop a brown (violaceous - rather than red) color. Heliotrope eyelids and Gottron's papules on the knuckles are characteristic findings in dermatomyositis.
Dermatomyositis - heliotrope eyelids
illustration
-
Dermatomyositis on the legs - illustration
The appearance of purple (violaceous) plaques on the knees may be associated with dermatomyositis. Typically, most lesions associated with other diseases are red (erythematous).
Dermatomyositis on the legs
illustration
-
Dermatomyositis - Gottron papule - illustration
This is Gottron sign, seen in dermatomyositis (an inflammatory disease of the muscles and skin). Violet-colored inflammation over the knuckles is an important diagnostic finding in dermatomyositis, since other skin conditions produce more redness.
Dermatomyositis - Gottron papule
illustration
-
Dermatomyositis - heliotrope rash on the face - illustration
Dermatomyositis, a connective tissue disease, typically produces a reddish-purple (violaceous) rash. The rash is named after the tendency of plants to grow toward the sun (heliotropic) and is characteristic of dermatomyositis.
Dermatomyositis - heliotrope rash on the face
illustration
Review Date: 1/25/2023
Reviewed By: Neil J. Gonter, MD, Assistant Professor of Medicine, Columbia University, NY and private practice specializing in Rheumatology at Rheumatology Associates of North Jersey, Teaneck, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.