Dermatomyositis


Updated February 24, 2020

This article was scientifically reviewed by YourDNA

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A list of references is also included at the bottom of this article.

What is Dermatomyositis?

Dermatomyositis (dur-muh-toe-my-uh-SY-tis) is a rare inflammatory disease characterized by the onset of a rash followed by muscle weakness and inflammation. Blood vessels are also impacted to some degree as well.

It affects females almost twice as often as males, and both children and adults can be stricken. Children are most commonly affected between 5 and 15 years old 1.

What's in this Guide?

Disclaimer: Before You Read

It is important to know that your genes are not your destiny. There are various environmental and genetic factors working together to shape you. No matter your genetic makeup, maintain ideal blood pressure and glucose levels, avoid harmful alcohol intake, exercise regularly, get regular sleep. And for goodness sake, don't smoke.

Genetics is a quickly changing topic. Read More...

Adults will usually experience symptoms in their late 40s to early 60s. However, cases have been reported in people up to 80 years old.

Although there is no cure for dermatomyositis, the condition can go into periods of remission. Treatment can also lessen symptoms by clearing the skin rash and helping patients regain muscle function and strength.

Treatments can include medication, exercise and physical therapy, heat therapy, orthotics, and rest.

It is one of three known inflammatory myopathies, a group of diseases that involve chronic muscle inflammation and weakness. Scientists believe they are autoimmune diseases, which means the body's defenses against invading organisms start attacking healthy tissue instead, producing swelling and weakness. 

Other names for this specific condition include:

  • ADM
  • childhood dermatomyositis
  • idiopathic inflammatory myopathy
  • IIM
  • Polymyositis

Various forms of the disease include:

  • adult dermatomyositis
  • dermatomyositis sine myositis
  • juvenile (childhood) dermatomyositis (JDMS)

A form of the disease that includes the rash but not muscle weakness is known as amyopathic dermatomyositis.

Signs and Symptoms of Dermatomyositis

Signs and symptoms vary widely from patient to patient. They can appear gradually over weeks and months (insidious) or flare up suddenly (acute). Sudden flareups are more common with the juvenile form of the disease.

A skin rash precedes muscle weakness and inflammation. The rash is patchy, with red or bluish-purple discolorations (heliotrope rash), and may produce skin ulcers.

It most commonly appears on eyelids and on muscles used to extend or straighten joints. Rashes are also common on the back, neck, face, cuticle areas, shoulders, and upper chest. The affected skin can also be characterized by increased pigmentation known as a Gottron sign. 

The rash can produce swelling when it strikes, and affected areas may become scaly over time. Eventually, scarring occurs, leading to a loss of color (depigmentation) of patches of skin (vitiligo).

Lesions sometimes develop on the scalp, producing scaling and itching that can produce significant hair loss.

Children who are affected by dermatomyositis can also develop calcium deposits. These hard bumps appear under the skin, and this condition is called calcinosis.

Although they can occur in adults, calcinosis most often appears in children one to three years after ADM first appears.

Some patients also accumulate plaque in their arteries (atherosclerosis), leading to potential cardiovascular issues. In rare cases, the heart can weaken (cardiomyopathy), or an irregular heartbeat (arrhythmias) can develop.

When chest muscles or the diaphragm are affected, dermatomyositis can also lead to breathing problems, including life-threatening complications if treatment is not initiated promptly.

Adults will often have a low-grade fever, lose weight, suffer from inflamed lungs, and will be light sensitive 2. Other symptoms can include problems swallowing (dysphagia) and fatigue.

In some cases, dermatomyositis is also associated with collagen-vascular or autoimmune diseases, such as lupus 3.

Some people also suffer from persistent blue coloring in their hands, feet, and face (acrocyanosis).

Muscles can be stiff and sore and will start to show signs of atrophy over time. This will create problems performing some motor skills, including raising arms, climbing stairs, or speech difficulties (dysphonia). Pain in multiple joints (polyarthralgia) also results due to muscle issues.

In more advanced and chronic forms of the disease, some joints become permanently bent in a flexed position, which can also lead to problems walking. 

Prevalence and Risk Factors of Dermatomyositis 

Dermatomyositis is not common. This rare disease affects less than 10 of every 1 million people in the United States 4.

The juvenile form of dermatomyositis affects about three of every 1 million children.

Dermatomyositis can develop in anyone at any time. But according to the Mayo Clinic, it is most common in children between 5 and 15, and adults between 40 and 60.

Also, females are stricken by it twice as often as males.

Causes of Dermatomyositis


The cause of dermatomyositis is not known. Some researchers theorize that it is triggered by an autoimmune reaction or a viral infection. Some researchers also think specific populations may have a genetic susceptibility to the disease.

Dermatomyositis has many of the same characteristics as an autoimmune disease. Autoimmune diseases occur when the cells in your body that fight disease (antibodies) attack healthy cells instead 5.

When your immune system is weakened, that makes it easier for a viral infection or other diseases such as cancer to also weakening your immune system. In turn, this can lead to dermatomyositis.

If you have dermatomyositis, your immune system attacks and obstructs the blood vessels inside your muscles and your skin’s connective tissues. This creates problems for the regeneration of muscles.

The genetic link is evidenced by the fact that with the condition, there is an increased frequency of “human leukocyte antigens” (HLAs).

These are proteins that are important to your body's immune system and have an influence on a person's likelihood of developing certain diseases. Research continues in this area, and the full implications of the genetic link are still not completely understood.

Some research indicates the infectious viral sources can trigger dermatomyositis. Some of these include:

  • coxsackie virus
  • parvovirus
  • echovirus
  • HIV
  • human T-cell lymphotrophic virus Type 1
  • Toxoplasma and Borrelia species

Researchers also theorize that, in some genetically predisposed people, foreign viral proteins called antigens that are similar to the body's proteins may trigger a response that causes the body to react against healthy cells.

In some cases, environmental factors can also trigger juvenile dermatomyositis, especially during April and May.

In a few cases, there have even been reports of dermatomyositis appearing after some vaccinations that use particular medications such as penicillamine, the statins, quinidine, and phenylbutazone). The hepatitis B vaccine also has been linked in a few cases.

Also, dermatomyositis may activate or grow worse after silicone breast implants or collagen injections.

Because it is so rare, more findings and case studies are needed to substantiate the link between these causes and the disease definitively.

Does Dermatomyositis Run in Families?
 

It’s possible that dermatomyositis can run in families. Some researchers believe that a mother’s blood cells can mix with a fetus during pregnancy that could later result in an autoimmune disease 6.

Potential Complications of Dermatomyositis 

Several possible complications can develop as a result of dermatomyositis. Some of them include:

  • Lung infections
  • Aspiration pneumonia
  • Fibrosis (scarred lung tissue)
  • Interstitial lung disease that can result in coughing and breathing difficulties
  • Connective tissue diseases such as rheumatoid arthritis, scleroderma, lupus, and Sjogren's syndrome
  • Gastric ulcers that can lead to vomiting of blood
  • Malnutrition and weight loss
  • Myocarditis
  • Pericarditis – swelling of the membrane around the heart
  • Pulmonary arterial hypertension
  • Congestive heart failure and arrhythmia
  • Increased risk of developing cancers, especially in people over age 40. Dermatomyositis can also develop after a diagnosis of cancer.
  • Raynaud’s phenomenon, a sudden contraction of blood vessels supplying the fingers and toes that interrupts blood flow and results in numbness, tingling, pain, and an abnormal discoloration of the digits. It is most commonly triggered by exposure to the cold.
  • Calcification of muscles and tissues (more common in juvenile dermatomyositis)
  • Abdominal pain and constipation
  • When ankles stiffen, it can produce a tiptoe gait in children
  • Bacterial skin infections
  • Gangrene - a less common but serious side effect as body tissue dies due to a lack of blood flow or infections.

Diagnosing Dermatomyositis 

The distinctive skin rash associated with dermatomyositis makes a preliminary diagnosis much easier than with other inflammatory muscle diseases.

But there are still many other tests you could undergo to confirm the diagnosis:

  • In addition to a physical exam and a medical history, your doctor may also order an MRI to look for abnormal muscles. Muscle and skin biopsy are also standard procedures. These help rule out other diseases. Elevated levels of enzymes, such as creatine kinase (CK), aspartate aminotransferase, lactic dehydrogenase, and aldolase, can indicate muscle damage.
  • An electromyography (EMG) will be taken to record electrical impulses that control your muscles. A thin needle with an electrical impulse is inserted into your muscle. Measurements are then recorded to see the amount of electric output there is when you tighten and relax.
  • Blood work will check your levels of muscle enzymes and autoantibodies (the antibodies that attack normal cells)
  • A chest X-ray to check for lung damage
  • An MRI to check cross-sectional images of your muscles
  • Computed tomography (CT) scanning
  • X-rays may be taken to reveal calcifications in soft tissues. 
  • Stool samples can be used to detect blood, which will indicate gastrointestinal issues.
  • Gynecologic exam and mammogram tests


Is There a Genetic Test for Dermatomyositis?

Researchers are still studying the link between genetics and dermatomyositis. It is not a genetic disorder, but there may be genetic factors that make it more likely that certain related conditions will develop.

You can learn more by accessing a scientific study, "Genome-wide Association Study of Dermatomyositis Reveals Genetic Overlap with other Autoimmune Disorders."

Treatment and Care Options for Dermatomyositis 

Although there is no cure, dermatomyositis symptoms can be treated. It is common for many types of specialists to provide coordinated treatment and care for patients.

Medications. These include corticosteroids such as prednisone, which is often a front-line defense. The downside is that prolonged use can have serious side effects (i.e., decreased bone density and brittle bones, swelling, weight gain, etc.).

Corticosteroid-sparing agents may be used in combination to lower the dose and side effects of a corticosteroid. Two commonly used medications for dermatomyositis are azathioprine (Azasan, Imuran) and methotrexate (Trexall). 

In some cases, especially children, symptoms may disappear entirely after corticosteroid treatment. Remission may be long-lasting, and sometimes even permanent.

Doctors may also prescribe Rituximab, which is more commonly used to treat rheumatoid arthritis or antimalarial medications to help control a persistent rash.

Immunosuppressive drugs that treat inflammation include cyclosporine A, cyclophosphamide, and tacrolimus.

Sunscreens are highly recommended to protect your skin from sun exposure. You will also be advised to wear protective clothing and hats as well to manage rash symptoms.

Physical therapy. It is often prescribed to prevent muscle atrophy and maintain a good quality of range of motion.

Speech therapy. Used when you have difficulties swallowing. In some cases, dietary changes may also be needed to create foods that are easy to eat 7.

Surgery. This may be an option to remove calcium deposits that cause nerve pain and infections.

Intravenous immunoglobulin. This purified blood product has healthy antibodies from thousands of blood donors that can block damaging antibodies in your system 8.

Orthotics. Also, devices that help you stand and move.

The Prognosis of Dermatomyositis 

The prognosis for those affected by dermatomyositis varies widely. In some cases, people recover, and symptoms disappear entirely, never to return.

Unfortunately, in others with severe cases, death can result from severe muscle weakness, malnutrition, heart and lung issues, and other complications 9.





What to do Next: Living with Dermatomyositis 

There are several resources you can access to learn more about how to manage dermatomyositis.

Cure JM Foundation
P.O. Box 45768
Baltimore, MD 21297
Telephone: (760) 487-1079
E-mail: [email protected]
Website: http://www.curejm.org/ 

Myositis Support and Understanding
9125 N. Old State Road
Lincoln, DE 19960
Toll-free: 1-888-MYO-RARE (696-7273)
Telephone: +1-302-339-3241
E-mail: [email protected]
Website: https://understandingmyositis.org/ 

Myositis UK
146 Newtown Road
Woolston
Southampton
SO19 9HR
United Kingdom
Telephone: 023 8044 9708
E-mail: [email protected]
Website: https://www.myositis.org.uk/ 

The Myositis Association (TMA)
1940 Duke Street
Suite 200
Alexandria, VA 22314
Toll-free: 1-800-821-7356
Telephone: +1-703-299-4850
Fax: +1-703-535-6752
E-mail: [email protected]
Website: https://www.myositis.org/ 

American Autoimmune & Related Diseases Association, Inc.

22100 Gratiot Ave.

Eastpointe, MI 48021

Phone: (586) 776-3900

Toll-free: (800) 598-4668

Email: [email protected]

Website: http://www.aarda.org/

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126

Gaithersburg, MD 20898-8126

Phone: (301) 251-4925

Toll-free: (888) 205-2311

Website: http://rarediseases.info.nih.gov/GARD/

Muscular Dystrophy Association

National Office 222 S. Riverside Plaza

Chicago, Illinois 60606

Suite 1500

Chicago, IL 60606 USA

Phone: (520) 529-2000

Toll-free: (800) 572-1717

Email: [email protected]

Website: http://www.mda.org/


You can also join the Autoimmune Registry to help support research for dermatomyositis. This will allow you to share information with researchers and get updates about participating in research studies.

Referenced Sources

  1. Dermatomyositis.
    Mayo Clinic. Aug 01, 2017.
  2. Dermatomyositis.
    Genetic and Rare Diseases Information Center (GARD). February 2020.
  3. Dermatomyositis.
    Genetic and Rare Diseases Information Center (GARD). February 2020.
  4. What Is Dermatomyositis?
    WebMD Medical Reference. Reviewed by Debra Jaliman, MD. March 14, 2019.
  5. Dermatomyositis: What Is It?
    Carmella Wint and Marijane Leonard. Reviewed by Brenda B. Spriggs, MD, MPH, FACP. July 26, 2017.
  6. Dermatomyositis.
    Muscular Dystrophy Association. Retrieved online, February 2020.
  7. Dermatomyositis.
    Mayo Clinic. Aug 01, 2017.
  8. Dermatomyositis: What Is It?
    Carmella Wint and Marijane Leonard. Reviewed by Brenda B. Spriggs, MD, MPH, FACP. July 26, 2017.
  9. Dermatomyositis.
    Genetic and Rare Diseases Information Center (GARD). February 2020.