MDA leads the search for treatments and therapies for dermatomyositis (DM). The Association also provides comprehensive supports and expert clinical care for those living with DM.
In this section, you’ll find up-to-date information about DM, as well as many helpful resources. This information has been compiled with input from researchers, physicians and people affected by the disease.
As you learn more about DM, always remember that you’re not alone. MDA is here for you and your family, standing ready to provide help and hope. There is a place for you in the MDA DM community.
MDA provides support by:
Once you sign up with your local MDA office , you’ll begin receiving MDA’s quarterly Quest  magazine, where you’ll find news about research and health care, helpful products and devices, social and family issues, and more.
In addition, MDA will keep you informed through e-alerts, educational publications and speakers, seminars, videos and newsletters.
Please know that there’s a role for you in the fight against dermatomyositis. The MDA community is strong and dedicated, with opportunities for involvement at all levels, such as:
Please know that there’s an important role for every member of the DM community. We urge you to contact your local MDA office  to learn more.
A DM diagnosis doesn’t mean an end to your hopes and dreams. Changes, challenges and adaptations lay ahead, but also opportunity, fulfillment, joy and hope for a future free of dermatomyositis.
Never forget that MDA is here to help.
|Dermatomyositis mostly affects the muscles of the hips and thighs, the upper arms, the top part of the back, the shoulder area and the neck.|
Dermatomyositis is one of the inflammatory myopathies, a group of muscle diseases that involves inflammation of the muscles or associated tissues, such as the blood vessels that supply the muscles. A myopathy is a muscle disease, and inflammation is response to cell damage.
Another word for inflammatory myopathy is myositis. The myo root means muscle, and the itis root means inflammation; so a myositis is an inflammatory muscle disease.
DM is distinct among the muscle diseases for its manifestation in the skin (“dermato”). A reddish or purplish rash, presumably due to inflammation of surface blood vessels, may occur over the face, neck and chest; on the shoulders and upper back, resembling a shawl; and/or on the elbows, knees and ankles. The skin may be scaly, dry and rough. Sometimes it looks like a sunburn.
Other symptoms of DM include a condition called calcinosis, in which calcium is deposited just under the skin in hard, painful nodules, and panniculitis, inflammation of the fat lying just under the skin.
Over time, the inflammatory process in DM leads to destruction of muscle tissue, and is accompanied by weakness and sometimes pain. There can be loss of muscle bulk (atrophy).
The muscles of the shoulders, upper arms, hips, thighs and neck display the most weakness in DM. There also can be joint pain, inflammation of the heart and lung muscle tissues, as well as inflammation of blood vessels to other organs. For more, see Signs and Symptoms .
In most cases, the cause of an inflammatory myopathy is unclear. For some reason, the body’s immune system turns against its own muscles and damages muscle tissue in an autoimmune process. In DM, these cells attack the small blood vessels that supply muscles and skin.
DM is not a genetic disorder, although there may be genetic factors that make it more or less likely that an inflammatory myopathy will develop. For more, see Causes/Inheritance .
DM's onset is in childhood or adulthood, and its progression is gradual. In children, onset is usually between the ages of 5 and 14, and girls are affected more often than boys. Although inflammatory myopathies like DM can lead to great discomfort for at least a period of time, effective treatments are available, and for the most part these conditions aren’t life-threatening. In fact, many people recover partially or completely from DM.
New research in DM  is rapidly leading to increased understanding of DM and to more successful treatments. Scientists are examining factors that may trigger DM such as viruses, certain drugs or vaccines. All these factors are being studied so inflammatory myopathies like DM can someday be better understood, treated or perhaps prevented entirely.
|A reddish or purplish rash and scaly, rough skin are typical in DM.|
For many decades, DM was considered “polymyositis  with a rash.” It’s now known that the two diseases have some fundamental differences, but for most doctors, it’s still the skin (“dermato”) manifestations of DM that make it a distinct disorder among the muscle diseases.
In DM, a distinctive reddish or purplish rash, presumably due to inflammation of surface blood vessels, may occur over the face, neck and chest; on the shoulders and upper back, resembling a shawl; and/or on the elbows, knees and ankles. The eyelids may appear as if eye shadow has been applied.
The skin may be scaly, dry and rough. Sometimes it looks like a sunburn.
Skin involvement in DM isn’t limited to rashes.
A condition called calcinosis, in which calcium is deposited just under the skin in hard, painful nodules, also can occur, and seems to be more common in children with DM.
Inflammation of the fat lying just under the skin, called panniculitis, also can occur, causing tenderness and feeling like little bumps.
The muscles of the shoulders, upper arms, hips, thighs and neck display the most weakness. The swallowing muscles can be involved, and a few people have difficulty chewing because of muscle weakness.
The weakness usually becomes noticeable over the course of several weeks, but it can move faster (days) or more slowly (months).
Joint pain with or without true arthritis (joint inflammation) can be part of DM.
Constriction of the blood vessels around the heart and inflammation of the heart muscle tissue can lead to cardiac complications.
Inflammation of the lung tissues also can occur.
Patients with DM can have some inflammation of the blood vessels of the intestinal tract, eyes and kidneys, and these organs can be damaged as a result.
As with other muscle diseases, a doctor diagnoses dermatomyositis (DM) by considering an individual’s history, family medical history and the results of a careful physical examination. This may be followed by some lab tests, perhaps of the electrical activity inside the muscles, and usually a muscle biopsy .
After a careful history and physical exam to document the pattern of weakness in the patient’s muscles, a doctor who suspects myositis likely will order a blood test to check the level of creatine kinase (CK) , an enzyme that leaks out of muscle fibers when the fibers are being damaged. In DM, the CK level is usually very high.
In some cases, the doctor may ask for a blood test for specific antibodies, proteins produced by the immune system in myositis and other autoimmune diseases. Some of these antibodies appear to be specific to autoimmune muscle disease.
The next step is sometimes an electromyogram , a test in which tiny needles are inserted into the muscles to test their electrical activity both at rest and when the person tries to contract the muscle.
Inflammatory myopathies show a distinctive pattern of electrical activity that can help differentiate them from other types of muscle disease.
A nerve conduction velocity test is sometimes performed. This test measures how fast a nerve impulse travels and how strong it is.
Sometimes these tests are used to rule out disorders that may mimic the symptoms of inflammatory myopathies.
A person with a suspected inflammatory myopathy is often asked to undergo a muscle biopsy, a procedure in which a small piece of muscle is removed for examination. This biopsy can enable the physician to pinpoint the diagnosis to a type of myositis.
In DM, the pattern of cellular invasion suggests that it’s the blood vessels in the muscles, and not the muscles themselves, that are the target of the attack. Muscle cells appear smaller than normal around the edges of bundles of muscle fibers, and capillaries are scarce in these regions.
|In DM, inflammatory cells are concentrated around blood vessels at the borders of the muscle fiber bundles (fascicles), and fibers in this region often shrink. Inflammatory cells can sometimes be seen forming a cuff around blood vessels.|
In the overwhelming majority of cases, there’s no clear cause for the development of myositis.
Viruses might be a trigger for autoimmune myositis. People with the HIV virus, which causes AIDS, can develop a myositis, as can people with a virus called HTLV-1. Some myositis cases have followed infection with the Coxsackie B virus.
There are reports of myositis following exposure to certain drugs. Among the drugs that have been suspected of contributing to myositis are carticaine (a local anesthetic), penicillamine (a drug used to lower copper levels in the body), interferon-alpha (mostly used to treat cancer and hepatitis), cimetidine (used to treat ulcers), carbimazole (to treat thyroid disease), phenytoin (used to treat seizures) and growth hormone. The vaccine for hepatitis B also has been implicated in some cases.
Recent research suggests that the mixing of blood cells of a mother and a fetus during pregnancy could lead to the later development of an autoimmune disease such as myositis in the mother or the child.
Dermatomysitis (DM) is a highly treatable disease. Some people, especially children, recover completely, while others experience greatly diminished symptoms for long periods of time. Several years of treatment to suppress the immune system may be necessary to achieve these results.
Those who don’t recover completely may need to continue on at least a low dose of medication to control the autoimmune attack of DM throughout their lives.
Drugs that suppress the immune system are the mainstay of therapy. The chart below describes the common treatments for DM and how they work. Treatment is similar to that for the muscle disease polymyositis (PM) .
Avoidance of sun exposure during peak hours and use of sunblock and protective clothing are recommended to avoid exacerbating the skin aspects of the disease.
Children with DM are treated with the same medications and therapies as adults. They may have to be kept out of physical education classes during periods of acute disease activity.
Myositis and You: A Guide to Juvenile Dermatomyositis for Patients, Families and Healthcare Providers, is a 480-page book written by experts in this disease and the grandmother of a child affected by it. Published in 2007, it’s available at bookstores and through the Internet.
Permanent loss of strength and muscle atrophy sometimes occurs in DM, but in other cases, full strength and muscle size are recovered.
|Medication or treatment||How it works||Comments|
corticosteroids prednisone tablets (Deltasone);
intravenous methylprednisolone sodium
|Dampens inflammation and immune response by interfering with processing of antigens and with early triggering of T cell and B cell production and later proliferation of B cells and T cells. These cells are produced by the immune system in autoimmune diseases such as PM and DM.||Can be taken orally as prednisone and related compounds; also available for intravenous use. Many side effects with long-term, high-dose therapy, such as weight gain and redistribution of fat to face, abdomen and upper back; thinning of skin; susceptibility to infection; bone loss; muscle damage; cataracts; elevated pressures in eyes (glaucoma); psychological disturbances; high blood pressure; high blood sugar; growth slowing in children.|
|Interferes with proliferation of B cells and T cells.||Can suppress production of several types of blood cells, so cell counts must be monitored; increases risk of cancer.|
|methotrexate (Rheumatrex, Folex, Mexate)||Interferes with proliferation of B cells and T cells.||Can cause liver damage; used in higher doses to treat cancer.|
|Keeps T cells from stimulating production of more T cells and B cells (“upstream” of azathioprine and methotrexate action).||Doesn’t affect production of cells other than T cells and B cells; can cause kidney damage, infection, high blood pressure, tremor and excessive hair growth.|
|Interferes with proliferation and activity of B cells and T cells||Also used in cancer; toxic to many kinds of cells, including those of the blood and bladder; can cause sterility in both sexes.|
|Interferes with proliferation of B cells and T cells.||Can cause diarrhea, vomiting, infection (particularly with cytomegalovirus); increases risk of cancer, especially lymphomas; causes depletion of certain blood cells.|
|tacrolimus (Prograf, old name FK506)||Keeps T cells from stimulating production of more T cells and B cells (“upstream” of azathioprine and methotrexate action).||Can damage kidneys; can cause headaches, tremors and sleep difficulties; diarrhea, nausea and vomiting; high blood pressure, high blood sugar and high blood levels of potassium; increases risk of infection and lymphomas. Drug breakdown interfered with by grapefruit juice; potential for kidney damage increased by some anti-inflammatory drugs.|
|Mechanism not understood; used in arthritis, lupus, malaria; can be used to reduce steroid dosage in myositis, particularly in children.||Can treat muscle symptoms and dermatomyositis rash. Can cause damage to eyes’ retinas or corneas; regular eye exams needed.|
infusion of mixed
(Gammar, Gammagard, Sandoglobulin,
|Has complex actions on immune system, such as providing antibodies against patient’s own antibodies; interfering with immune system reaction to antibody-marked cells; interfering with blood-transported chemicals released by immune system; interfering with activation and maturation of T cells and B cells.||Doesn’t affect production of cells other than T cells and B cells; can cause kidney damage, infection, high blood pressure, tremor and excessive hair growth.|
|plasmapheresis||Removes antibodies and proteins made by the immune system from the blood and returns “cleansed” blood to patient.||Very rarely used in myositis since 1992 study showed it was no more effective than placebo; some think it’s useful when combined with immunosuppressant drugs.|
Researchers supported by MDA are studying the underlying mechanisms that cause inflammatory myopathies, such as dermatomyositis (DM).
Several MDA projects are centered around understanding precisely what triggers the immune system to mistakenly attack muscle tissue, with the ultimate goal of stopping this type of attack.
Some MDA-funded researchers are developing cellular models of muscle injury in DM and are screening these models to learn the basic mechanisms by which muscle injury occurs in this disease.
They're paying particular attention to the role of interferons, proteins normally produced by immune system cells in response to a viral infection, in DM. There's evidence that type 1 interferons injure muscle in DM, and the researchers are seeking to identify compounds that prevent such injury.
Other investigators are studying inflammatory myopathies in dogs. They believe these animals may offer insight into the mechanisms by which autoimmunity develops in these diseases in humans.
At the same time, many clinical trials of medications  used to modify the immune system are under way in DM.
For more about research in and medical management of DM, see the following stories:
A clinical trial is a test in humans of an experimental medication or therapy. Clinical trials are experiments, not treatments, and participation requires careful consideration.
Although it's possible to benefit from participating in a clinical trial, it's also possible that no benefit — or even harm — may occur. Keep your MDA clinic  doctor informed about any clinical trial participation. (Note that MDA has no ability to influence who is chosen to participate in a clinical trial.)
For a more refined list of DM clinical trials, visit ClinicalTrials.gov , a registry of federally and privately supported clinical trials in the United States and around the world. Select "Search for Clinical Trials," and follow the instructions to narrow down your search results.
The first time I heard the word "dermatomyositis," I had to have it repeated and then spelled out for me.
|Photo of Robin Chavez by Christian Steiner|
I was scared and confused. I could barely comprehend what the doctor was saying to me. I was young, a newlywed, with a promising career as an opera singer, and had just been told I had a serious disease. I thought to myself, what is happening to me?
For months, I had experienced trouble walking, climbing stairs, even singing. Now I learned that I had a rare inflammatory muscle disease that affects fewer than 20,000 people in the United States.
Perhaps you’re reading this because you, or someone you love, also received a diagnosis of dermatomyositis (DM). As I did, you’re probably wondering what this will mean for your future, your family, your dreams. You may be feeling worried and confused — and even angry.
As you gain a clearer understanding of the causes, symptoms, complications and treatments for DM, you’ll learn that, although this inflammatory muscle disease can cause great distress initially, the symptoms can be alleviated with proper treatment. In fact, it’s possible to recover partially or completely from DM.
As soon as I received my diagnosis in 1996, I contacted the Muscular Dystrophy Association. My local MDA office  was very helpful, providing information, answering all my questions and helping me get established at the MDA clinic, where a course of treatment was started.
It wasn’t easy, but slowly things got better, and I felt my strength returning. At the beginning of my treatment, I couldn’t manage to climb even a couple of stairs. But a few years later, I walked up 120 steps to my hotel room when I sang in Rome. In 2000, I sang for a national audience on the MDA Telethon, and I continue to perform nationally and internationally.
I also continue to visit my MDA clinic, where my treatment is monitored and adjusted as needed. Local MDA staff also direct me to resources or simply let me know I’m not alone in coping with this disease.
It can be painful coming to terms with what life has handed you and making the necessary adaptations. I know it was for me. But like me, I hope you find that your myositis isn’t a dead end in your life’s journey.
I still face challenges due to DM, but I’ve learned these challenges can be successfully managed. As a single mother of three wonderful children, I know support is there for me from my family and friends, my medical team, and even from laws such as the Americans with Disabilities Act. And happily, my singing career continues to thrive.
When I first received my DM diagnosis, it was important to me that I continue to pursue my dreams. DM hasn’t stopped me but has motivated me to fight even harder to do what I love. I pray this also is true for you. And remember: As you face this challenge, you’re not alone in your fight!