What is dermatomyositis?
Dermatomyositis is a rare disease that causes muscle weakness and rashes on your skin. It’s a form of myopathy. It can also cause severe symptoms that affect your ability to breathe and swallow.
Dermatomyositis is a form of polymyositis that affects your skin in addition to your muscles.
See your provider right away if you experience any symptoms of dermatomyositis. Some cases take months to develop, but dermatomyositis can develop quickly. The sooner you begin treatment, the more likely it is you can avoid having severe complications.
In rare cases, dermatomyositis can be fatal, especially in the first year after symptoms start. It can also increase your risk of developing certain kinds of cancer.
Dermatomyositis vs lupus
Dermatomyositis is similar to lupus and other autoimmune diseases. However, experts aren’t sure what causes dermatomyositis, so it’s not classified as an autoimmune condition.
If you have lupus, you might experience joint pain, skin sensitivities and rashes, and issues with your internal organs (brain, lungs, kidneys and heart). Many of your symptoms might come and go in waves — often called flare-ups.
Dermatomyositis causes muscle weakness and degeneration (tissue death) and a rash on your skin. It’s diagnosed with blood tests, biopsies and imaging tests.
Both dermatomyositis and lupus need diagnosed and treated as soon as possible. Visit your provider right away if notice any new symptoms.
Who does dermatomyositis affect?
Anyone can be affected by dermatomyositis, but some groups of people are more likely to develop it, including:
- Kids 5 to 15 years old.
- Adults 40 to 60 years old.
- Women or people assigned female at birth.
How common is dermatomyositis?
Dermatomyositis is very rare. Around 1 in every 100,000 people develop it each year.
How does this condition affect my body?
Dermatomyositis could affect your body for the rest of your life.
If it damages your muscles badly enough you might lose the ability to move or use a part of your body the way you used to. This usually takes years to develop, but some people experience severe muscle weakness earlier than others.
Dermatomyositis has also been found to increase your risk of developing certain types of cancer.
Dermatomyositis and cancer
Around 15% of people with dermatomyositis develop cancer later in their life. Some of the most common cancers people with dermatomyositis develop include:
Talk to your healthcare provider about your cancer risk and any screenings you need.
Symptoms and Causes
What are the symptoms of dermatomyositis?
The most common symptoms of dermatomyositis are muscle weakness and a rash on your skin.
Some people notice muscle weakness and a rash around the same time. You might have one symptom for weeks, months or even years without the other.
Muscle weakness might make it hard for you to do common motions, including:
- Sitting upright.
- Getting up from a seated position (like standing up from a chair or couch).
- Climbing stairs.
- Getting up after lying down.
- Washing your hair.
Dermatomyositis may cause a rash on your skin (especially on parts of your body exposed to the sun). Areas with a rash will be discolored and might be swollen. The most common locations include:
- Eyelids and around your eyes.
- Chest and the front of your shoulders (sometimes referred to as a v-sign rash).
- Neck and the back of your shoulders (a shawl sign rash).
Other symptoms of dermatomyositis include:
- Discoloration and bumps (sometimes referred to as Gottron papules) on your hands, especially near your knuckles.
- Calcium deposits under your skin, in your muscles or in your connective tissue.
- Bumps on your knees or elbows.
- Ragged cuticles and prominent blood vessels on your fingernail folds.
- Joint pain.
Some people (especially kids) diagnosed with dermatomyositis grow out of it and never have symptoms again. However, 80% of cases are chronic (they come back over time) and cause lifelong symptoms.
What causes dermatomyositis?
Experts aren’t certain what causes dermatomyositis, but a few causes might include:
- Genetic factors: Some studies indicate dermatomyositis is a genetic disorder.
- Autoimmune issues: Dermatomyositis is similar to many autoimmune diseases that make your body's immune system attack healthy tissue.
- Viral infections: There’s some evidence that suggests a viral infection can trigger dermatomyositis in some people, even after the infection itself is cured.
- Environmental factors: Studies have found that living in areas with higher pollution or lower air quality might make you more likely to develop dermatomyositis.
Diagnosis and Tests
How is dermatomyositis diagnosed?
Dermatomyositis is usually diagnosed with blood tests and biopsies of your skin and muscles.
Your provider will test your blood for:
- Increased amounts of specific muscle enzymes that means something is damaging them.
- Autoantibodies (cells that show your immune system is reacting to something it detects as harmful).
You might need one of a few imaging tests. Your provider will use these to evaluate your muscles, nerves, lungs and other organs. These tests can help them determine if your symptoms are caused by dermatomyositis or another issue. The most common imaging tests used to diagnose dermatomyositis include:
In some cases, your provider may request an electromyography (EMG). This test measures electrical activity in response to muscle or nerve stimulation.
Management and Treatment
How is dermatomyositis treated?
Dermatomyositis treatments include:
- Corticosteroids: Corticosteroids will decrease the inflammation in your muscles.
- Physical therapy: Physical therapy (and exercise in general) can help rebuild damage in your muscles. The stronger your muscles are, the better equipped they are to handle any damage from dermatomyositis.
- Immunosuppressant medicines: Immunosuppressants stop your immune system from damaging healthy cells and tissues. They can slow down any damage your body’s defenses are causing in your muscles.
- Intravenous immunoglobulin (IVIg): IVIg is an infusion of extra immunoglobulin, a naturally occurring element of your blood’s plasma. IVIg treatments can work alongside immunosuppressants, or as an alternate treatment.
- Speech therapy: If you have muscle weakness in or around your throat, speech therapy can help you strengthen the muscles in your throat that help you swallow.
Which treatments you need depends on where you’re having symptoms, and how severe they are. Talk to your provider about what to expect and when you’ll need certain treatments.
How do I manage my dermatomyositis symptoms?
Managing your dermatomyositis symptoms will likely be a long-term process — possibly for the rest of your life.
- If your provider, physical therapist or speech therapist gives you exercises, do them as often as they suggest. This will help keep your muscles as strong as possible.
- Take any medications as often as you should for as long as your provider prescribes.
- Avoid UV exposure. Minimize your time in the sun, don’t use indoor tanning beds and take breaks indoors or under shade as often as possible while you’re outside.
- Use sunscreen whenever you know you’ll be outdoors. Make sure your sunscreen has an SPF rating of at least 50 and reapply it every two hours.
If you have dermatomyositis, it’s important to see your healthcare provider regularly. They’ll need to monitor your symptoms and make sure your condition isn’t spreading or getting more severe.
How soon after treatment will I feel better?
It might take a few months for your symptoms to improve after you start treatment. Most people living with dermatomyositis feel better as they regain their original levels of muscle strength after treatment.
How long it takes you to feel better depends on which treatments you need, which symptoms you’re experiencing and how severe they are.
Talk to your provider about what to expect and when you should notice your symptoms getting better.
How can I prevent dermatomyositis?
There’s no known way to prevent dermatomyositis. Because experts don’t know what causes it, there’s nothing you can do to prevent it.
Outlook / Prognosis
What can I expect if I have dermatomyositis?
There’s no cure for dermatomyositis. You should expect to manage your symptoms for the rest of your life.
Even with treatment, 80% of people have chronic dermatomyositis (sometimes referred to as polycyclic dermatomyositis). Your symptoms might come and go in waves throughout your life. Visit your provider right away as soon as you notice the signs of a symptom flare up.
Two-thirds of people living with dermatomyositis develop a physical disability because of the damage to their muscles.
What is the life expectancy of someone with dermatomyositis?
Dermatomyositis is fatal for approximately 5% of people diagnosed with it. This is especially true in the first year after being diagnosed. But, about 20% of people with dermatomyositis go into long-term remission.
Some symptoms and other factors can increase your risk of dying, including if you:
- Wait more than six months to start treatment.
- Are older than 60.
- Experience severe symptoms.
- Have symptoms in your throat, lungs or heart.
- Have or develop cancer.
When should I see my healthcare provider?
Visit your provider right away if you notice new weakness in your muscles, especially if you have a rash on your skin around the same time. The sooner dermatomyositis is diagnosed, the faster you can start treatment. This can decrease your chances of experiencing severe symptoms and other complications.
Ask your provider how often you should schedule follow-up visits so they can track your symptoms and any changes in your muscles or on your skin.
What questions should I ask my doctor?
- Do I have dermatomyositis or another condition?
- Which tests will I need?
- Which treatments will I need and how long will I need them?
- Will I need cancer screening?
A note from Cleveland Clinic
Being diagnosed with dermatomyositis can be extremely scary. Knowing you have a condition that will affect you for the rest of your life – especially one that can be fatal — is a huge shock. Take every day one step at a time. The sooner you’re diagnosed, the sooner you can begin treatment.
Talk to your provider about planning out your treatment and symptom management journey. They’ll help you understand what’s coming next and how to prepare for any changes you’ll need to make if the dermatomyositis causes more severe symptoms.
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