Dermatomyositis

Dermatomyositis is a rare disease that causes muscle weakness and rashes on your skin. It’s a type of myositis that affects your skin along with your muscles. It can also cause severe symptoms that affect your ability to breathe and swallow.

See a healthcare provider right away if you notice any signs of dermatomyositis. Most cases take months to develop. But dermatomyositis can sometimes develop quickly. Getting treatment as soon as possible is the best way to avoid having severe complications.

In rare cases, dermatomyositis can be fatal, especially in the first year after symptoms start. Some types can also increase your risk of developing cancer. But this is rare.

Dermatomyositis symptoms

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. But you may 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 without using your hands
• Climbing stairs
• Getting up after lying down
• Washing your hair

Dermatomyositis may cause a purplish red 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 your:

• 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, also called a shawl sign rash
• Scalp

You may have other symptoms, including:

• Discoloration and bumps (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 noticeable blood vessels on your fingernail folds
• Joint pain

Some people (especially kids) diagnosed with dermatomyositis grow out of it and never have symptoms again. But 8 in 10 cases are chronic. That means they come back over time and cause lifelong symptoms.

Dermatomyositis causes

Dermatomyositis is an autoimmune disease that makes your body’s defenses attack itself. Experts aren’t certain what causes this. Several factors may play a role, including:

• Environmental factors: Living in areas with compromised and/or low air quality might trigger dermatomyositis.
• Genetic factors: You may be genetically predisposed to develop this condition. Or your genetic makeup may make you more sensitive to environmental triggers.
• Viral infections: Experts think some viral infections can trigger dermatomyositis, even after the infection itself is cured.

It’s hard to pin down what causes dermatomyositis because it’s very rare. Once you have it, it’s usually more important to manage the symptoms and protect your body than to determine exactly why it happened.

Risk factors

Dermatomyositis more often affects females. Certain age ranges also have a higher risk, including:

• Kids 5 to 15 years old
• Adults 40 to 60 years old

Complications of this condition

Certain types of dermatomyositis can increase your cancer risk. Around 10 in every 100 people with it develop cancer at some point. Some common types include:

• Ovarian cancer
• Lung cancer
• Lymphoma
• Breast cancer
• Colon cancer

Talk to your healthcare provider about your cancer risk and any screenings you may need.

How doctors diagnose dermatomyositis

Dermatomyositis is diagnosed with blood tests, imaging, and biopsies of your skin and muscles.

A healthcare provider will test your blood for:

• Increased amounts of muscle enzymes, which means something is damaging your muscles
• Autoantibodies

You’ll also need a skin biopsy of any rashes. And your provider might biopsy your muscles to confirm inflammation inside them.

You might need some imaging tests, too. Your provider will use these to check the health of your muscles, nerves, lungs and other organs. These tests can help them determine whether the symptoms are from dermatomyositis or another issue. You may need:

• MRI
• Chest X-rays
• EMG

How is dermatomyositis treated?

Which treatments you’ll need depends on where you’re having symptoms and how severe they are. Talk to your healthcare provider about what to expect and when you’ll need certain treatments.

Dermatomyositis treatments can include:

• Corticosteroids: These medications decrease the inflammation in your muscles.
• Immunosuppressants: These 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.
• JAK inhibitors: Brepocitinib (Lisraya™) is a medication that blocks some enzymes involved in inflammation. It can help reduce symptoms like muscle weakness and skin rashes caused by dermatomyositis.
• Intravenous immunoglobulin (IVIG): IVIG is an infusion of extra, donated plasma. IVIG treatments can work alongside immunosuppressants or as an alternate option.
• Physical therapy: Physical therapy (and exercise in general) can help rebuild damage in your muscles. The stronger your muscles are, the better equipped they’ll be to handle any damage from dermatomyositis.
• Speech therapy: Speech therapy can help you strengthen the muscles in your throat that help you swallow. This is important if you have weakness in or around your throat.

When should I see my healthcare provider?

Visit a healthcare provider right away if you notice new muscle weakness, 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 can I expect if I have this condition?

It might take a few months for symptoms to improve after you start treatment. Most people living with dermatomyositis feel better as they regain their original levels of muscle strength.

How long it takes you to feel better depends on a few factors, including:

• The disease’s severity
• Which symptoms you have
• The treatments you need

There’s no cure for dermatomyositis. You should expect to manage it for the rest of your life. With treatment, you should be able to keep the disease stable. The symptoms might come and go in waves throughout your life. Visit your healthcare provider right away as soon as you notice signs of a flare-up.

You may develop a physical disability from the muscle damage. Dermatomyositis is fatal for approximately 5 in every 100 people with it. This is especially true in the first year after being diagnosed.

Some 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