Dermatomyositis is rare, but it’s also not usually fatal if doctors diagnose and treat it early.

Dermatomyositis (DM) is a rare type of muscle disease that falls under an umbrella of conditions called idiopathic inflammatory myopathies.

The underlying inflammation associated with DM first begins in skin tissues before spreading to your muscles. It’s common to experience symptoms like muscle pain and weakness, as well as a loss of muscle tissue altogether.

In some cases, DM can cause further complications if the inflammation spreads to other parts of your body, such as your internal organs. However, DM itself isn’t necessarily fatal, especially if you’re receiving treatment for the condition.

Learn more about the factors that can affect your life expectancy with DM and when you should discuss these further with a medical professional.

DM is known for affecting muscles, particularly those located in your:

  • upper arms
  • trunk
  • hips
  • thighs

When the disease progresses, you may also experience symptoms and complications affecting areas outside of your skin and muscle tissues. These include your blood vessels, joints, and internal organs. You may even have difficulty with speaking and swallowing food.

DM can be fatal. However, deaths from these types of inflammatory conditions are considered rare. This is thanks to early treatments that can help stop the progression of DM.

On the other hand, people who do not seek treatment for DM may be at a higher risk of associated fatalities.

Some people with DM may experience significant muscle loss and weakness that can affect the chest and diaphragm. This can lead to breathing difficulties, which can be life threatening.

Cancer and ischemic heart disease are other possible fatal complications that can occur due to DM.

The overall life expectancy for people with DM depends on whether it’s treated or untreated. Most deaths from DM occur early after diagnosis.

According to one 2018 cohort study of 716 people, researchers found that 9% died from idiopathic inflammatory myopathy within a year of diagnosis.

Additionally, people with DM who don’t seek treatment within the first 6 months of experiencing symptoms may have a lower life expectancy.

Having DM doesn’t necessarily mean your condition is fatal, but certain risk factors can affect your overall life expectancy. These may include:

  • lung involvement
  • heart involvement
  • cancer
  • swallowing difficulties
  • significant muscle weakness

Older age is considered another factor that can affect life expectancy in DM more generally. However, research has also reported DM-related deaths occurring in younger adults with sudden onset of the condition.

Treatment for DM may help prevent related complications, such as life threatening respiratory failure.

Not all DM complications are life threatening, but some may decrease overall quality of life, which underscores the importance of prompt treatment in the early stages of this condition.

Common medications for this condition include glucocorticoids and immunosuppressants. Additionally, a doctor may refer you to a physical therapist who can help you build muscle strength and prevent related complications.

In the later stages of DM, it’s possible to experience the following symptoms:

  • dysphagia (swallowing difficulties)
  • chronic coughing
  • arrhythmia (irregular heartbeat)
  • atherosclerosis (plaque buildup in your arteries)
  • difficulty speaking
  • permanent joint changes
  • walking difficulties
  • inability to complete everyday tasks, such as getting dressed
  • gastrointestinal (GI) issues, such as abdominal pain and constipation

The onset of DM can be sudden or gradual. In either case, once you have DM, you may experience periods of flare-ups throughout your life. During these flare-ups, worsening skin rashes and muscle weakness can occur without any obvious cause.

It’s important to speak with a doctor for regular visits so they can help monitor the progression of DM and modify your treatment plan when needed. Follow their instructions for future physical exams as well as medications.

Furthermore, it’s worth noting that most people who undergo treatment for DM may achieve remission.

In between exams, it’s important to get medical help if you notice any signs that DM may be worsening. These include worsening symptoms that may affect your ability to:

  • walk
  • speak
  • breathe
  • cook or clean
  • get dressed

You should also consider contacting a doctor if you experience unintentional weight loss, low grade fever, and other unexplained symptoms.

DM is a rare type of muscle inflammation that can progress when left untreated. While it’s not usually fatal with treatment, DM life expectancy can depend on other factors, such as its effects on internal organs.

If you or a loved one has DM, it’s important to follow a doctor’s treatment plan and contact them right away if you’re experiencing new or worsening symptoms.

As with other inflammatory diseases, the outlook for those with DM is positive when treatment begins as soon as possible. Beyond life expectancy, DM treatment can also help preserve your quality of life.