Myositis refers to conditions causing muscle inflammation and damage. It usually results in weakness, fatigue, and challenges with activities.
What is myositis?
Myositis is a group of rare inflammatory diseases that cause muscle inflammation, resulting in muscle fatigue and weakness. The exact cause of myositis is unknown, but it is thought to be an autoimmune disease, meaning the body's immune system mistakenly attacks its own healthy tissues.
For many who’ve been diagnosed, myositis life expectancy has significantly improved with modern treatments. The best way to get a personalized understanding of prognosis is to discuss it directly with your AHN healthcare provider who is experienced in treating the different types of myositis and developing a care plan to fit your unique needs.
AHN Neuromuscular Division
Myositis treatment is managed within the AHN Neuromuscular Division, which allows our team to work in a multidisciplinary manner so you can experience a continuous care experience where the different specialties work together to deliver your care.
Our physicians and other specialized clinicians have decades’ worth of experience in serving patients with diseases of the peripheral nerves, neuromuscular junction, and muscle, including myositis. Several of our physicians are certified by both the American board of Clinical Neurophysiology and the American Association of Electrodiagnostic Medicine.
Why choose AHN for your myositis treatment
At AHN, the team is made up of highly trained physicians, specialists, and healthcare providers who are experienced in diagnosing and treating the many forms of myositis, including dermatomyositis and polymyositis. We offer a range of effective therapies, from medication to rehabilitative care, to relieve your symptoms and improve your quality of life.
Myositis symptoms and signs
Your myositis symptoms will depend on the type of myositis you have. All forms of the condition cause chronic muscle inflammation that can show up in different ways throughout your body. Common symptoms include:
- Difficulty getting up from a seated position.
- Problems climbing stairs.
- Discolored (red or purple) rash on the eyelids, elbows, knees, and knuckles.
- Feet and leg swelling.
- Muscle fatigue and weakness.
- Muscle and joint pain.
- Trouble lifting your arms.
Causes and risk factors
The exact cause of many types of myositis is largely unknown, though non-genetic cases are primarily classified as autoimmune. This means that the body's immune system, which is supposed to protect against foreign invaders like bacteria and viruses, mistakenly attacks its own healthy muscle tissues.
While the specific trigger for this autoimmune response is often unclear, it's believed to be a combination of genetic predisposition and environmental factors. The risk factors and causes for developing myositis often include:
- Infections: Viral or bacterial infections can trigger an immune response in genetically predisposed individuals. The immune system, while fighting off an infection, might mistakenly target muscle tissue.
- Specific medications: In some cases, exposure to certain drugs (e.g., statins, certain antibiotics, or immune checkpoint inhibitors used in cancer treatment) have been linked to drug-induced myositis, which usually resolves after stopping the medication.
- Toxins/chemicals: Exposure to certain environmental toxins or chemicals have been proved, though strong direct evidence can be lacking.
- UV exposure: For dermatomyositis, UV light exposure is a known trigger for skin symptoms and can precede disease onset.
- Other autoimmune diseases: Individuals who already have other autoimmune conditions (like lupus, rheumatoid arthritis, or Sjogrens disease) are at a higher risk of developing myositis.
- Cancer: The immune system may react to the cancer cells and mistakenly attack muscle tissue as well. The types of cancers most commonly associated include ovarian, lung, gastric, pancreatic, and colorectal cancers, as well as non-Hodgkin lymphoma.
- Age and sex: Myositis can affect people of all ages, including children (juvenile myositis), but it typically has two peak onset periods: childhood (5 – 15 years) and adulthood (40 – 60 years).
Myositis screening and diagnosis
To screen and diagnose for myositis, your AHN neuromuscular expert will talk through your symptoms, medical and family history, and how your life has been impacted by your myositis symptoms.
Once we have a full understanding of your symptoms, we will perform a thorough neurological examination and the necessary tests and imaging studies. These tests and imaging studies will help your care team to better understand the extent of your myositis.
Electromyogram (EMG)
An EMG can reveal abnormal electrical patterns, such as spontaneous activity when the muscle is at rest, which indicates muscle fiber irritation or damage that happens with myositis. It can also show abnormal muscle movement or damage to the muscle cells themselves. This helps pinpoint whether the problem is within the muscle itself.
Nerve conduction studies
A nerve conduction velocity test measures the nerves’ ability to send electrical signals. We always perform it along with an EMG to help determine whether symptoms are related to your nerves or muscles. While myositis is a muscle disease, nerve conduction studies are crucial because some nerve disorders can mimic myositis symptoms.
Magnetic resonance imaging (MRI)
For myositis, an MRI can be particularly useful in visualizing muscle inflammation and damage. It can show areas of muscle edema (swelling) and fatty infiltration (muscle replacement by fat due to chronic damage), and even identify areas of active inflammation that can be good targets for a muscle biopsy.
Blood tests
Several blood tests are vital in diagnosing and monitoring myositis. Key indicators often include elevated levels of muscle enzymes. Checking thyroid hormone levels and liver function is important to rule out other conditions that can cause similar symptoms (like thyroid disorders or liver disease causing muscle weakness).
Muscle biopsy
A muscle biopsy is often considered the gold standard for confirming a diagnosis of myositis. A small piece of muscle tissue (typically from a weakened but not completely atrophied muscle) is surgically removed and examined by a pathologist to look for inflammatory cells infiltrating the muscle fibers (lymphocytes, macrophages), muscle fiber necrosis (death), regeneration of muscle fibers, and atrophy. AHN muscle biopsies in Pittsburgh are interpreted by our pathology chairman who happens to be a specialty nerve and muscle pathologist – a distinct advantage in having your biopsy at AHN.
Lumbar puncture
While myositis is primarily a muscle disease, a lumbar puncture is generally not a routine test for diagnosing myositis itself. It is more commonly performed when there's a suspicion of central nervous system involvement or other neurological conditions that might present with similar symptoms.
Types and stages of myositis
There are several distinct types of myositis that can progress in various ways, but they aren’t staged in a way that is similar to other diseases. Myositis types include:
- Polymyositis: Primarily affecting the shoulders, hips, and neck and causing progressive weakness, polymyositis can cause muscle tenderness, severe fatigue, and difficulty swallowing.
- Dermatomyositis: Characterized by both muscle weakness and a distinctive skin rash. The rash can appear on the eyelids, knuckles, chest, back, and other areas. Dermatomyositis can eventually affect the internal organs.
- Sporadic inclusion body myositis: This is a degenerative (worsening over time) muscle disease that commonly affects those over the age of 50. It can cause you to have problems with pinching and grasping and can cause falls.
Myositis treatment
Our neuroscience specialists work with you to tailor treatment to your symptoms and situation. And, when necessary, they work alongside our expert rheumatologic partners. This collaborative approach provides you with a high level of personalized care.
At AHN, we use a range of medications and rehabilitative therapies.
Medication
Your physician will help determine which medications would most benefit you. Corticosteroids or other immunosuppressants work to reduce the body’s immune response, decreasing inflammation and improving certain symptoms. This helps improve muscle strength and reduce pain.
Physical therapy
Certain exercises or activities may strengthen muscles and help you complete daily activities more easily. Our knowledgeable, caring physical therapists customize a physical therapy plan for your needs. This might include gentle exercises designed to maintain and improve muscle strength without causing further damage. They can also help with flexibility and endurance, making everyday tasks like walking, lifting, or climbing stairs less challenging.
Occupational therapy
Our specially trained occupational therapists help you relearn how to complete daily activities that have become difficult, enhancing your independence at home or work. If your myositis symptoms make tasks like dressing, bathing, cooking, or writing difficult, occupational therapists can teach you new ways to perform them. They might also suggest special tools or modifications to your home or workplace to make things easier and help you stay independent.
Speech therapy
Dedicated speech therapists help you address symptoms that make it difficult to talk or swallow. Myositis can sometimes weaken the muscles involved in speaking and swallowing. Our speech therapists can provide exercises to strengthen these muscles, improve your voice, and help you swallow safely and comfortably, reducing the risk of choking.
Orthopedic devices
Depending on your myositis symptoms and which muscles are affected, devices like leg braces, shoe inserts, or even canes can provide stability, reduce strain on weakened muscles, and help you move more safely and confidently throughout your day.
Myositis FAQs
Your AHN care team is here to help answer your myositis questions, so you can feel more confident in your prognosis and treatment.
Is myositis fatal?
While myositis can be a serious condition, it's generally not directly fatal for most people. With proper care and advances in myositis treatment, myositis life expectancy is very good and has improved over the years.
For many individuals, particularly those with dermatomyositis or polymyositis, proactive and consistent treatment can lead to good control of the disease, allowing them to live full lives. The goal of myositis treatment is to reduce inflammation, improve muscle strength, and manage any associated symptoms or complications.
However, in some cases, myositis can lead to severe complications that, if untreated or poorly managed, can be life-threatening. These complications might include:
- Severe muscle weakness: This can affect muscles crucial for breathing and swallowing, leading to respiratory failure or aspiration pneumonia (inhaling food or liquids into the lungs).
- Heart involvement: Myositis can sometimes affect the heart muscle, leading to conditions like myocarditis or arrhythmias.
- Lung involvement: Interstitial lung disease, where the lung tissue becomes scarred, can occur and significantly impact breathing.
- Cancer: Dermatomyositis, especially in older adults, can be associated with an increased risk of certain cancers. Detecting and treating the underlying cancer is crucial.
So, while myositis itself may not be immediately fatal, the complications can be. This is why early diagnosis and consistent myositis treatment are so critical. Regular monitoring and aggressive management of these potential complications are key to improving outcomes.
Contact us
To schedule an appointment or learn more about AHN neuroscience services, call 412-359-8850.