Myositis
Myositis is a rare disease that makes your immune system attack your own muscles, causing chronic inflammation that leads to muscle weakness and fatigue. While there is no cure, treatment can help manage symptoms and improve quality of life.
Table of contents
- What is myositis?
- Types of myositis
- What causes myositis?
- Who gets myositis?
- Symptoms of myositis
- How is myositis diagnosed?
- Treatment and management
- Outlook and prognosis
- Living with myositis
What is myositis?
Myositis is a disease that makes your immune system attack your muscles. It causes chronic inflammation — swelling that comes and goes over a long time. Eventually, this inflammation makes your muscles feel increasingly weak and can also cause muscle pain.[1]
Myositis is a type of myopathy, a general term that refers to diseases that affect the muscles that connect to your bones (skeletal muscles). The term “myositis” refers to a set of autoimmune diseases involving chronic inflammation of the muscles. In autoimmune conditions, the body’s immune system, which normally fights infections and viruses, mistakenly attacks the body’s own normal, healthy tissue.[2]
Myositis is a rare disease. All forms combined affect an estimated 50,000 to 75,000 people in the United States.[2][6] Different forms of myositis affect different groups of muscles throughout your body. Myositis usually affects the muscles you use to move, including muscles in your arms and shoulders, legs and hips, abdomen and spine. Other people with myositis experience muscle weakness on or near their eyes, esophagus, or diaphragm.[1]
Types of myositis
A healthcare provider will diagnose a type of myositis based on your symptoms and the location of your affected muscles. There are several different forms of myositis, including polymyositis, dermatomyositis, inclusion body myositis, necrotizing myopathy, antisynthetase syndrome, and juvenile myositis.[2]
Polymyositis
Polymyositis affects multiple muscles at the same time. It usually causes symptoms in muscles on or near the center of your body. Polymyositis develops gradually over time and typically affects adults. Females are twice as likely to develop polymyositis than males.[1]
If you have polymyositis, you might have trouble performing movements you usually can, including standing up after sitting, climbing stairs, lifting objects, or reaching over your head.[1]
Dermatomyositis
Dermatomyositis is a form of myositis that affects your skin in addition to your muscles. 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.[1]
Dermatomyositis causes muscle weakness similar to polymyositis, but it also presents with skin rashes and other skin-related symptoms. The rashes tend to be purple-red in color and often appear on the eyelids, face, chest, neck, back, and joints. They are often sensitive to sunlight, bright light, and UV radiation.[6]
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. Anyone can experience dermatomyositis. If it affects children, it’s known as juvenile dermatomyositis.[1]
Inclusion body myositis
Inclusion body myositis is a degenerative muscle disease. It usually affects people older than 50 and is more common in men than women.[1][7]
Inclusion body myositis causes muscle weakness in your extremities — your hands and your legs below your knees. It can also affect the muscles in your throat that help you swallow. Around 30% of people with inclusion body myositis develop dysphagia (difficulty swallowing).[1]
If you have inclusion body myositis, it might be hard to use your hands and fingers to do precise tasks like buttoning a shirt, grip something small, walk or stand, or swallow.[1]
Other forms of myositis
Additional types include necrotizing autoimmune myopathy (also called immune-mediated necrotizing myopathy), which is characterized by less muscle inflammation and signs of muscle damage, and antisynthetase syndrome.[6][9]
What causes myositis?
Experts aren’t certain what causes myositis. Most types of myositis are autoimmune conditions, where the body’s immune system attacks itself, causing swelling of the muscles and joints.[4]
The muscle inflammation in myositis is caused by white blood cells of the immune system, which are normally supposed to protect the body from infections. In people with myositis, however, these cells mistakenly attack a person’s own healthy muscle fibers and can injure or destroy muscle fibers. This affects muscle function and can lead to fatigue and weakness.[6]
While it is still unclear what causes myositis, some scientists believe certain individuals have a genetic predisposition to develop an autoimmune disease, which is triggered by an environmental exposure to some trigger, such as infection, virus, toxin, or sunlight.[2] Myositis may be passed on from your parents in your genes.[4]
Myositis can also arise from other causes including injury, certain medications, and infections. In some instances, the origins of myositis remain idiopathic, without a discernible cause.[5]
Who gets myositis?
Although anyone can get myositis, there are numerous risk factors by age, sex, and ethnicity. People in their middle age, women, and those with Sub-Saharan African descent are at higher risk.[6]
A peak incidence of myositis takes place in people between the ages of 45 and 64, with about 8 to 10 new cases per 100,000 people per year. People in younger (25 to 44) or older (65+) age groups get myositis less often, with about 3 to 5 new cases per 100,000 people per year.[6]
Polymyositis and dermatomyositis affect women two to three times more than men, while inclusion body myositis affects men about one-and-a-half to two times more than women. People of predominantly Sub-Saharan African descent are three times more likely to get myositis than people with little or no such ancestry.[6]
Dermatomyositis has an average age of diagnosis that is bimodal, with juvenile dermatomyositis most commonly diagnosed between 4 and 14 years of age and adult dermatomyositis diagnosed between 40 and 60 years of age.[9]
Symptoms of myositis
The main symptom of myositis is muscle weakness. Myositis symptoms include muscle weakness, joint or muscle pain, fatigue, swelling, and trouble breathing or swallowing. If the myositis affects your heart, you might experience arrhythmia (irregular heartbeat).[1]
The muscle weakness often develops slowly and can be subtle at first. You might have trouble performing movements you usually can. During an episode of symptoms, you might have trouble moving or doing certain activities you usually can. You might get tired faster, or feel like you can’t control your arms, hands or legs.[1]
Common difficulties with muscle weakness
The most common symptom of myositis is muscle weakness. The weakness often develops slowly and can be subtle at first, influencing patients’ ability to do certain activities. They can have trouble doing tasks that require having their arms held above their head — things like washing, brushing, or blow drying their hair, reaching items on high shelves, or hanging up an overcoat can be hard. Additionally, they can have trouble getting up from low chairs, getting out of a car, or climbing steps. Patients can trip and be unable to catch themselves or be unable to get up from the floor after falling.[6]
You may also find it difficult to get up from a chair, climb stairs, lift objects such as a cup of tea, or comb your hair.[4]
Other symptoms
Depending on the type, other symptoms can include painful or aching muscles, feeling very tired, weight loss, night sweats, and a patchy, red rash (usually on the eyelids, face, neck and the backs of the hands in dermatomyositis — this can look different on brown or black skin).[4]
Sometimes, in the most severe cases, the muscles of the throat or diaphragm can weaken, leading to trouble swallowing or shortness of breath.[6] There may be times when your symptoms are better than at other times.[4]
Effects on other organs
Myositis can affect the whole body, not only the muscle. Some patients can have other symptoms such as arthritis in the hands that resembles those in rheumatoid arthritis, lung inflammation that causes coughing or shortness of breath, and skin inflammation or rashes. Each patient’s disease experience and mix of symptoms is unique. Some cases are very mild, while others are severe.[6]
How is myositis diagnosed?
Myositis is often difficult to diagnose, because many physicians are unfamiliar with the disease and its symptoms. If a GP thinks you have myositis, they will do a blood test and refer you to a specialist.[4]
A typical diagnosis process for myositis patients begins with a medical history and physical examination. The doctor assesses for muscle weakness or rashes. It may also include blood tests, muscle and skin biopsies, and a variety of other diagnostic tests.[2][5]
Diagnostic tests
The specialist may do more tests, including:[4]
- Blood tests to look for an elevation of creatine kinase in the blood, which is indicative of muscle inflammation
- An MRI scan
- An electromyography (EMG) scan to look at the electrical activity in your muscles. This test involves the insertion of small needles into the patient’s muscles, allowing a physician to look at the muscles’ responses to various electrical nerve stimuli and evaluate which muscles potentially have myositis.
- A biopsy to take samples of your muscle. Muscle biopsies are the most reliable tests for diagnosing myositis.
Magnetic resonance imaging can be useful in diagnosis, allowing painless, non-invasive visualisation of any muscle wastage.[5]
Treatment and management
There is no cure for myositis. However, management of the disease is critical to reduce inflammation caused by myositis and to prevent muscle weakness from progressing. Your healthcare provider will treat the symptoms you’re experiencing. There are two approaches to treatment for myositis: medical treatment and lifestyle management changes.[11]
Medical treatment
It’s not possible to cure myositis, but treatment can help control the symptoms. Treatment usually includes medicines, such as steroids, to reduce swelling and stop your immune system attacking your body.[4]
Your doctor will probably recommend a course of medical therapy using corticosteroids (such as prednisone) and other drugs that suppress the immune system (immunosuppressants). These may slow down the attack on healthy tissue and improve skin rash. Polymyositis and dermatomyositis are first treated with high doses of a corticosteroid.[3][11]
There is a general recommendation to combine corticosteroids with another immunosuppressive agent in the early phase of disease to better control disease activity and possibly to reduce the risk for corticosteroid-related side effects.[12]
If your myositis is severe or gets worse, you may be offered other treatments to stop your immune system’s response. These can include medicines (including some usually used to treat rheumatoid arthritis) and immunoglobulin therapy, which uses antibodies (part of the immune system) taken from blood donations.[4] There is some evidence for the effect of rituximab in patients with certain myositis-specific autoantibodies, whereas other biologic agents are currently being tested in clinical trials.[12]
You may also want to use nonsteroidal anti-inflammatory drugs (NSAIDS) such as aspirin or ibuprofen for pain relief.[11] Your doctor will probably repeat blood tests throughout your treatment for myositis to monitor improvement.[11]
Exercise and physical therapy
Combining pharmacological treatment with individualized and supervised exercise can be recommended based on evidence.[12] After drug treatment takes effect, a program of regular stretching exercises prescribed by your doctor can help maintain range of motion in weakened arms and legs. Physical therapy may also help prevent permanent muscle shortening. You may also want to add whirlpool baths, heat and gentle massage.[11]
Exercise is an important component of managing myositis. Physiotherapy can help you stay active and improve your muscle strength.[4] Exercise is medicine for myositis. Start slowly and increase as tolerated. Ask for physical therapy and/or occupational therapy if you need help with moving and managing at home.[23]
Other therapies
You may also be offered speech and language therapy if you have difficulties swallowing or communicating.[4]
Lifestyle management changes
Getting enough rest is an important component of managing myositis. Take frequent breaks during the day and limit your activity. Eat a well balanced diet. If there are concerns, a referral to a nutritionist for assistance may be helpful.[11]
It is imperative that myositis patients find outlets for the daily stress that most of us have in our lives. To that end, your doctor may suggest exercise as a form of relaxation, like yoga, or biofeedback exercises.[11]
Outlook and prognosis
Experts aren’t certain what causes myositis, and there’s no cure for it. In most cases, treatment can put it into remission.[1] With inadequate or no treatment, myositis can cause significant disability and even death.[2]
Myositis is a serious illness that, in most cases, needs to be treated aggressively. Nevertheless, myositis is a serious illness that, in most cases, needs to be treated aggressively. There is a lot of confusion among the medical community over how to effectively manage patients with myositis.[2]
Regrettably, for some forms of myositis, particularly inclusion body myositis, there are no treatments available yet.[15]
Living with myositis
Being diagnosed with a chronic, rare disease can be very disorienting for both patients and those who care for them. Suddenly life looks very different, and adjustments must be made to accommodate new limitations. Coming to terms with this new landscape can take some time, but there are things you can do to facilitate your adjustment.[18]
Be patient with yourself
Life after diagnosis will likely be very different than what you’re used to. The first year is the hardest; don’t give up.[23] Having a positive attitude when dealing with myositis is essential. During those dark moments when life seems to be falling apart, it is important to remember that you control your own emotions.[26]
Learn about myositis
Arm yourself with information. This is one of the very best ways to start your journey with myositis. Learn as much as you can from reliable sources, not from general internet searches. The search engine is nearly 20 years behind and sounds scarier than it often is.[18][23]
Seek support
Research has shown that people who receive support from a social network cope better, feel more in control, and have better outcomes than those who are isolated. Seek out others with myositis. Spending time with others with myositis helps them to know that they are not alone.[18][27]
Stay organized
Create a medical binder where you collect all the information about your condition, including visit summaries, test results, and questions you have for your next visit. This information is also essential for family and doctors if you are unable to speak at some point. Keep printed records of abnormal tests. Keep a list of all your medications, including those prescribed by non-myositis providers, over-the-counter drugs, and supplements. Also include drugs you did not tolerate and why, so providers do not try to prescribe them again.[23]
Manage your energy
Conserve your energy by cutting corners where you can, at home and at work. Ask for help. Consider tools to get others to do laundry, run out to the store, or bring your favorite food. Carpooling and other appointment help can be scheduled too.[23]
Keep moving
Keep moving as much as you can. Exercise is medicine for myositis. Start slowly and increase as tolerated.[23]
Accept and adapt
In order to cope with a loss of control, acceptance is important. Accepting your new lifestyle includes planning ahead and adapting to a new way of making decisions. The future plans you’ve made previously may no longer be possible, but you can still have future plans. They just may need some adjusting.[24]
A different life is not the same as one without fulfilment. Many people with myositis live exciting and gratifying lives. It might not always be easy and it is a continuous journey – but you can find ways to live with myositis.[19]