Polymyositis

Overview

Polymyositis is an uncommon inflammatory disease that causes muscle weakness affecting both sides of your body. The muscle weakness typically affects muscles closest to the trunk, such as those in your hips, thighs, shoulders, upper arms, and neck. The condition most commonly affects adults in their 30s, 40s, or 50s, with women being affected more often than men. Polymyositis does not have a known cure, but treatment options such as medications and physical therapy can help improve muscle strength and function. The disease is associated with other conditions like interstitial lung disease, cancer, Raynaud's phenomenon, and other connective tissue diseases. If you experience unexplained muscle weakness, it is important to seek medical attention.

Understanding the disease

Symptoms

The symptoms of polymyositis include muscle weakness affecting both sides of the body, particularly in the muscles closest to the trunk such as those in the hips, thighs, shoulders, upper arms, and neck. The weakness tends to develop gradually over weeks or months. Other associated conditions include Raynaud's phenomenon, other connective tissue diseases, cardiovascular disease, and lung disease. It is important to seek medical attention if you experience unexplained muscle weakness.

Risk Factors

The risk factors for developing polymyositis include having other connective tissue diseases such as lupus, rheumatoid arthritis, scleroderma, or Sjogren's syndrome.

Development

Polymyositis is an inflammatory disease that causes muscle weakness affecting both sides of the body. The exact cause of polymyositis is unknown, but it is believed to be an autoimmune disorder, in which the immune system mistakenly attacks the body's own tissues. Risk factors for developing polymyositis include having other connective tissue diseases such as lupus, rheumatoid arthritis, scleroderma, or Sjogren's syndrome. While there is no cure for polymyositis, treatment can improve muscle strength and function. Complications of the disease may include difficulty swallowing, aspiration pneumonia, breathing problems, lung disease, and an increased risk of cancer.

Assessment and Diagnosis

Triage

You should see a doctor if you develop unexplained muscle weakness, as this could be a symptom of polymyositis. Early diagnosis is important for effective treatment and management of the condition.

Diagnosis

To diagnose polymyositis, your doctor may suggest some of the following tests:

1. Blood tests: A blood test can help determine if you have elevated levels of muscle enzymes, which indicate muscle damage. Blood tests can also detect specific autoantibodies associated with different symptoms of polymyositis, which can help in determining the best medication and treatment.
2. Electromyography: This test involves inserting a thin needle electrode through the skin into the muscle. Electrical activity is measured as you relax or tighten the muscle, and changes in the pattern of electrical activity can confirm a muscle disease. The doctor can determine the distribution of the disease by testing different muscles.
3. Magnetic resonance imaging (MRI): A scanner creates cross-sectional images of your muscles from data generated by a powerful magnetic field and radio waves. Unlike a muscle biopsy, an MRI can assess inflammation over a large area of muscle.
4. Muscle biopsy: During this test, a small piece of muscle tissue is surgically removed for laboratory analysis. Analysis may reveal abnormalities, such as inflammation, damage, certain proteins, or enzyme deficiencies. It is important to note that the diagnosis of polymyositis is based on a combination of clinical presentation, laboratory tests, and imaging results. Your doctor will tailor your diagnostic approach based on your specific symptoms and medical history.

Management and Treatment

Complications

Potential complications of polymyositis include difficulty swallowing (dysphagia), aspiration pneumonia, and breathing problems. If the muscles in your esophagus are affected, you may have trouble swallowing, leading to weight loss and malnutrition. Difficulty swallowing may also cause you to breathe food or liquids into your lungs, potentially causing pneumonia. Polymyositis may also affect chest muscles, causing breathing problems like shortness of breath or, in severe cases, respiratory failure.

Treatment

The most commonly used medications to treat polymyositis include corticosteroids, corticosteroid-sparing agents, rituximab, and medications like azathioprine, methotrexate, mycophenolate mofetil, cyclosporine, and tacrolimus. Treatment aims to improve muscle strength and function, and doctors may tailor the treatment strategy based on the individual's symptoms and response to therapy. Additionally, physical therapy, speech therapy, and dietetic assessment might be recommended.

Preparing for medical consultation

To prepare for an appointment for polymyositis, you should:

1. Gather information about your family's medical history, particularly if your parents or siblings have any related medical conditions.
2. List all the medications and dietary supplements you are currently taking.
3. Prepare a list of questions ahead of time to ask your doctor, including:
   • What is likely causing my symptoms?
   • Are there other possible causes for my symptoms?
   • Are my symptoms likely to change over time?
   • What kind of tests might I need? Are any special preparations required?
   • Are treatments available for my condition? What treatments do you recommend?
   • How can I best manage other medical conditions I may have alongside polymyositis?
   • Do you have any brochures or printed materials I can take with me? What websites do you recommend?
4. Be aware of any pre-appointment restrictions, such as medication or dietary adjustments.
5. Write down your symptoms, including when they started and any changes over time.
6. Take a list of all your medicines, vitamins, or supplements.
7. Make a list of your key medical information, including other diagnosed conditions.
8. Write down key personal information, including any recent changes or stressors in your life and a detailed description of your typical daily diet.
9. Don't forget to ask questions during your appointment if you think of something new or need clarification. Remember to be honest and open with your doctor about your symptoms and medical history, as this will help them provide the best possible care and advice.