Polymyositis - Causes, Risk Factors, Symptoms, and Treatment

What Is Polymyositis?

It is a type of muscle 'myopathy,' meaning the muscle fibers are incapable of functioning as required. Inflammatory myopathy is a type of muscle disease that causes inflammation in muscles and tissues. The most common symptom is muscle weakness and pain on both the right and left sides of the body. Mostly targets the muscle groups closest to the body's trunks, such as the hips, shoulders, thighs, upper arms, upper back, and neck. One can notice having trouble lifting arms overhead, rising from a chair, lifting or carrying things, and climbing stairs. It is most commonly seen among women and dark-skinned people. The disease can affect any age, mostly between the ages of 31 and 60. The disorder also involves inflammation of the skin, and it is referred to as dermatomyositis.

What Causes Polymyositis?

The exact cause of polymyositis is unknown. However, studies show it might be caused by autoimmune factors. This means the immune system attacks the body's own cells and tissues, causing inflammation and pain in the muscles and organs.

Is Polymyositis Hereditary?

The cause of this condition is not known. There are indications that heredity can cause the disease.

What Are the Risk Factors for Polymyositis?

The following diseases might increase the chances of getting polymyositis.

• Autoimmune disorders such as:

  • Rheumatoid Arthritis - Rheumatoid arthritis is a chronic inflammatory rheumatological disease that affects joints and muscles and causes pain, swelling, and inflammation in the joints and muscles.

  • Lupus Erythematosus - An inflammatory condition caused when the immune system attacks the body's healthy cells and tissues. Lupus can affect joints, lungs, kidneys, skin, blood vessels, and the brain.

  • Scleroderma - A rare chronic autoimmune disease that causes tightening and hardening of the skin and connective tissue.

  • Sjogren's Syndrome - A disorder of the immune system that causes dry eyes and dry skin.

• Respiratory infections.

• Viral infectious diseases such as HIV (human immunodeficiency syndrome) and AIDS (acquired immunodeficiency syndrome).

What Are the Signs and Symptoms of Polymyositis?

The following are the clinical features seen in polymyositis:

• Muscle weakness, pain, and stiffness.

• Swallowing difficulty.

• Irregular heart rhythms.

• Shortness of breath.

• Dry cough.

• Fever.

• Weight loss.

• Fatigue.

• Aspiration pneumonia.

• Consequences of severe and progressive muscle weakness.

• Rashes that appear violet or red may occur most commonly around the eyes.

• Arthritis.

• Speech difficulties.

What Is the Difference Between Polymyositis and Myositis?

Myositis is the inflammation caused in the muscle that is used in the movement. This condition can be caused by an autoimmune condition, infection, or injury. Polymyositis results in muscle weakness. This condition usually affects the muscles close to the body's trunk.

How Can Polymyositis Be Diagnosed?

Thorough clinical examination and detailed medical history are essential for proper diagnosis. In addition, the doctor recommends the following tests:

• Blood Tests - To rule out high levels of muscle enzymes, which can indicate muscle damage. This test also detects specific autoantibodies in the blood responsible for polymyositis.

• Antinuclear Antibodies Test (ANA) - This screening blood test is used to determine autoimmune disease.

• Erythrocyte Sedimentation Rate Test (ESR) - To measure the swelling and inflammation of the muscles.

• Muscle Biopsy - This is done to confirm the presence of muscle inflammation, typically only of polymyositis. It is a surgical procedure in which muscle tissue is extracted and examined.

• Electromyography (EMG) and Nerve Conduction Velocity Studies - These tests are electrical tests of muscle and nerves that can detect abnormal findings typical of polymyositis. Also, it can rule out other nerve-muscle disorders.

• Other Screening Tests - The doctor may order additional screening tests to diagnose other complications of polymyositis, such as a tumor and other disorders. It includes:

• Papanicolaou Test (Pap Smear): Cervical cancer or precancerous lesions in women are often diagnosed with the help of samples obtained from the cervix and are evaluated under a microscope.

• Chest X-ray: The more common complications involve breathing difficulties or even respiratory failure. Therefore, a chest X-ray might help diagnose any signs of lung complications.

• Mammograms: The signs of breast cancer can be detected with a specialized X-ray technique called mammograms.

Is Polymyositis Dangerous?

Untreated polymyositis may lead to the following serious conditions:

• Pulmonary disorders.

• Dysphagia (difficulty or discomfort in swallowing).

• Weight loss and malnutrition.

• Pneumonia aspiration occurs as a result of food or other substances entering the airways rather than going through the food pipe. It causes coughing, excessive sweating, chest pain, wheezing, and other breathing problems.

• Hypoventilation refers to inadequate ventilation that increases the blood's carbon dioxide levels.

• Interstitial lung diseases result in severe fatigue, weight loss, shortness of breath, and cough.

• Breathing difficulty.

Can Polymyositis Be Fatal?

Most people affected by polymyositis respond well to the treatment and regain muscle strength; however, some muscle weakness still persists. In many cases, polymyositis is not life-threatening. With proper treatment and initial diagnosis, symptoms can be limited.

What Are the Treatments Done in Polymyositis?

There is no such cure for polymyositis, so symptoms and pain can be managed. Treatment planning depends on age, medical history, symptoms, and general health.

Medications:

• Corticosteroids - Prednisone can be used to limit polymyositis symptoms and decrease inflammation in the muscles.

• Corticosteroids Sparing Agents - The most common drugs used are Azathioprine and Methotrexate. These drugs are used in combination with corticosteroids to decrease the side effects of corticosteroids.

• Rituximab - An option if initial therapies do not adequately control polymyositis symptoms.

• Drugs Suppressing the Immune System - Drugs like Azathioprine and Methotrexate are initially started.

Other Procedures:

Infusion of intravenous immunoglobulins has shown improved results in patients with polymyositis. For this procedure, blood from healthy donors is segregated by apheresis to collect the healthy immunoglobulins (Ig). Thus, the collected Ig is intravenously infused into the patients to prevent the muscles from damaging antibodies.

Therapies:

• Physical Therapy - It reduces inflammation, reduces fatigue, increases stamina, and builds muscles.

• Speech Therapy - If swallowing muscles are weakened, speech therapy may be beneficial.

• Heat Therapy and Rest - Reduces muscle symptoms.

Conclusion:

Polymyositis can be present with other illnesses. However, studies reveal that the condition may be due to the immune system malfunctioning. As a result, it may lead to various severe complications. Therefore, it is crucial to have a doctor's consultation as early as possible to manage the disease and for quick remission.