Polymyositis

It is a rare autoimmune rheumatic disease that causes widespread inflammation, weakness, and eventual wasting in the muscles, resulting from the body's defense mechanism (immune system) becoming confused and attacking its own voluntary muscle cells (striated muscles) as if they were viruses.

Dermatomyositis is a disease that affects both the muscles and the skin (with rashes/redness). In polymyositis, there is NO skin rash; the disease exclusively and entirely damages the muscle tissue (especially muscles proximal to the trunk).

The disease predominantly affects the muscles close to the center of the body—namely the shoulders, upper arms, hips, thigh muscles, and neck—in a symmetrical (equal on both sides) manner. The patient experiences extreme difficulty rising from a chair without support, climbing stairs, lifting their arms to comb their hair, and lifting their head off a pillow.

As the disease progresses, it can involve the muscles of the throat and esophagus, causing difficulty swallowing (dysphagia), and can weaken respiratory muscles, leading to shortness of breath. These situations require emergency intervention.

It is suspected when very high levels of Creatine Kinase (CK) and Aldolase enzymes, which are released when muscle is destroyed, are found in the blood. Inflammatory electrical activity in the muscles is recorded via EMG (Electromyography). A definitive diagnosis is established by observing lymphocytes (immune cells) invading the muscle fibers in a Muscle Biopsy taken from the leg or arm.

There is no completely eradicating cure for polymyositis, but muscle breakdown can be perfectly halted with medical treatments. Initially, High-Dose Cortisone (Steroid) pills or intravenous therapies are initiated to immediately silence the immune system. In the long term, to reduce cortisone reliance, immunosuppressants like Methotrexate and Azathioprine or IVIG serums are used, enabling the patient to regain their former muscle strength.