Polymyositis is an autoimmune disease or a diffuse muscular inflammatory disease characterized by muscle weakness and myalgia. The cause is unclear.
It occurs when muscles are invaded spontaneously by white blood cells, the immune cells of inflammation. The muscles affected are those closest to the trunk or torso, resulting in severe weakness.
The main clinical manifestations are:
symmetry of proximal limbs;
cervical muscles weakness;
pharyngeal muscles weakness;
elevated serum enzymes.
The onset of polymyositis is most common in middle childhood and in the 20s, but it can also affect all age groups. Polymyositis is slightly more common in females.
Some patients have malignant tumors before the disease, and about 20% of patients have other autonomic diseases such as lupus erythematosus, scleroderma, rheumatoid arthritis, and Sjogren's syndrome.
Due to the different extent of involvement, the complications and the clinical manifestations of this disease are diversified.
Keywords: dermatomyositis polymyositis; poly dermatomyositis; polydermatomyositis; polymyositis dermatomyositis.