bone, joint, and muscle disorders
Microscopic Polyangiitis
Introduction
Microscopic polyangiitis is inflammation of mainly small blood vessels throughout the body. Symptoms vary depending on which organs are affected. People have a fever, lose weight, and have achy muscles and joints, as well as various other symptoms. Blood and urine tests are done, and biopsy is done to confirm the diagnosis. Treatment depends on disease severity but includes corticosteroids and drugs that suppress the immune system. (See also Overview of Vasculitis .) Microscopic polyangiitis is rare. It can occur at any age. The cause of microscopic polyangiitis is unknown. People with this disorder usually have abnormal Antibodies called antineutrophil cytoplasmic antibodies in their blood. 