Definition of Polyarteritis nodosa:

Polyarteritis nodosa is a serious blood vessel disease in which small and medium-sized arteries become swollen and damaged.

Causes, incidence, and risk factors:

Polyarteritis nodosa is a disease of unknown cause that affects arteries, the blood vessels that carry oxygenated blood to organs and tissues. It occurs when certain immune cells attack the affected arteries.

More adults than children get this disease. It damages the tissues supplied by the affected arteries because the tissues aren't receiving the oxygen and nourishment they need.

In this disease, symptoms result from damage to affected organs, often the skin, heart, kidneys, and nervous system.

Generalized symptoms include fever, fatigue, weakness, loss of appetite, and weight loss. Muscle and joint aches are common. The skin may show rashes, swelling, ulcers, and lumps.

Nerve involvement may cause sensory changes with numbness, pain, burning, and weakness. Central nervous system involvement may cause strokes or seizures. Kidney involvement can produce varying degrees of renal (kidney) failure.

When heart arteries are involved, heart attack, heart failure, and inflammation of the sack around the heart (pericarditis) can occur.