Polyarteritis nodosa

Polyarteritis nodosa (PAN), is a systemic necrotizing inflammation of blood vessels (vasculitis) affecting medium-sized muscular arteries, typically involving the arteries of the kidneys and other internal organs but generally sparing the lungs' circulation. Polyarteritis nodosa may be present in infants. In polyarteritis nodosa, small aneurysms are strung like the beads of a rosary, therefore making 'rosary sign' an important diagnostic feature of the vasculitis. PAN is sometimes associated with infection by the hepatitis B or hepatitis C virus. Polyarteritis nodosa (PAN), is a systemic necrotizing inflammation of blood vessels (vasculitis) affecting medium-sized muscular arteries, typically involving the arteries of the kidneys and other internal organs but generally sparing the lungs' circulation. Polyarteritis nodosa may be present in infants. In polyarteritis nodosa, small aneurysms are strung like the beads of a rosary, therefore making 'rosary sign' an important diagnostic feature of the vasculitis. PAN is sometimes associated with infection by the hepatitis B or hepatitis C virus. PAN is a rare disease. With treatment, five-year survival is 80%; without treatment, five-year survival is 13%. Death is often a consequence of kidney failure, myocardial infarction, or stroke. PAN may affect nearly every organ system and thus it can present with a broad array of signs and symptoms. These manifestations result from ischemic damage to affected organs, often the skin, heart, kidneys, and nervous system. Constitutional symptoms are seen in up to 90% of affected individuals and include fever, fatigue, weakness, loss of appetite, and unintentional weight loss. Muscle and joint aches are common. The skin may show rashes, swelling, necrotic ulcers, and subcutaneous nodules (lumps). Skin manifestations of PAN include palpable purpura and livedo reticularis in some individuals. Abdominal pain may also be seen. Nerve involvement may cause sensory changes with numbness, pain, burning, and weakness (peripheral neuropathy). Peripheral nerves are often affected and this most commonly presents as mononeuritis multiplex, which is the most common neurologic sign of PAN. Central nervous system involvement may cause strokes or seizures. Kidney involvement is common and often leads to death of parts of the kidney though kidney filtration function is often preserved. Involvement of the renal artery, which supplies the kidneys with highly oxygenated blood, often leads to high blood pressure in about one-third of cases. deposition of protein or blood in the urine may also be seen. Involvement of the arteries of the heart may cause a heart attack, heart failure, and inflammation of the sac around the heart (pericarditis). There is no association with ANCA, but about 30% of people with PAN have chronic hepatitis B and deposits containing HBsAg-HBsAb complexes in affected blood vessels, indicating an immune complex–mediated cause in that subset. Infection with the Hepatitis C virus and HIV are occasionally discovered in people affected by PAN. PAN has also been associated with underlying hairy cell leukemia. The cause remains unknown in the remaining cases; there may be causal and clinical distinctions between classic idiopathic PAN, the cutaneous forms of PAN, and PAN associated with chronic hepatitis.In children, cutaneous PAN is frequently associated with streptococcal infections, and positive streptococcal serology is included in the diagnostic criteria.