Polyarteritis Nodosa

Polyarteritis Nodosa is a rare disease that causes inflammation of the medium-sized arteries in the body. This inflammation can lead to damage in various organs by reducing blood flow, which may cause pain, weakness, or organ dysfunction. The condition primarily affects the blood vessels, which are responsible for carrying oxygen-rich blood to tissues. Common symptoms include fever, weight loss, and muscle or joint pain. Because it can affect many different organs, symptoms vary widely depending on which arteries are involved. Early diagnosis is important to prevent serious complications such as organ failure.

Polyarteritis Nodosa (PAN) is a systemic necrotizing vasculitis characterized by transmural inflammation of medium-sized muscular arteries, leading to fibrinoid necrosis and aneurysm formation. The pathogenesis often involves immune complex deposition, sometimes associated with chronic infections like hepatitis B virus. PAN spares small vessels such as arterioles, capillaries, and venules, distinguishing it from other vasculitides. Clinically, it presents with multisystem involvement including skin lesions, peripheral neuropathy, renal ischemia without glomerulonephritis, and gastrointestinal symptoms. The disease is significant due to its potential to cause organ ischemia and infarction, leading to morbidity and mortality if untreated. Diagnosis relies on clinical features, angiographic findings of microaneurysms, and histopathology showing necrotizing arteritis.