Polyarteritis nodosa (PAN)

Classical PAN is a multisystem disorder. Aneurysmal dilatation of medium-sized arteries may be seen on renal arteriography. The condition is more common in men and in the elderly and, typically, the patient is ANCA-negative. Hypertension and haematuria occur and renal failure is common.

Clinical Features of Polyarteritis nodosa (PAN)

These include fever, malaise, weight loss and myalgia. These initial symptoms are followed by dramatic acute features that are due to organ infarction.

• Neurological - mononeuritis multiplex is due to arteritis of the vasa nervorum.
• Abdominal - pain due to arterial involvement of the abdominal viscera, mimicking acute cholecystitis, pancreatitis or appendicitis. Gastrointestinal haemorrhage occurs because of mucosal ulceration.
• Renal - presents with haematuria and proteinuria. Hypertension and acute/chronic renal failure occur.
• Cardiac - coronary arteritis causes myocardial infarction and heart failure. Pericarditis may occur.
• Skin - subcutaneous haemorrhage and gangrene occur. A persistent livedo reticularis is seen in chronic cases. Cutaneous and subcutaneous palpable nodules occur, but are uncommon.
• Lung - involvement is rare.

Treatment of Polyarteritis nodosa (PAN)

Treatment is with corticosteroids, usually in combination with immunosuppressive drugs such as azathioprine.