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Vasculitic Syndrome: Polyarteritis nodosa (PAN) Clinical Presentation:
Generalized inflammatory symptoms:
Symptoms may also relate to decreased organ blood flow:
Hypertension (due to reduced flow into the renal arteries and, thus, renin-angiotensin system activation)
Etiology & some Epidemiology:
PAN may be idiopathic (from an obscure or unknown cause).
Is also seen with Hepatitis B infection (30% of PAN cases).
Prevalence of 6/100,000 – more common in males
Many nodules found along course of vessels.
Histologic examination of affected areas of arteries shows:
PMNs in all three vessel layers (intima, media, adventitia)
Intimal proliferation and degeneration
Fibrinoid necrosis with occlusion of the lumen
Grossly, the vessel wall (including elastic lamina) is disrupted and leads to aneurismal dilatation.
Distal to the involved vessel, get ischemia that damages tissues and visceral organs; kidney, heart, liver are
Biopsy of involved vessel: used to diagnose PAN
Blood test: Antineutrophil cytoplasmic antibodies (ANCAs) circulating – suggests necrotizing vasculitis
Prednisone and other Immunosuppressive Agents (with treatment, good prognosis: 5 year prognosis of up to 80%)
If disease goes untreated, prognosis is poor (5 year = 15%)