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Polyarteritis Nodosa


  • This a systemic necrotising vasculitis of medium-sized arteries without the involvement of smaller vessels.
  • It may be associated with hepatitis virus infection.
  • Only about 20% have any cerebral involvement.


  • Patients have typical systemic illness, myalgia, weight loss, fever, arthritis
  • Peripheral ischaemic changes. They can have a polyneuropathy.
  • Ischaemic and haemorrhagic strokes as well as an encephalopathy.


PAN may be diagnosed with three of these ten criteria (82% sensitivity, 86% specificity), if other vasculitides are excluded
1 Loss of weight >4 kg
2 Livedo reticularis
3 Testicular pain
4 Myalgias
5 Mononeuritis or polyneuritis
6 Blood pressure elevation >90 mmHg
7 Creatinine >1,5 mg/dl
8 Hepatitis B or C virus antibodies
9 Pathologic arteriography (aneurysm, occlusions)
10 Typical histology finding


  • FBC, U&E, ESR, CRP, Vasculitis screen
  • Brain imaging CT/MRI/MRA
  • Biopsies classically show necrotising granulomatous inflammation.


  • Induction therapy is usually with Steroids and Cyclophosphamide.
  • Plasma exchange has been used.
  • If there is positive viral serology then appropriate antivirals against Hepatitis B or C may be given.


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