MEDICAL DISCLAIMER:The contents are under continuing development and improvements and despite all efforts may contain errors of omission or fact. This is not to be used for the assessment, diagnosis or management of patients. It should not be regarded as medical advice by healthcare workers or laypeople. It is for educational purposes only. Please adhere to your local protocols. Use the BNF for drug information. If you are unwell please seek urgent healthcare advice. If you do not accept this then please do not use the website.

Polyarteritis Nodosa

Learning objectives

  • Learning
  • Understand
  • Integrate
  • Reflect


Polyarteritis Nodosa is a rare systemic necrotising vasculitis of medium-sized arteries without the involvement of smaller vessels. It often affects the kidney, skin, nerves, gut and muscles and joints as well as they heart and the eye but often spares the lung. It may be associated with hepatitis virus infection and hairy cell leukaemia. Only about 20% have any cerebral involvement.

  • Incidence varies from 20-40 cases per Million per annum.
  • PAN affects men more frequently than women.
  • Can occur at all ages but commonest at age of 45-65 years.
  • Systemic illness, myalgia, sudden unexplained weight loss, fever, arthritis
  • Peripheral vascular disease.
  • A polyneuropathy.
  • Abdominal pain/ Testicular pain
  • Ischaemic and haemorrhagic strokes
  • 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
Livedo reticularis

  • FBC, U&E, ESR, CRP, Vasculitis screen
  • Hepatitis B/C serology
  • Brain imaging CT/MRI/MRA and DSA when needed
  • Biopsies classically show necrotising granulomatous inflammation.
Differential depends on manifestation
  • Inflammatory bowel disease
  • 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.