MRCEM Notes

Polyarteritis nodosa

Polyarteritis nodosa (PAN) is a vasculitis affecting medium-sized arteries with necrotizing inflammation leading to aneurysm formation. PAN is more common in middle-aged men and is associated with hepatitis B infection

Features
  • fever, malaise, arthralgia
  • weight loss
  • hypertension
  • mononeuritis multiplex, sensorimotor polyneuropathy
  • testicular pain
  • livedo reticularis
  • haematuria, renal failure
  • perinuclear-antineutrophil cytoplasmic antibodies (ANCA) are found in around 20% of patients with 'classic' PAN
  • hepatitis B serology positive in 30% of patients

© Image used on license from DermNet NZ
Livedo reticularis

© Image used on license from Radiopaedia
Angiogram from a patient with polyarteritis nodosa. Both kidneys demonstrate beading and numerous microaneurysms affecting the intrarenal vessels. Similar changes are seen affecting the intrahepatic vessels with a few small microaneurysms noted. The proximal branches of the SMA appears normal; however there are no normal straight arteries from the jejunal arteries and lack of normal anastomotic arcades and loops. This is associated with multiple microaneurysms.
Full-size image