Polyarteritis Nodosa

Question 1

What is Polyarteritis nodosa (PAN) associated with?

Answer 1

Majority idiopathic, but may be 2’ hep B, hep C, or hairy cell leukemia

30% of patients are HBsAg +ve hence important to ask for:

• Previous Dx of Hep B
• Presentation of Hep B (yellowing, RHC pain)
• Risk Factors for Hep B: tattoos, IVDU

Question 2

What are the skin manifestations of PAN?

Answer 2

• Rash and ‘punched out’ ulcers
• SC haemorrhage, digital ischaemia and gangrene
• Tender, erythematous & palpable nodules: Palpable Purpura!
• If chronic: persistent livedo reticularis in LL

Question 3

What are the renal manifestations of PAN?

Answer 3

PC: modest haematuria, sub-nephrotic proteinuria but NO red cell casts (note: only glomerular ischaemia 2’ luminal narrowing but no inflam or necrosis)

However, no GN! Thus, no severe haematuria /proteinuria

Rapidly progressive HTN 2’ RAAS activation

Renal insufficiency -> AKI / CRF

In fact, presentation of Renal Involvement is v similar to that in SSc (but less severe!) 1) AKI 2) HTN 3) Mild/Slight Proteinuria

Question 4

What are the GIT manifestations of PAN?

Answer 4

• Mesenteric arteritis: intestinal angina, LOW -> bowel ulceration (BGIT), infarct and perf
• Intestinal Angina = intermittent pain that is more pronounced after meals (due to increased DD)
• LOW from malabsorption

Can also present with N&V, Melena, Bloody Diarrhoea

Question 5

What are the cardiovascular manifestations of PAN?

Answer 5

• Angina (overt AMI uncommon)
• Heart failure 2’ ischaemic cardiomyopathy or uncontrolled HTN
• Pericarditis

Question 6

What are the neuro manifestations of PAN?

Answer 6

Mononeuritis multiplex 2’ arteritis of vasa nervorum (70%)

• Most commonly sural, peroneal, radial, ulnar
• Often presents first with foot or wrist drop, asymmetrically
• Eventually symmetrical, involves both motor and sensory

Question 7

What are the lung manifestations of PAN?

Answer 7

Characteristically spared

Question 8

What are the investigations conducted for PAN?

Answer 8

FBC - Anaemia, leucocytosis

ESR, CRP raised

Bx of a clinically affected organ (diagnostic): fibrinoid necrosis of vessel walls (homogenous, eosinophilic appearance), with microaneurysm formation, thrombosis and infarction. Fibrinoid necrosis is a form of necrosis, or tissue death, in which there is accumulation of amorphous, basic, proteinaceous material in the tissue matrix with a staining pattern reminiscent of fibrin

Angiography: microaneurysms in hepatic, mesenteric or renal vessels

Question 9

What is the management of PAN?

Answer 9

• Mild (constitutional symptoms and skin lesions): GC only
• Moderate to severe: GC + CP/AZT
• If hep B, C -> give anti-virals