Paediatrics: Polyarteritis nodosa

Polyarteritis nodosa

Rare, medium-vessel     necrotizing   vasculitis    with   aneurysm    formation.

Male:female ratio 2:1.

Clinical

• Antecedent systemic illness with unexplained fevers, abdominal pains, and arthralgia of up to 1yr.

• Testicular pain in males (often mistaken for torsion).

• Vasculitis or purpuric skin rash.

• Arthritis (30%) large joints: exquisite bony tenderness from peripheral vasculitis and periosteal new bone formation.

• Renal: hypertension; haematuria, proteinuria; renal failure; intrarenal aneurysms.

• GI involvement (50%): abdominal pain; pancreatitis; bowel infarction.

• CNS: mononeuritis multiplex; peripheral neuropathy; fits; hemiplegia.

Investigations

• FBC; LFTs may be elevated.

• Renal function urinalysis for active sediment.

• MRI; MR angiography to reveal multiple aneurysms.

• Histology: panarteritis with fibrinoid necrosis, thrombosis, infarction, weakening of artery walls, and aneurysms. Segmental lesions at bifurcations of small- and medium-vessel walls.

Course and treatment 

Without treatment may be fatal. Often under recognized and undertreated in children. If treated promptly, with pulsed cyclophosphamide and high dose steroids, prognosis improved.