A Case of Challenging Polyarteritis Nodosa With Critical Limb Ischemia.

Polyarteritis nodosa (PAN) is a systemic vasculitis with necrotizing inflammation of medium and small-sized arteries. Critical limb ischemia is a rare complication of PAN. We present a case report of a 64​-year-old male who presented initially with constitutional symptoms, cutaneous lesions and bilateral orchitis. After admission, he developed critical ischemia of his right lower limb with milder ischemia in his other limbs. After failure to respond to intravascular thrombolysis, he ultimately required a right below-knee amputation. He had symptoms and signs of mononeuritis multiplex and developed clinical and radiological features of severe bilateral lower limb myositis. A diagnosis of PAN was suspected, and he was commenced on treatment with high-dose corticosteroids, pulsed intravenous cyclophosphamide, intravenous immunoglobulin and intravenous heparin. His recovery was complicated by a pontine stroke and a myocardial infarction. An angiogram of the right lower limb showed arterial occlusion below the knee. A CT angiogram showed splenic and renal infarcts. The ulnar arteries were occluded in the proximal forearms. His C-reactive protein was 344 at its peak and fell to <5 with treatment. Our case report highlights an aggressive systemic presentation of PAN with extensive organ involvement including critical lower limb ischemia, cutaneous vasculitis, orchitis, mononeuritis multiplex, myositis and infarcts affecting brain, myocardium, kidneys and spleen.