Multiple jeopardy: Diagnostic and therapeutic challenges in vasculitic flare

A 57-year old gentleman had presented a year back with inflammatory oligoarthritis and vasculitic neuropathy, diagnosed as unclassifiable vasculitis, initiated on oral corticosteroids and intravenous cyclophosphamide (monthly X 6). His disease stabilized and he had been maintained on azathioprine, which had to be stopped due to acute pancreatitis with subsequent pseudocyst formation, requiring percutaneous drainage suspecting infection. Within a week of pseudocyst drainage, he developed sudden onset pain in left upper limb, with absent left upper limb pulses, loss of motor function of left hand, myocardial ischemia, and extensive thrombosis of the left upper limb arteries. Neuropathy in the left upper limb was either vasculitic, or ischemic due to arterial thrombosis. However, multifocal thrombosis suggested an ongoing vasculitic flare. In view of possible infected pancreatic pseudocyst, intravenous methylprednisolone pulse was contra-indicated. Hence, he was offered intravenous immunoglobulin (IVIG) therapy, despite the risk of potentially worsening the prevalent prothrombotic state. On the second day of IVIG, he developed transiently tingling and weakness of right hand with vasculitic rashes, which subsequently resolved, reaffirming the suspicion of vasculitic flare. After completing IVIG therapy, the weakness in his left hand had markedly improved. His myocardial ischemia had also recovered, with a repeat echocardiography showing normalization of prior left ventricular hypokinesia. In the intervening period, the pseudocysts were drained, following which he was initiated on rituximab. This case highlights numerous challenges in the initial diagnosis, distinguishing vasculitic from ischemic neuropathy, and the management of vasculitic flare during infection.