Fatal Misdiagnosis: Anca-associated Vasculitis Presenting as Guillain–Barre Syndrome

Abstract Medium and small arteries are affected by anti-neutrophilic cytoplasmic antibody-associated vasculitis (AAV), a systemic necrotizing inflammatory illness, that commonly causes peripheral neuropathy in the form of mononeuritis multiplex. There are three types of clinical subtypes in AAV, (1) microscopic polyangitis (MPA); (2) granulomatosis with polyangitis; (3) eosinophilic granulomatosis with polyangitis. We are presenting one case of fulminant neuropathy with AAV mimicking Guillain–Barre Syndrome, which is a rare occurrence. Rapid and early differentiation between the two conditions is important. In our case, we could not initiate the treatment due to suspected sepsis, which was later on found to be caused by the acute inflammatory response of systemic vasculitis. Once the diagnosis was clear, it was already late, and we lost the patient. The presence of a systematic inflammatory response, multiple organ dysfunctions, thrombocytosis, and normal procalcitonin can differentiate the two conditions, and emergent plasmapheresis would have been life-saving.