Granulomatosis With Polyangiitis Mimicking Giant Cell Arteritis.

Granulomatosis with polyangiitis (GPA) is a rare auto-immune ANCA-associated small-vessel vasculitis characterized by necrotizing granulomatous inflammation, primarily affecting the sinuses, respiratory tract, and kidneys. Early diagnosis and treatment are crucial for improving patient outcomes and preventing rapidly progressive renal failure. We present a case of a 66-year-old woman presenting to the emergency department (ED) with a two-week history of productive cough, nausea, fevers, and headache.