Peripheral Neuropathy as the Initial Presenting Feature of ANCA-Negative Eosinophilic Granulomatosis with Polyangiitis: A Case Report

Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as Churg–Strauss Syndrome, is a rare necrotizing vasculitis involving small- to medium-sized vessels, typically associated with asthma and peripheral eosinophilia. Antineutrophil cytoplasmic antibodies (ANCA) are variably present, and ANCA-negative cases often pose a diagnostic challenge. We report a case of a 34-year-old female with a history of recurrent sinusitis since childhood and bronchial asthma, who presented with features of peripheral neuropathy. Laboratory evaluation revealed marked eosinophilia, while ANCA serology was negative. Histopathological examination of sural nerve demonstrated eosinophilic infiltration with vasculitis in perineural tissue, perivascular infiltration by mononuclear cells and eosinophils, fibrinoid necrosis of vessel walls, and loosely formed granulomas. Scattered epithelioid cells were noted, with negative Ziehl–Neelsen and Fite stains for acid-fast bacilli. Based on clinical, laboratory, and histopathological findings, a diagnosis of ANCA-negative EGPA was established. This case highlights the importance of recognizing peripheral neuropathy as an early manifestation and emphasizes the critical role of histopathology in establishing the diagnosis in seronegative cases. Early diagnosis is essential to initiate appropriate therapy and prevent disease progression.