Unveiling the Uncommon: A Case of Eosinophilic Granulomatosis With Polyangiitis Featuring Atypical Presentation and Diagnostic Challenges

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare necrotizing vasculitis affecting small- to medium-sized vessels that can manifest in a multisystemic manner. While the classic triad of rhinosinusitis, asthma, and eosinophilia is commonly associated, it is essential to recognize that these features are not mandatory for diagnosis. We present a case of a 61-year-old woman with a unique EGPA manifestation who was hospitalized because of a seven-month history of weight loss, asthenia, epigastric abdominal pain, peripheral eosinophilia, and paresthesia in the left feet and hand. Notably absent were typical pulmonary alterations such as asthma or nasal polyps. Respiratory function tests yielded normal results, and imaging studies revealed no granulomas or signs of vasculitis. Instead, she exhibited mononeuritis multiplex and constitutional symptoms. Diagnostic criteria were met, including positive anti-neutrophil cytoplasmic antibody (ANCA) with myeloperoxidase (MPO) pattern and severe axonal neuropathy confirmed by nerve biopsy. Treatment commenced with prednisolone and then with methotrexate. This case underscores the diversity of EGPA presentations and the importance of considering atypical symptoms for accurate diagnosis and timely intervention. Despite the absence of classic features, our comprehensive approach facilitated prompt recognition and effective management.