EGPA: A DIAGNOSTIC DILEMMA

Abstract

<h3>Introduction</h3> Eosinophilic granulomatosis with polyangiitis (EGPA) is a diagnostically difficult disorder due to multisystem involvement, and dual categorization with hypereosinophilic syndromes and systemic vasculitides. The early allergic phase may present in isolation for years prior to eosinophilic organ infiltration and vasculitis, highlighting the importance of consistent screening and multidisciplinary treatment in preventing complications. <h3>Case Description</h3> A 40-year-old male with allergic rhinitis, chronic rhinosinusitis with nasal polyps, and severe persistent asthma presented with peripheral eosinophilia (maximum 2950/μL) and uncontrolled asthma. Workup of secondary causes of hypereosinophilia was unrevealing. Sinus CT revealed extensive mucosal thickening with near complete opacification and lung CT showed bilateral lung ground-glass opacities admixed with consolidative opacities. Patient underwent endoscopic sinus surgery and bronchoscopy with biopsies failing to show signs of granulomata/vasculitis or eosinophilic infiltration. Evaluation of pertinent biomarkers and echocardiogram were also unrevealing. Despite this, given the concerning constellation of symptoms and a positive rheumatoid factor, EGPA remained on the differential with possibility of biopsy sampling error and seronegative ANCA vasculitis. Patient was treated with prolonged steroid taper followed by benralizumab for uncontrolled severe eosinophilic asthma with only temporary relief followed by mepolizumab, the first FDA biologic agent approved for EGPA. <h3>Discussion</h3> This patient presents with multiple features concerning for EGPA. Even without a current pathologic diagnosis, EGPA presents in phases and remains high on our differential. It is crucial to continue monitoring for end organ involvement and new systemic symptoms. New biologic agents present a promising therapy resulting in increased remission and reduced glucocorticoid use.