Eosinophilic granulomatosis with polyangiitis following flu guard influenza vaccination: A case report

Key Clinical Message This case highlights a potential association between influenza vaccination and the development of eosinophilic granulomatosis with polyangiitis (EGPA), prompting the need for increased vigilance regarding vaccine‐related autoimmune reactions. While causality remains unclear, clinicians should consider this possibility in patients presenting with EGPA‐like symptoms shortly after vaccination. Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis characterized by tissue infiltration by eosinophils and hyper eosinophilia. We present a case of EGPA in a middle‐aged man following influenza vaccination. The patient developed respiratory symptoms, skin lesions, joint pain, and neurological deficits. Diagnostic tests revealed eosinophilia, positive anti‐neutrophil cytoplasmic antibodies, and elevated acute phase reactants. This report highlights a potential association between influenza vaccination and EGPA. Leuckocytic vasculitis with eosinophilic infiltration in dermis after influenza vaccination.