Hypereosinophilia: Clinical Presentations and Diagnostic Distinction between Syndromic and Reactive Entities - A Case...

Hypereosinophilic syndrome (HES) is a heterogeneous group of disorders characterized by sustained eosinophilia and multi-organ involvement resulting from eosinophil-mediated tissue injury. The condition may arise from diverse etiologies, including clonal myeloproliferative disorders, autoimmune diseases, infections, and idiopathic causes, posing significant diagnostic challenges.

To describe and analyze the varied clinical manifestations, etiologies, and outcomes of patients presenting with hypereosinophilia in a tertiary-care setting.

This case series includes five patients with persistent eosinophilia (absolute eosinophil count >1500 cells/μL) who presented with distinct systemic manifestations. All patients underwent detailed clinical, laboratory, and imaging evaluations to determine the underlying cause and extent of organ involvement.

The clinical presentations were highly variable, including cerebral infarcts due to HES-related vasculopathy, disseminated fungal infection with lymph node and bone marrow eosinophilia, ANCA-associated vasculitis with neuropathy, bronchial asthma with marked eosinophilia, and eosinophilic gastrointestinal and hepatic disease. Corticosteroid therapy was the mainstay of treatment, supplemented with antifungal and immunosuppressive agents when indicated. Most patients showed significant improvement, though one had residual neurological deficits.

Hypereosinophilia can manifest through diverse pathophysiological mechanisms affecting nearly any organ system. Early recognition, exclusion of secondary causes, and timely initiation of corticosteroids or targeted therapies are essential to prevent irreversible organ damage and improve clinical outcomes.