Episode 62: Eosinophilia, EGPA, and the Art of Diagnostic Uncertainty with Dr. Luke Chen

In this episode of Around the Rheum, hosts Dr. Daniel Ennis and Dr. Janet Pope sit down with Dr. Luke Chen for a deep dive into an approach to patients presenting with hypereosinophilia. Recorded at the Canadian Rheumatology Association (CRA)’s 2026 Annual Scientific Meeting in Halifax, the conversation explores how hematologists, rheumatologists, allergists, infectious disease specialists, and others work together to diagnose and manage these complex disorders.Dr. Chen discusses the broad differential diagnosis behind eosinophilia — from Eosinophilic Granulomatosus with Polyangiitis (EGPA) and IgG4-related disease to parasitic infections to rare hematologic disorders to 'Idiopathic' Hypereosinophilic Syndrome (I-HES) — and the uncertainty clinicians often face when distinguishing overlapping eosinophilic diseases. The discussion also highlights emerging therapies including IL-5 inhibitors, JAK inhibitors, interferon, and biologics, alongside the practical realities of access to treatment in rare disease care.Thoughtful, practical, and candid, this episode offers insight into multidisciplinary medicine, diagnostic humility, and caring for patients living with rare inflammatory diseases. It touches on the importance of being okay with uncertainty in the rare disease space.Dr. Luke Chen is a hematologist and Professor of Medicine at Dalhousie University in Halifax, Nova Scotia. His clinical and research interests focus on rare inflammatory diseases and eosinophilic disorders. He is the founder of the Coastal Rare Inflammatory Diseases Program, supporting physicians caring for patients with rare diseases across Canada.Around The Rheum is produced by the CRA Communications Committee. A special thank you to the podcast team, Dr. Dax G. Rumsey (CRA Communications Committee Chair), Dr. Daniel Ennis (Host), Dr. Janet Pope (Host), David McGuffin of Explore Productions, and Erin Stewart (CRA) for leading production.Our theme music was composed by Aaron Fontwell.For more on the work of the Canadian Rheumatology Association, visit rheum.ca.