What is the cause of a cough with eosinophilia (elevated eosinophil count)?

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Last updated: April 30, 2025 • View editorial policy

Differential Diagnosis for Cough and Eosinophilia

Single Most Likely Diagnosis

  • Asthma: This is the most likely diagnosis due to the common association of cough with eosinophilia, which is a hallmark of allergic reactions and asthma. Eosinophils play a key role in the inflammatory process of asthma.

Other Likely Diagnoses

  • Allergic Bronchopulmonary Aspergillosis (ABPA): This condition often presents with cough, eosinophilia, and is associated with asthma. It's caused by an allergic reaction to Aspergillus fungi.
  • Parasitic Infections: Certain parasitic infections like hookworm, roundworm, or tapeworm can cause eosinophilia and cough, especially if the parasites infect the lungs.
  • Hypereosinophilic Syndrome (HES): A group of disorders characterized by the overproduction of eosinophils, which can lead to cough among other symptoms due to the involvement of various organs including the lungs.

Do Not Miss Diagnoses

  • Löffler's Syndrome: Also known as simple pulmonary eosinophilia, it's characterized by migratory pulmonary infiltrates accompanied by eosinophilia. It's crucial to diagnose as it can resolve spontaneously but may require treatment.
  • Churg-Strauss Syndrome (Eosinophilic Granulomatosis with Polyangiitis, EGPA): A form of vasculitis that can present with cough, eosinophilia, and asthma. It's life-threatening if not treated promptly.
  • Tropical Pulmonary Eosinophilia (TPE): A condition seen in the tropics, associated with parasitic infections, characterized by cough, eosinophilia, and pulmonary infiltrates.

Rare Diagnoses

  • Eosinophilic Pneumonia: A rare condition characterized by the accumulation of eosinophils in the lungs, which can cause cough and eosinophilia.
  • Idiopathic Eosinophilic Chronic Pneumonia: A rare condition with unknown cause, characterized by chronic cough and eosinophilia, often responsive to corticosteroid treatment.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.