Cigarette smoking-induced acute eosinophilic pneumonia: A case report

RATIONALE: Acute eosinophilic pneumonia (AEP) is a rare pulmonary disease, which is characterized by diffuse pulmonary eosinophilia. The pathogenesis remains unknown. Here we report a patient with AEP following a recently acquired habit of smoking. PATIENT CONCERNS: A 21-year-old female presented with fever, dry cough, and acute hypoxic respiratory distress for 2 days. Chest computed tomography showed bilateral ground glass opacities, patchy nodules, and pleural effusions. Blood tests showed a gradually raised peripheral eosinophils level. DIAGNOSES: Bronchoalveolar lavage fluid revealed marked elevation of eosinophils. She was diagnosed with AEP. INTERVENTIONS: Systemic methylprednisolone was immediately used for treatment. OUTCOMES: Her clinical symptoms and chest radiographs improved promptly after treatment. LESSONS: Cigarette smoking might be an underlying triggering factor of AEP. Diffuse alveolar infiltrates and a gradually increasing peripheral eosinophilia should raise the concern especially in recent smoking patients.