A Case of Daptomycin-Induced Eosinophilic Pneumonia and Its Management Insights

Pulmonary infiltrates, arising from diverse etiologies such as infections, cardiac conditions, or parenchymal diseases, present a diagnostic challenge. Drug-induced pneumonitis, although less common, should be considered, especially when symptoms develop after medication initiation. This case report highlights a rare yet significant complication of antibiotic therapy, daptomycin-induced eosinophilic pneumonia (DIEP). A 56-year-old male with a history of type 2 diabetes mellitus, hypertension, and renal insufficiency presented with pleuritic chest pain and a productive cough for two days. Chest X-ray and CT imaging revealed bilateral scattered airspace opacities and ground-glass opacities, suggesting pneumonia or pulmonary edema. Initially treated for healthcare-associated pneumonia, the patient's condition persisted despite therapy. His medical history included osteomyelitis treated with vancomycin, later switched to daptomycin. Two weeks after the switch, the patient developed new respiratory symptoms. A bronchoalveolar lavage (BAL) was performed to establish the diagnosis of eosinophilic pneumonia. BAL showed >25% eosinophils, confirming daptomycin-induced eosinophilic pneumonia. The antibiotic was discontinued, and prednisone 40 mg daily was initiated, leading to the resolution of symptoms. Daptomycin, an antibiotic commonly used to treat gram-positive infections, can rarely cause eosinophilic pneumonia, a rare adverse reaction characterized by pleuritic chest pain, dyspnea, and diffuse ground-glass opacities on imaging. The mechanism remains unclear but may involve surfactant binding, leading to alveolar epithelial injury. Diagnosis is confirmed through BAL, with eosinophilia greater than 25%. Management consists of discontinuing daptomycin and initiating steroids if necessary. This case underscores the importance of early recognition and prompt discontinuation of the offending drug, along with the use of steroids in cases with severe symptoms. BAL is a key diagnostic tool in confirming drug-induced eosinophilic pneumonia. In conclusion, daptomycin-induced eosinophilic pneumonia is a rare but significant complication requiring vigilance in patients treated with the drug. Early diagnosis and effective management are crucial for achieving favorable outcomes.