Case Presentation: A 77-year-old man with spondylolisthesis, status post L4-S1 fusion surgery, presented for wound dehiscence and surgical site infection. He underwent incision and drainage with cultures growing S Epidermidis. Given the patient’s medication allergies and intolerances, infectious diseases (ID) was consulted with plan for a 6-week course of daptomycin. Thirteen days into the treatment, the patient re-presented with fever, dyspnea, cough, increasing oxygen requirement, and chest x-ray findings of multifocal consolidations consistent with atypical pneumonia. ID was re-engaged and started empiric ertapenem and azithromycin. Respiratory status and oxygenation worsened, requiring escalation to the intensive care unit (ICU) for non-invasive positive pressure ventilation and later high flow nasal canula requiring between 70% to 100% FIO2. Despite this regimen, his respiratory status failed to improve. Three weeks into treatment, the ICU considered a diagnosis of daptomycin eosinophilic pneumonitis based on persistent multifocal consolidations and also fibrosis on CT imaging. His oxygen requirement precluded diagnostic bronchoscopy. Methylprednisolone 125mg twice daily was started, and daptomycin was discontinued in favor of linezolid for spinal surgical site infection management. Within 10 days, the patient was weaned to 6 liters nasal canula. Methylprednisolone dose was decreased to 75mg daily and tapered off over 6 weeks.
Discussion: In this case report, we present a rare instance of daptomycin eosinophilic pneumonitis, a potentially life-threatening antibiotic complication. In most cases, these patients develop sudden onset of dyspnea, hypoxemia, and bilateral infiltrates on chest imaging shortly after initiation of daptomycin therapy. In > 51% of cases, eosinophil count on bronchoalveolar lavage is >25%. The timing of symptom onset, exclusion of other etiologies, and resolution of symptoms after discontinuation of daptomycin and initiation of steroids support the diagnosis of daptomycin eosinophilic pneumonitis. Its mechanism is not well understood but may involve direct lung toxicity or an immune-mediated response. Early diagnosis is critical, as prompt daptomycin withdrawal and supportive management, including mechanical ventilation, if necessary, relate to improved outcomes.
Conclusions: This case highlights the rare but serious risk of daptomycin eosinophilic pneumonitis, emphasizing the need for clinical vigilance when prescribing this antibiotic. Early recognition and management were key to the favorable outcome. Further research is needed to understand the pathophysiology, risk factors, and preventive measures associated with this rare but serious side effect.