Daptomycin-Induced Eosinophilic Pneumonia

Abstract

Introduction: The known etiologies of acute eosinophilic pneumonia (AEP) have grown recently, culminating in the creation of the term drug-induced AEP 3. One of the newer causes of druginduced AEP is Daptomycin, which has grown in popularity for its use in treating methicillin-resistant staph aureus (MRSA) infections. As a result, the Food Drug Administration created the following criteria to diagnosis Daptomycin-induced AEP: 1) concurrent exposure to Daptomycin, 2) fever, 3) dyspnea with increased oxygen requirement or requiring mechanical ventilation, 4) new infiltrates on imaging, 5) bronchoalveolar lavage (BAL) with >25% eosinophils and 6) clinical improvement following Daptomycin withdrawal. Given this statement, we present a case of Daptomycin-induced AEP. Case Presentation: A 45-year old female presented to the ER with a complaint of shortness of breath for four days. She had recently been diagnosed with Covid-19 with concomitant globicatella bacteremia and discharged 17 days ago with home oxygen (requiring 3L) and to complete 2 weeks of IV Daptomycin. In the ER, a CT Angio Chest was obtained showing bilateral airspace opacities with no evidence of thromboembolism. She was also noted to be saturating at 92% while on 15L Venturi-mask. The patient was started on broad-spectrum antibiotics and cultures were obtained. Her condition worsened and a bronchoscopy with bronchoalveolar lavage (BAL) was performed, however there was inadequate specimen to run cytology. Due to worsening status despite antibiotics, the patient was started on methylprednisolone 80 mg three times a day. After initiation of steroids, the patient's respiratory status returned to baseline and repeat imaging showed improvements of opacities. Complete infectious and autoimmune workups were complete ruling out other etiologies. The patient was discharged with a steroid taper and repeat CT imaging ordered, but never done. Discussion: Though we were unable to obtain a BAL specimen, we are confident of our diagnosis. Our patient not only had a known inciting factor, but also had resolution of symptoms with withdrawal of Daptomycin and initiation of steroids. Our case study highlights two important points about the disease. First, AEP should be on the differential for patients with a complaint of shortness of breath with a known inciting factor. Secondly, it should be noted that while our patient was unable to meet all criteria created by the FDA, this should not rule out the diagnosis. It is important to be proactive in treatment if clinical suspicion is high.