(1193) Unveiling the Uncommon: Tigecycline-Induced Acute Eosinophilic Pneumonia

Introduction: Acute eosinophilic pneumonia (AEP) is a rare lung disease characterized by significant accumulations of infiltrating eosinophils in the alveolar space and interstitium manifesting as an abrupt onset of dyspnea and nonspecific symptoms with bronchoalveolar lavage (BAL) fluid analysis with eosinophil predominance. Tigecycline, a glycylcycline antimicrobial agent developed to combat multidrug-resistant pathogens, is approved for treating bacterial pneumonia. This report discusses a rare case of AEP attributed to the Tigecycline administration.

Description: A 25-year-old male with a complicated medical history, including traumatic cardiac arrests with resuscitative thoracotomy, hemopneumothorax requiring left lung lobe resection, and tracheostomy decannulation presented with bilateral posterior globe hemorrhage and worsening bilateral dry gangrene of multiple toes necessitating trans metatarsal amputation. Metatarsal osteomyelitis complicated the postoperative course, with cultures showing Klebsiella pneumonia and Candida auris. Given previous infections with multiple drug-resistant organisms, tigecycline was initiated. On the 28th day of tigecycline therapy, the patient experienced acute hypoxic respiratory failure, necessitating ICU admission and intubation. CT angiogram of the chest revealed diffuse patchy nodular and ground glass infiltrates, intralobular septal thickening, and extensive lymphadenopathy. Bronchoscopy was performed, and the BAL fluid culture yielded multiple drug-resistant Acinetobacter baumannii. Notably, BAL cell count demonstrated 99% and 100% eosinophils with minimal peripheral eosinophilia, confirming a diagnosis of AEP. Consequently, the antibiotic regimen was changed to cefiderocol for the remainder of the treatment. Over the course of two months, a prednisone taper was initiated, resulting in the improvement of the patient's symptoms and imaging findings.

Discussion: AEP is often misdiagnosed as ARDS or hospital-acquired pneumonia, emphasizing the significance of thorough evaluation, including a review of past medication use, to establish an accurate diagnosis. Clinicians should have a high suspicion of drug-induced AEP, particularly in patients with a complex medical history and exposure to medications known to be associated with this condition.