Case Presentation: 89-year-old male with past medical history of coronary artery disease s/p PCI, Mobitz type II heart block s/p pacemaker, paroxysmal atrial fibrillation on rivoroxaban was admitted for acute hypoxic respiratory failure with progressive dyspnea and nonproductive cough for the last 2 weeks. Patient denied having any fever, chills or night sweats. He was a lifelong non-smoker without history of vaping, marijuana or illicit drugs. There was no recent history of travel, pets or exposure to tuberculosis. PMH was significant for recent history of septic arthritis of right shoulder with MSSA bacteremia s/p surgical debridement following which patient was maintained on IV daptomycin for the last 4 weeks. CBC showed leukocytosis without peripheral eosinophilia. X-ray chest showed mixed interstitial and patchy airspace opacities. Patient was admitted for presumed hospital acquired pneumonia and initially started on broad spectrum antibiotics. CT chest without contrast revealed patchy bilateral pulmonary infiltrates with areas of ground glass attenuation with small bilateral pleural effusions (Figure 1). TTE showed normal EF. COVID-19 PCR nasopharyngeal swabs were negative x2. Fiberoptic bronchoscopy with BAL showed normal endobronchial anatomy with no active bleeding. Cell count and differential revealed 49% PMN, 24% eosinophils, 15% lymphocytes, 5% monocytes. Bronchial cultures showed rare growth alpha hemolytic Streptococcus below CFU threshold generally considered significant. AFB stain and culture, MTB DNA probe, fungal culture, Aspergillus galactomannan’s, Legionella DFA, pneumocystis DFA, respiratory virus PCR panel and COVID-19 PCR was negative. Blood cultures and procalcitonin were normal. ANCA, IgE Aspergillus, Coccidioides IgM and IgG were also not detected. Daptomycin associated AEP was suspected given negative cultures and serologies for bacterial, viral, mycobacterial and fungal infections. Daptomycin was discontinued and he was started on intravenous solumedrol. Oxygen requirement during hospital course continued to worsen while on NIPPV without clinical improvement and patient refused intubation and requested to be transitioned to comfort care and eventually died.
Discussion: Acute eosinophilic pneumonia (AEP) is a rare cause of acute respiratory failure associated with drugs, chemicals or is idiopathic. Daptomycin induced AEP is an uncommon cause of drug-induced AEP. Pathophysiology involves immune mediated pulmonary epithelial cell injury resulting from daptomycin binding to pulmonary surfactant. Risk factors include chronic kidney disease, male sex, older age and longer duration of treatment. Clinical features include fever, dyspnea, cough and symptoms usually develop 2 to 4 weeks after starting daptomycin. X-ray and CT chest reveal bilateral diffuse pulmonary infiltrates ground glass opacities and/or pleural effusions. Diagnostic criteria(Table 1) does not require peripheral eosinophilia. In appropriate clinical setting >25% eosinophils in BAL is not necessary for diagnosis as evident in our patient. Management involves discontinuation of daptomycin, systemic glucocorticoids and supportive care.
Conclusions: This case report highlights the importance of early recognition of daptomyocin induced AEP and treatment with corticosteroids to reduce mortality
