Acute Eosinophilic Pneumonia. Causes, Diagnosis, and Management

Abstract

Acute eosinophilic pneumonia (AEP) is an uncommon acute respiratory illness of varying severity that includes presentation as acute respiratory distress syndrome with fatal outcome. AEP may be idiopathic, but identifiable causes include smoking and other inhalational exposures, medications, and infections. The pathogenesis of AEP is poorly understood but likely varies depending on the underlying cause. Airway epithelial injury, endothelial injury, and release of IL-33 are early events that subsequently promote eosinophil recruitment to the lung; eosinophilic infiltration and degranulation appear to mediate subsequent lung inflammation and associated clinical manifestations. Crucial for the diagnosis are the demonstration of pulmonary eosinophilia in the BAL fluid and the exclusion of other disease processes that can present with acute pulmonary infiltrates. Although peripheral blood eosinophilia at initial presentation may be a clue in suggesting the diagnosis of AEP, it may be absent or delayed, especially in smoking-related AEP. Optimal management of AEP depends on the recognition and elimination of the underlying cause when identifiable. The cessation of the exposure to the inciting agent (e.g., smoking), and glucocorticoids represent the mainstay of treating AEP of noninfectious origin. If AEP is recognized and treated in a timely manner, the prognosis is generally excellent, with prompt and complete clinical recovery, even in those patients manifesting acute respiratory failure.

Vaping Is Not Safe: A Case of Acute Eosinophilic Pneumonia following Cannabis Vapor Inhalation

“…ere is no consensus on the diagnostic criteria for AEP. e modified Philit Criteria [1,10,11] used to diagnose AEP include: (1) Acute respiratory illness of less than 1-month duration. (2) Pulmonary infiltrates on chest imaging.…”

“…Acute eosinophilic pneumonia (AEP) is a rare cause of acute hypoxic respiratory failure. e exact pathophysiology is unknown, but it is thought to involve activation of the inflammation cascade resulting in recruitment of inflammatory cells predominantly, eosinophils to the lung parenchyma [1]. ere have been reports associating this disease entity with exposure to drugs, dust, and cigarette smoking [2][3][4][5][6].…”

Acute Eosinophilic Pneumonia: A Rare Complication of Daptomycin Therapy

“…Acute eosinophilic pneumonia is a pulmonary condition characterized by eosinophilia of pulmonary secretions, which may be idiopathic or induced by various exposures, including drugs, infections, and smoking [10]. In the case of daptomycin-induced AEP, it is thought that the accumulation of the drug within a pulmonary surfactant plays a key role in the induction of an inflammatory reaction [6].…”

Acute eosinophilic pneumonia associated with smoking: a case report

“…It is characterized as a febrile illness associated with acute onset respiratory failure, bilateral diffuse pulmonary infiltrates on imaging and eosinophils >25% on BAL or lung biopsy. All other causes of pulmonary eosinophilia need to be ruled out before AEP is diagnosed [2]. …”

“…What makes our case report interesting is that in the past few years, the so-called IAEP has been found to be strongly associated with tobacco smoke exposure which can be recent initiation of smoking, change in smoking habits such as re-introduction or even short-term passive smoking [3]. The pathogenesis of smoking induced AEP is not well understood till now although it is hypothesized to occur due to respiratory epithelial injury with subsequent eosinophil recruitment, degranulation and inflammation [2]. We believe that AEP was secondary to cigarette use in our patient who had recently started smoking.…”