title: Acute Eosinophilic Pneumonia: Correlation of Clinical Characteristics With Underlying Cause.
abstract: Acute eosinophilic pneumonia (AEP) is an uncommon disease, often indistinguishable from ARDS or community-acquired pneumonia at initial presentation. AEP can be idiopathic, but identifiable causes include medications and inhalational exposures, including cigarette smoke.
  
  
  
  Using a computer-assisted search, we retrospectively identified and reviewed the medical records of all patients diagnosed with AEP between January 1, 1998, and June 30, 2016, at our institution. Demographic and clinical data were extracted, including exposures (occupational, environmental, recreational, pharmacologic, and smoking), laboratory and radiologic findings, treatments, hospitalization (including ICU stay), and subsequent clinical course.
  
  
  
  Among 36 consecutive patients with AEP, 11 were smoking-related cases, six were medication-related cases and 19 were idiopathic. Smoking-related AEP included six first-time smokers and five ex-smokers who had resumed smoking after a period of abstinence. Patients with smoking-related AEP were younger compared with both medication-related and idiopathic AEP cases (median age: 22 vs 47.5 vs 55 years, respectively; P = .004). Patients with smoking-related AEP were less likely to be associated with peripheral eosinophilia at presentation (36% vs 50% vs 58%; P = .52) but more likely to be hospitalized (100% vs 50% vs 63%; P = .039), including a longer ICU stay, compared with medication-related and idiopathic cases.
  
  
  
  AEP is associated with a good prognosis when recognized and treated promptly. Compared with medication-related and idiopathic AEP, smoking-related AEP was less likely to be associated with peripheral eosinophilia at presentation but was characterized by more severe disease manifestations.
authors.affiliation: Dipartimento Cardio-Toraco-Vascolare, University of Milan-Bicocca, Respiratory Unit, San Gerardo Hospital, Monza, Italy; Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Federica
authors.initials: F
authors.lastname: De Giacomi
authors.affiliation: Health Sciences Research, Mayo Clinic, Rochester, MN.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Decker
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Robert
authors.initials: R
authors.lastname: Vassallo
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN. Electronic address: ryu.jay@mayo.edu.
authors.forename: Jay H
authors.initials: JH
authors.lastname: Ryu
mesh_terms: D000208:Acute Disease; D000284:Administration, Oral; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D003422:Critical Care / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000627:therapeutic use; D011241:Prednisone / Q000008:administration & dosage; D011657:Pulmonary Eosinophilia / Q000209:etiology* / Q000628:therapy; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D010100:Oxygen; D011241:Prednisone
keywords: acute eosinophilic pneumonia; eosinophilia; mechanical ventilation; tobacco smoke