Acute Eosinophillic Pneumonia Introduction

  • rare disease inflammatory disease of the small airways and alveoli
  • characterized by eosinophilic infiltration of the pulmonary parenchyma (alveoli and interstitium)
  • Cause
    • unknown
      • ?acute hypersensitivity reaction to an unidentified inhaled antigen in an otherwise healthy individual
        • smoke
          • cigarettes
          • marijuana
          • electronic cigarettes
          • water pipe cigarettes
          • cocaine and other drugs
          • immune therapy
  • result
    • Structural
      • extensive disease
      • eosinophils
        • marked numbers of interstitial eosinophils
        • lesser numbers of alveolar eosinophils
      • intraalveolar fibrinous exudate (100 percent of cases),
      •  perivascular and intramural inflammation without necrosis
      • DAD
        • hyaline membranes
        • edema
        • fibrosis
  • Clinical
    • acute/subacute illness of
      • less than four weeks duration
      • cough
      • dyspnea
      • fever (often high)
      • may require ventilation
  • LAb
    • leukocytosis
    • eosinophils not initially  but
      • becomes markedly elevated subsequently
    • IgE elevated
    • Some ANCA positive
    • some positive sputum eosinophilia
  • At the onset
  • Radiology
    • diffuse disease
      • unlike chronic eosinophilic pneumonia, in which the opacities are typically localized to the lung periphery.
    •  CXR
      • early chest radiograph
        • subtle reticular or ground glass opacities,
          • Kerley B lines
      • evolving
        • ground glass
        • bilateral diffuse diffuse parenchymal opacities
    • CT
      • bilateral, random, and patchy ground-glass or reticular opacities
      • centrilobular nodules and air-space consolidation are seen in approximately 50 and 40 percent, respectively