Acute eosinophilic pneumonia

This code represents an inflammatory lung condition characterized by the rapid accumulation of eosinophils in the alveolar spaces and interstitium, leading to acute respiratory failure. It is an idiopathic or drug-induced reaction, distinct from chronic eosinophilic pneumonia.

Apply this code for patients presenting with sudden onset of fever, cough, dyspnea, and hypoxemia, along with diffuse pulmonary infiltrates on imaging and elevated eosinophils in bronchoalveolar lavage fluid or lung biopsy. Documentation should clearly indicate the acute nature and eosinophilic predominance.

• Differentiate from chronic eosinophilic pneumonia (J82.81) based on the acuity of onset and clinical course.
• Always review documentation for potential drug-induced etiology, as this may require an additional external cause code.
• Ensure the physician's diagnosis explicitly states "acute eosinophilic pneumonia" or provides sufficient clinical detail to support this specific diagnosis.