Cryptogenic Organizing Pneumonia and Idiopathic Eosinophilic Pneumonia: A Case Report of Clinically Identical Entities.

Cryptogenic organizing pneumonia (COP) and idiopathic eosinophilic pneumonia (IEP) are two forms of diffuse interstitial lung diseases (ILD) that lead to a rapid respiratory decline in young patients. Both conditions presented with similar clinical and radiological findings, making a clinical diagnosis challenging. They are both considered diagnoses of exclusion, and the treatment for both conditions is high-dose corticosteroids, leading to a quick recovery. Pathological specimens are often required prior to initiating appropriate treatment, leading to significant delays in appropriate therapy and a poorer prognosis. In this case report, we suggest that clinical pearls can be used to establish either diagnosis earlier, which leads to earlier treatment and better outcomes. Our patient presented with an acute respiratory distress syndrome (ARDS) picture, bilateral interstitial infiltrates with peripheral predominance, eosinophilia, and a negative initial infectious and cardiac workup. Based on these findings, we had a high initial suspicion that either COP or IEP was present. Our patient had a bronchoscopy done and was promptly started on steroid therapy soon after, which led to rapid clinical improvement. Pathological specimens were inconclusive, but the patient continued to improve, thereby confirming the presence of either form of ILD. The patient was subsequently discharged home with oxygen and recommended to follow up with a pulmonologist for further outpatient testing and management.