Parapneumonic effusion or malignancy-associated eosinophilia: This is often seen in the context of lung cancer, including adenocarcinoma, where the tumor can cause an eosinophilic reaction in the pleural fluid due to the body's immune response to the tumor.

Pulmonary embolism with infarction: Although less common, pulmonary embolism can lead to pleural effusion with eosinophilia, especially if there's associated pulmonary infarction.
Drug-induced eosinophilic pleural effusion: Certain medications can cause eosinophilic pleural effusions, and it's essential to consider the patient's medication history.
Idiopathic eosinophilic pneumonia: A rare condition characterized by eosinophilic infiltration of the lungs, which can also involve the pleura.

Acute eosinophilic pneumonia: A severe condition that requires prompt recognition and treatment. It can present with pleural effusion and eosinophilia.
Parasitic infections: Although rare in many areas, parasitic infections like paragonimiasis can cause eosinophilic pleural effusions and must be considered, especially in travelers or individuals from endemic areas.
Churg-Strauss syndrome (Eosinophilic Granulomatosis with Polyangiitis, EGPA): A form of vasculitis that can involve the lungs and cause eosinophilic pleural effusions. It's crucial to diagnose due to its potential for severe complications.

Lymphomatoid granulomatosis: A rare lymphoproliferative disorder that can involve the lungs and cause pleural effusions with eosinophilia.
Histiocytosis X (Langerhans cell histiocytosis): A rare disorder that can affect the lungs and cause pleural effusions, sometimes with eosinophilia.
Sarcoidosis: Although more commonly associated with lymphocytic pleural effusions, sarcoidosis can rarely cause eosinophilic pleural effusions.