Épanchement pleural éosinophile associé à un syndrome de Churg et Strauss

Eosinophilic pleural effusion (EPE) is defined as pleural eosinophilia greater than 10%. EPE can be seen in almost all conditions that can cause pleural effusion, but some aetiologies have to be investigated due to their frequency or potential severity. The most common aetiology of EPE is the presence of air or blood in the pleural cavity. Other frequent aetiologies include bacterial pneumonia, tuberculosis, parasitic disease and certain drugs. Although often considered to be a sign of a benign condition, pleural eosinophilia may be associated with malignancies. EPE may also indicate the presence of Churg and Strauss syndrome. We report the case of a 27-year-old man, in whom the exploration of EPE led to the diagnosis of Churg and Strauss syndrome with the association of asthma, blood and alveolar eosinophilia, myopericarditis and positive antineutrophil cytoplasmic antibodies (ANCA). This case report enables us to discuss the different causes of EPE and to illustrate how it may be a manifestation of Churg and Strauss syndrome.