An unusual case of Crohn's disease with unresponsive pleural exudates. Is Crohn's disease finally a systemic immunological disorder?

Crohn's disease has been infrequently associated with various respiratory manifestations. Reports of pleural effusions in Crohn's disease are even sparser, but differential diagnosis is rich, with causes either associated with the disease or being independent. Processes directly or indirectly related to therapy, entities overlapping with Crohn's disease in pathogenesis and common causes of effusions should all be considered, under the guidance of laboratory testing and imaging. We report here an unusual case of bilateral pleural effusions unresponsive so far to medical therapy, in a patient with long-standing Crohn's disease and several features of autoimmunity. A short review of the literature is presented, the differential diagnosis is outlined and the systemic immunological profile of Crohn's disease is discussed.