[A case of mesalazine-induced pleuritis with hemophagocytic findings].

A 25-year-old woman who had been receiving mesalazine for 2 weeks for ulcerative colitis presented with a nonproductive cough, high fever, and exertional dyspnea. Her chest radiograph showed bilateral pleural effusion. At first, infectious pleuritis was suspected and antibiotics were administered, but the pleural effusion increased and high fever continued. Because clinical and radiographic abnormalities markedly improved with discontinuation of mesalazine and treatment with corticosteroid, mesalazine was thought to be the cause of pleural effusion in this case. This case was thought to be of interest when we consider the onset mechanism of pleurisy by mesalazine. Mesalazine-induced pleuritis must be considered in patients who develop unexplained respiratory symptoms while taking this agent.