A rare case of mesalamine-induced eosinophilic pleural effusion

Abstract

We present a very rare case of a 47-year-old man with a history of ulcerative colitis (UC), referred to as a case of an undiagnosed bilateral pleural effusion. His chest X-ray and subsequent CT (computerized tomography) thorax showed bilateral pleural effusion. The pleural fluid analysis was suggestive of an exudate with 60% eosinophilia. The patient was started on mesalamine therapy for UC 3 months prior to this presentation. Mesalamine was substituted with tofacitinib, and a short course of oral corticosteroids was given. His repeat chest X-ray on follow-up showed a resolution of the effusion. The eosinophilic pleural effusion was possibly secondary to an adverse reaction to mesalamine. This is a very rare occurrence, with less than five cases reported in the literature.

Keywords

• eosinophilic pleural effusion
• mesalamine
• drug reactions