Mesalamine induced eosinophilic pneumonia

We present the case of a twenty two year old Caucasian male with ulcerative colitis on mesalamine who presented with dry cough, fever, malaise and dyspnea on exertion. He had peripheral eosinophilia and apical ground-glass opacities on computed tomography of the chest. He had no new exposures and his infectious workup was non diagnostic. Bronchoalveolar lavage showed eosinophilia raising the suspicion of mesalamine induced eosinophilic pneumonia. His symptoms improved after discontinuing mesalamine with a tapered dose of steroids.