Unilateral balsalazide-induced eosinophilic pneumonia in an ulcerative colitis patient

We report a case of unilateral eosinophilic pneumonia secondary to balsalazide monotherapy for ulcerative colitis. After commencing balsalazide, the patient presented with a history of cough, progressive dyspnoea and lethargy. Blood counts revealed peripheral eosinophilia. Her chest radiograph showed leftsided infiltration, and high-resolution computerised tomography demonstrated widespread nodular shadowing and ground glass opacifiction in the left lung. The right lung was normal. Transbronchial lung biopsy confirmed eosinophilic pneumonia.