Isoniazid/methotrexate/ustekinumabAcute eosinophilic pneumonia: case report A 61-year-old man developed drug-induced acute eosinophilic pneumonia during treatment with isoniazid for latent tuberculosis, and ustekinumab and methotrexate for Crohn's colitis [dosages and routes not stated].The man presented with 3 weeks of shortness of breath and cough productive of occasional brown sputum. He had been receiving treatment with isoniazid for latent tuberculosis. In the past year, for Crohn colitis, he received methotrexate. Six weeks prior to the presentation, he received his first dose of ustekinumab . He had been also receiving treatment with unspecified anticoagulants, salbutamol, metformin, folic acid and various other medications. Two weeks prior to the presentation, he developed first episode of pneumonia and subsequently treated with levofloxacin. However, no significant improvement was noted in his condition. On physical examination at the time of presentation, he was alert and oriented and responding appropriately to questions. He had dry oral mucosa, regular rate and rhythm without murmurs. He was noted to be tachypnoeic and had bibasilar and right midfield crackles. Initial laboratory tests showed an elevated lactate level, leucocytosis, eosinophilia, elevated CRP and ESR. Furthermore, chest radiograph showed consolidation throughout the left mid and lower lung with new consolidation in the right upper lung and right lower lung. He was then admitted. On hospital day 01, chest CT revealed extensive multifocal nodular consolidations throughout both lungs.Subsequently, the man was treated with cefepime, metronidazole, azithromycin and vancomycin. However, his hypoxaemic respiratory failure progressed and by hospital day 6, he was requiring 100% fraction of inspired oxygen and ultimately required transfer to the ICU and intubation. On the same day, bronchoscopy with bronchoalveolar lavage (BAL) was performed, which revealed 62% eosinophils, 19% lymphocytes and 9% neutrophils. Based on these examinations, a diagnosis of acute eosinophilic pneumonia secondary to methotrexate, isoniazid and ustekinumab was made [durations of treatments to reaction onset not stated]. Therefore, his treatment with ustekinumab was stopped. He was also treated with methylprednisolone, followed by a 6 week prednisone taper. Subsequently, his respiratory status greatly improved. He was on room air by hospital day 16 and he was able to taper off of methylprednisolone and prednisone. One month after presentation, his chest CT showed significantly improved consolidations.