Fatal diffuse alveolar haemorrhage mimicking acute exacerbation in idiopathic pulmonary fibrosis treated with nintedanib

A 75‐year‐old man was referred to our hospital with a 1‐year history of persistent dry cough and progressive dyspnoea on exertion. He was treated with aspirin due to thrombosis of internal carotid artery. He was diagnosed with idiopathic pulmonary fibrosis ( IPF )/usual interstitial pneumonia ( UIP ), and started on inhaled N ‐acetylcysteine therapy and pirfenidone. Since his clinical condition progressively deteriorated after 6 months, he was switched from pirfenidone to nintedanib. As a result, his general condition worsened rapidly. He was diagnosed with acute exacerbation ( AE ) of IPF , and was treated with methylprednisolone pulse and recombinant human soluble thrombomodulin. Despite the administration of these treatments, he died of severe haemoptysis four days after the onset of AE . Autopsied lungs revealed significantly dark red‐brown appearance corresponding to diffuse alveolar haemorrhage ( DAH ) histopathogically with a background pattern of UIP with fibrotic change. Notably, there was no evidence of diffuse alveolar damage suggesting IPF‐AE .