A 75-year-old woman with acquired haemophilia disguised by warfarin treatment.

Acquired haemophilia is a rare coagulation disorder more commonly seen in elderly patients. Diagnosis and effective treatment can be delayed if patients are on warfarin treatment, as the bleeding symptoms may be erroneously attributed to this agent. We present a case report of a 75-year-old woman whose unexplained, severe and persistent bleeding was treated with surgical decompression and plasma transfusions, an appropriate management based on the assumption that warfarin was the cause of the bleeding. It was only when the patient's international normalised ratio returned to normal that a persistent abnormal activated partial thromboplastin time was noted. This delayed the correct diagnosis and treatment. Awareness of acquired haemophilia as a possible cause of sudden bleeding should be encouraged, and the wider dissemination of any relevant experience of similar cases would also be welcome. 2015 BMJ Publishing Group Ltd.