Recognition of the unique bleeding pattern and laboratory findings in acquired haemophilia A facilitates prompt treatment of a life-threatening disorder.

Acquired haemophilia A (AHA) is an uncommon but severe acquired bleeding disorder caused by the development of antibodies against clotting factor VIII, impairing secondary haemostasis. It is more common in older individuals and characteristically presents with spontaneous soft tissue bleeding that can rapidly become life-threatening. Definitive treatment requires immunosuppression to eradicate anti-FVIII antibodies, while providing haemostatic support to manage bleeding. Transfusions of fresh frozen plasma or cryoprecipitate, typically used to treat severe bleeding, are ineffective in patients with AHA. Instead, highly specialised clotting factor concentrates are required. While the appearance and extent of the soft tissue bleeding and the markedly prolonged activated partial thromboplastin time are characteristic, lack of familiarity with this disease process can lead to significant treatment delays. We report the clinical course and management of a 65-year-old woman who presented with severe anaemia of unclear aetiology with unrecognised soft tissue bleeding who was subsequently diagnosed with AHA.