Acquired factor VIII inhibitor in a non-haemophilic boy

We describe the case of a previously healthy 8-year-old non-haemophilic boy who developed a factor VIII inhibitor of unknown origin. The symptoms of this disease were haemorrhages in the muscles of the right thigh, numerous bruises and a large haematoma of the right crus with subsequent tissue necrosis. Activated and non-activated prothrombin complex concentrates were administered in the therapy of the haemorrhages. To eliminate factor VIII inhibitor, the patient was treated first with prednisone, then immunoglobulin G and finally with a combination of prednisone and cycylophosphamide, without any effect. A total spontaneous remission was observed after 15 months from the beginning of the disease.