Abstract
An 82-year old man was admitted for abnormal bleeding following traumatic injury. He has been suffering from psoriasis since 40 years ago. Laboratory findings included PT at <5%, APTT at >200 sec, factor V activity (FV : C) of <3%, and factor V inhibitor of 7 BU/ml. The diagnosis of acquired factor V inhibitor was made. When he received fresh-frozen plasma, his clinical bleeding disappeared. FV : C was then increased very slowly, and his factor V inhibitor was slightly reduced without any treatment. After 11 months at the onset, he had melena and cerebral infarction. Laboratory findings showed the decrease in FV : C (7.8%) and the increase in factor V inhibitor (2.1BU/ml). The patient was treated with prednisolone. Within 14 days after the treatment, the FV : C was increased to the normal level and factor V inhibitor was disappeared, suggesting a very good response to corticosteroid.
