Acquired hemophilia.

Acquired hemophilia (AH) is an autoimmune hemostatic disorder mediated by autoantibodies directed against factor VIII: C. In 52% of cases, the cause is unknown or is not associated with other pathological entities; in the rest, there are concomitant factors: lupus, rheumatoid arthritis, cancer, pregnancy, and medications. In Mexico, there is not a registry of AH, and awareness of the disease among health personnel is low. The groups with the highest incidence are women of childbearing age and individuals older than 70 years. It is characterized by severe bleeding, especially after trauma and normal childbirth or cesarean delivery, and large ecchymoses in the trunk and extremities. The suspicion is simple, it just takes for sudden, severe hemorrhage and a prolonged activated partial thromboplastin time that is not corrected with plasma to concur in an individual. Treatment involves achieving hemostasis and eradicating the antibody. The former is achieved with recombinant activated factor VII or activated prothrombin complex concentrate. Cyclophosphamide, prednisone or rituximab are used to eradicate the antibody. Most cases of AH are not diagnosed, which translates into a high mortality rate. Given that awareness about the disease among physicians is low, it is not suspected, neither diagnosed, and nor is it treated. This document reviews the most recent data on AH and expands on its diagnosis and treatment.