Case Presentation: A 70-year-old African American woman with a past medical history of hypertension, Type II diabetes mellitus, and COPD presented to the emergency department complaining of new-onset right arm bruising and swelling with no history of trauma. The patient had been recently hospitalized a week prior for a chest pain workup that was negative. Physical exam revealed the right forearm was significantly ecchymotic and tender, bruising also present in the left knee, left thigh, in addition to areas of bruising where she had received her enoxaparin injections in her prior hospitalization. Vital signs at the time of admission were stable. Arterial and venous duplex of the right upper extremity was negative for evidence of thrombosis or stenosis. The initial coagulation profile revealed a prolonged isolated APTT (activated partial thromboplastin time) at 124.2s (reference range: 28.5-38s) in the setting of a normal PT/INR. At the time of admission, her complete blood count was as follows: hemoglobin 10 g/dL, white blood cell count 14.5 x 10⁹/L, platelet count 379 x 10⁹/L.Further studies revealed that the prolonged aPTT failed to correct via mixing with normal plasma and a severely depressed FVIII Activity of 2% (reference range: 50-150%), indicating the presence of a factor VIII inhibitor. Connective tissue disorder workup was negative with an antinuclear antibody titer was nonspecific at 1:80 and a negative rheumatoid factor. She was started on Intravenous Immunoglobulin (1g/kg/d) to reverse the coagulopathy and prednisone 80mg daily (1mg/kg/d) for immunosuppression. On hospital day 3, however, the patient developed an acute hypoxic respiratory failure and suffered a PEA arrest, leading to anoxic brain injury.

Discussion: Acquired inhibitors against Factor VIII is also known as acquired hemophilia A (AHA) that is a rare bleeding condition with a reported incidence of 1.5 cases/million/year, caused by the development of autoantibodies associated with a high rate of morbidity and mortality with severe bleeds reported to occur in up to 90% of affected patients and mortality rate ranging 8-22% [1,3]. Unlike its congenital counterpart of classic presentation of hemarthroses, the bleeding pattern in the acquired form can vary in severity and manifestations. Patients will often bleed at multiple sites, including soft tissues, muscles, skin, and mucous membranes [2,4].

Conclusions: The diagnosis of acquired hemophilia A can be challenging, attributed to its rarity and the absence of personal or family history of bleeding diathesis and heterogeneous clinical manifestations.