Diagnostic and Treatment Challenges for Acquired Hemophilia A in Pediatrics: Report of 2 Cases.

Acquired hemophilia A (AHA) occurs rarely in children. We report 2 cases of adolescent females with AHA. The first case underwent bone marrow aspiration/biopsy during workup, which was complicated by bleeding. Bleeding resolved after initiation of therapy with cyclophosphamide and glucocorticoid, but despite the addition of rituximab, she did not achieve complete remission until treatment with intravenous immunoglobulin. In the second case, we observed that a mixing study without incubation will not detect an acquired factor VIII inhibitor, but further workup based on suspicion for AHA led to the correct diagnosis. Both had significant medication toxicity which required treatment modification.