Acquired hemophilia A is a rare condition characterized by de novo
development of a coagulation factor VIII inhibitor. Inhibition of factor
VIII activity results in increased susceptibility to bleeding events,
most frequently mucosal or soft tissue bleeding. We report two cases of
acquired hemophilia A in previously healthy pediatric patients. Notably,
both patients presented with hemarthrosis as the sentinel bleeding
event. In both cases, administration of immunosuppressive therapy was
associated with inhibitor loss and patient cure. These cases emphasize
the importance of considering acquired hemophilia A in pediatric
patients presenting with acute onset hemarthrosis.