Abstract

Acquired Hemophilia A is a very rare disease in children but may be life-threatening. We report the case of a 5-year-old child, without any bleeding history. He presented a severe bleeding episode after a circumcision. The blood loss was important, with a hemoglobin rate at 54g/L, requiring a transfusion. The first biological assessment of hemostasis lead to the suspected diagnosis of congenital hemophilia (FVIII=4%), but factor VIII infusions were inefficient. Identification of a specific inhibitor against factor VIII rectified the diagnosis: it was an acquired hemophilia A. No underlying infectious, autoimmune or neoplastic disease was found. Interestingly, he has family history of immune disease: his brother has a juvenile arthritis and his father a Sjogren syndrome.

Clinical evolution was favorable after treatment by recombinant activated factor VII (Novoseven®). Afterwards, he has two bleeding episodes: a large post-venous puncture hematoma, and a post-traumatic hemarthrosis of the knee, efficiently treated by Novoseven®. An immunosuppressive treatment started then: he received a first line therapy of corticoids without any effect on the inhibitor level. A second line therapy with rituximab was attempted, with a greater efficacy. The inhibitor level is now below 1 BU/ml, and the factor VIII level is 120%. This case highlights the difficulties of diagnosing acquired hemophilia A in childhood. Due to its rarity, this condition was first not recognized. Concerning immunosuppressive therapy, this case is the second case of the pediatric literature in this indication that proves efficacy of rituximab.

Keywords: Acquired hemophilia A; Childhood; Rituximab; Post-operative hemorrhage; Hemarthrosis; Diagnosis