Progressive Intramuscular Haematoma in a 12-Year-Old Boy: A Case of Acquired Haemophilia A

Acquired hemophilia A (AHA) is a rare bleeding disorder due to acquired antibodies against coagulation factor VIII (FVIII). It is rare in children less than 16 years old, and the incidence is 0.45/million/year. An otherwise healthy, 12-year-old boy was admitted to the ward with a history of swelling of the right and left forearms, for 1 day duration. He did not have any history of trauma or bleeding disorder. He had prolonged APPTT level with very high antibody titer against factor VIII. His gene expression for factor VIII was found to be normal. He was managed with FEIBA and recombinant FVII activated complexes and prednisolone 1 m/kg/day regime to control bleeding. AHA is associated with several underlying pathologies such as pregnancy, autoimmune diseases, malignancy, medications and infections; however, up to 50% of reported cases are idiopathic. In contrast to congenital haemophilia A, in which haemarthrosis is the hallmark clinical presentation, patients with AHA mainly bleed in to the skin, muscles, and soft tissues. High mortality rate of more than 20% is either to retroperitoneal or intracranial bleeds. Diagnosis is confirmed on isolated prolongation of activated partial thromboplastin time which does not normalize after addition of normal plasma, reducing the factor VIII levels with evidence of FVIII inhibitor activity. They have normal prothrombin time and platelet functions. Management of AHA involves two aspects, namely, eradication of antibodies and maintaining effective haemostasis during a bleeding episode.