Case Presentation: A 78-year-old female was referred to the ED from clinic for elevated creatinine and hyperkalemia after recent treatment of right lower extremity cellulitis with sulfamethoxazole/trimethoprim. Physical exam showed improving cellulitis and large area of ecchymosis on right wrist. The patient reports developing frequent large bruises without trauma for the previous two months. During hospitalization, the patient had repeated drops in hemoglobin below transfusion thresholds without any obvious source of bleeding. The patient was transfused to maintain hemoglobin greater than 7mg/dL. The patient developed diffuse ecchymosis on her abdominal flank for which CT abdomen showed a large retroperitoneal hematoma. Workup for continued bleeding included platelets of 360, INR 1.2, PT 14.9, and aPTT 101. A mixing study was obtained for elevated aPTT and was suggestive of an inhibitor to factor VIII. Acquired hemophilia A (AHA) was confirmed on subsequent testing. The patient received multiple doses of activated Factor VII as a by-pass medication for frequent active bleeding episodes. Bethesda units of 127 demonstrated severe autoimmune inhibition. Cyclophosphamide and prednisone were started for immunosuppression. The patient required multiple hospitalizations for recurrent bleeding. She ultimately did not respond to immunosuppression and passed 44 days after initial presentation.
Discussion: AHA is a rare and potentially life-threatening bleeding disorder caused by the accumulation of autoantibodies against factor VIII. The creation of these antibodies has several documented causes including pregnancy, autoimmune diseases, malignant neoplasms, and allergic reaction to certain medication. Generally, cessation of the offending agent leads to clearing of drug-induced antibodies [1]. However, according to the EACH2 database, around half of the patients with AHA have no identifiable cause [2]. The median age at diagnosis is 73.9 years, much older than its congenital counterpart. Unlike congenital hemophilia A, it is rare for AHA to bleed into joint spaces, rather bleeding occurs in the skin, muscles, soft tissues, and mucous membranes [1]. Due to its rarity, delays in diagnosis may contribute to the mortality rate of AHA which can be as high as 42% [3].
Conclusions: We present a case of acquired hemophilia A, a rare bleeding disorder with incidence of 1.5 per million per year [4]. Although this case included treatment with sulfonamides, cessation of the sulfonamide did not resolve the bleeding diathesis. It is felt that this case likely represents an idiopathic etiology. Finally, early recognition and timing of symptom onset assisted with early diagnosis in this patient but ultimately still proved fatal. Prompt recognition of symptoms, early confirmatory testing, and implementation of bypassing agents (e.g. recombinant activated factor VII) and immunosuppression agents (e.g. cyclophosphamide and prednisone) are vital for patient survival.