Case Presentation: Acquired Hemophilia A (AHA) is a rare disease, with 1 to 2 cases per million, and occurs due to production of autoantibodies that inhibit Factor VIII, a vital step of the intrinsic coagulation cascade, resulting in the potential for lethal bleeding. Here we present a case of a 59-year-old woman with history of irritable bowel syndrome and shingles flare on her right face 3 months prior who presented to the emergency room with new onset ecchymoses and swelling of her left arm with concern for deep vein thrombosis. Similar, but milder, symptoms in her right arm resolved earlier that week. She also complained of arthralgias in her left elbow, wrist and metacarpophalangeal joints, but denied fevers, chills or trauma.On exam, her vital signs were within normal limits. There were several unilateral, painful, subcutaneous nodular lesions amid areas of ecchymosis on her lateral arm and medial forearm. Her joints were tender to palpation on the left upper extremity, but without effusions. The remainder of the examination was unremarkable, except for the development of similar subcutaneous nodular lesions on her left leg over the next two days. Initial studies were remarkable for mild anemia, an elevated activated partial thromboplastin time (aPTT) and mild elevation in creatine kinase. Other coagulation studies, platelet count and a comprehensive metabolic panel were normal. A doppler ultrasound was negative for DVT and magnetic resonance imaging revealed non-specific soft tissue swelling. Her initial presentation and work-up generated a large differential including coagulopathic disorders, vasculitis, rheumatologic disorders and occult lymphoma/malignancy. In consultation with rheumatology, a broad autoimmune panel/workup was sent that was unrevealing, and a biopsy of the subcutaneous nodule was performed which showed non-descript myositis and localized hematomas. Given the elevated aPTT, clotting factor levels were sent demonstrating a severe FVIII deficiency. Mixing studies were performed without improvement in aPTT suggesting the presence of a FVIII inhibitor. A Bethesda assay revealed an inhibitor concentration of 5.6 Bethesda units. After establishing the diagnosis of AHA, she underwent factor replacement with recombinant FVIII and immunosuppression with prednisone leading to resolution of her ecchymosis and recovery of her aPTT and FVIII levels. She proceeded to undergo further evaluation for potential triggers for AHA, however, autoimmune, rheumatologic and malignancy work-up were negative.

Discussion: This case of AHA highlights the importance of maintaining a broad and stepwise approach to a patient with a bleeding disorder, as AHA is frequently underdiagnosed and misdiagnosed. We also hope to highlight the importance of considering AHA in patients with similar symptoms to aid in early recognition and treatment, which is fundamental as delays can be associated with adverse outcomes.

Conclusions: It is vital to maintain a high index of suspicion for AHA when patients present with bleeding complications, as AHA can be triggered by a number of stimuli and is associated with a high risk of life-threatening bleeding. In the case presented here the most likely trigger was the a recent Herpes Zoster flare. Recent reviews have shown that management with steroids alone results in similar outcomes to concurrent treatment with cytotoxic immunosuppressants. Recurrence rates can be as high as 20% so it is important for patients to be aware of this condition and inform future healthcare providers.

IMAGE 1: Figure 1. Ecchymosis on medial left extremity and resolving ecchymosis of right extremity.

IMAGE 2: Figure 2. Firm subcutaneous nodule within area of evolving ecchymosis