A Case of Acquired Hemophilia A Following SARS-CoV-2 Infection.

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by antibodies against coagulation factor VIII. The majority of AHA cases are reported in an elderly population with chronic co-morbidities but can also be associated with other conditions, drugs, infections, and pregnancy. AHA is likely under-diagnosed and often unrecognized due to limited data about incidence, diagnosis, and management. We report a patient with no significant medical history who developed spontaneous ecchymoses and hematomas after a recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection complicated by a pulmonary embolism. These skin manifestations were initially thought to be related to the use of the direct oral anticoagulant apixaban, but further investigation revealed the presence of factor VIII inhibitors confirming the diagnosis of AHA. The patient was treated with prednisone and cyclophosphamide to eradicate the inhibitors with excellent response. Literature review shows a few cases of AHA after coronavirus disease 2019 (COVID-19) vaccination, H1N1 vaccination, and two cases after COVID-19 infection.

Parvovirus-Induced Transient Aplastic Crisis in a Patient With Newly Diagnosed Hereditary Spherocytosis.

Parvovirus B19 infections are prevalent in children and commonly present as slapped cheek fever, also known as the fifth disease. They are seen frequently in daycares and professions that require close contact with children. The most common presentation is a rash that is prominent on the cheeks; less common symptoms include painful or swollen joints (polyarthopathy syndrome). The infection is self-limited and resolves within one to two weeks. The virus has an affinity to the red blood cell (RBC) precursors and can rarely cause temporary cessation of the bone marrow's RBC production, leading to aplastic anemia. This is especially of significance in patients predisposed to increased RBC destruction, such as hereditary spherocytosis, sickle cell anemia, and other morphological abnormalities of the RBC. The overlapping arrest of RBC production and excessive destruction leads to a transient aplastic crisis (TAC), leading to severe life-threatening anemia, requiring blood urgent blood transfusions. There have been many studies reporting the incidence of TAC in patients with sickle cell crisis. Only a few cases have been reported in patients with hereditary spherocytosis.