Acquired hemophilia following COVID‐19 vaccination: Case report and review of literature

BACKGROUND: Acquired hemophilia A (AHA) is a rare bleeding disorder that can lead to spontaneous hemorrhage or bleeding induced by invasive procedures or trauma. We describe a patient who presented with multiple hematomas and a relapse of bullous pemphigoid shortly after his first dose of Vaxzevria ChAdOx1‐S COVID‐19 vaccination. We reviewed literature for cases of AHA following COVID‐19 vaccination. KEY CLINICAL QUESTION: Can COVID‐19 vaccines induce (a recurrence of) AHA? CLINICAL APPROACH AND CONCLUSIONS: The diagnosis of AHA with a relapse of bullous pemphigoid was made. The patient was treated with recombinant activated factor VII, emicizumab, rituximab, and methylprednisolone. There were no further bleeding events. However, the patient deteriorated because of sepsis and died on the fifteenth day of admission. CONCLUSION: Vaccines may trigger autoimmune events such as AHA. However, proof of causality is not possible and in this case the relapse of bullous pemphigoid before vaccination challenges this even more.