Association of bullous pemphigoid with acquired hemophilia A: a case report.

Acquired hemophilia A, a rare condition resulting in spontaneous bleeding without prior bleeding disorders, arises due to autoantibody-mediated inhibition of coagulation factor VIII and is typically associated with autoimmune, neoplastic, drug, or obstetric factors. We present the case of a 31-year-old woman with bullous pemphigoid, managed with corticosteroids since 2013, who presented spontaneous hemorrhagic manifestations. Upon admission, laboratory tests revealed hypochromic microcytic anemia, prolonged activated partial thromboplastin time, and a factor VIII level < 1%, indicative of acquired hemophilia A. Further assessments showed elevated Ristocetin cofactor activity, von Willebrand factor antigen, and a factor VIII inhibitor level of 665 BU. This underscores the importance of considering acquired hemophilia A in autoimmune dermatological conditions like bullous pemphigoid, highlighting the association between autoimmune disorders and coagulation abnormalities, particularly in cases of spontaneous hemorrhagic events.