Abstract
RATIONALE: Acquired hemophilia A (AHA) is a rare but life-threatening bleeding disorder, necessitating enhanced recognition in patients with concomitant autoimmune diseases. PATIENT CONCERNS: A 91-year-old female with bullous pemphigoid presented with spontaneous subcutaneous bleeding and prolonged activated partial thromboplastin time. DIAGNOSES: Laboratory investigations revealed a decrease in factor VIII activity to 6.4%, confirming the diagnosis of bullous pemphigoid-associated AHA. INTERVENTIONS: The patient was subjected to monotherapy with glucocorticoids and supportive hemostatic measures. OUTCOMES: Coagulation parameters normalized within 1 month, and no severe complications occurred. LESSONS: This case highlights the importance of considering AHA in elderly patients with autoimmune diseases who present with unexplained bleeding. An individualized treatment strategy may improve clinical outcomes.