[Autoimmune bullous disease and Hashimoto's disease complicated by acquired hemophilia A].

A 67-year-old man was admitted with a 1-month history of spontaneous hematoma in his right back and severe anemia. He had suffered from rashes with blisters involving both legs for 10 years, which had shown worsening and extended to his entire body concurrently with the hematoma. APTT was markedly prolonged to 119 seconds, and Factor VIII:C and FVIII inhibitor levels were less than 1% and 153.1 BU/ml, respectively, confirming the diagnosis of acquired hemophilia A (AHA). Skin biopsy revealed his rashes to be caused by autoimmune bullous disease (ABD), and laboratory and physical findings showed that he also had autoimmune hypothyroidism (Hashimoto's disease). Recombinant FVIIa was effective for management of his bleeding; in addition, FVIII inhibitor reduction and FVIII:C recovery, in parallel with improvement of the skin lesions, were achieved by administering prednisolone and cyclophosphamide. To our knowledge, this is the first report of AHA associated with ABD and Hashimoto's disease.