Case Report of a Novel Association between Anti-p200 Pemphigoid and Acquired Haemophilia A.

Anti-p200 pemphigoid is an uncommon subepidermal autoimmune bullous disease that, unlike many other autoimmune bullous diseases, has not previously been associated with hematological diseases. The diagnosis of anti-p200 pemphigoid in a patient with congruent clinical features requires the demonstration of subepidermal blistering, with linear deposition of immunoglobulin (Ig) G and/or C3 at the dermoepidermal junction on direct immunofluorescence, and a floor-binding pattern on indirect immunofluorescence. In addition, the detection of antibodies against p200 antigen via immunoblotting is ideal but not readily accessible in many facilities, leading to a potential under-recognition and under-diagnosis of this condition. In this case report, we describe a 53-year-old gentleman with recently diagnosed acquired hemophilia A who developed a concurrent vesiculobullous eruption and was evaluated to have anti-p200 pemphigoid. Both of his conditions were controlled with immunosuppression via prednisolone and cyclophosphamide. While we acknowledge the contemporaneous occurrence of both diseases in this patient may be a mere coincidence, it is important to recognize the possibility of this association given the potential clinical significance. Whether the activity of one disease parallels the other will require further evaluation.