 The specific goal is to describe in each patient with bullous pemphigoid the therapeutic management, including: i all topical and systemic medications and nursing cares; ii clinical and biological monitoring and iii clinical outcome during the first year of treatment. The hypothesis to be answered by the study is that topical superpotent corticosteroid therapy is properly used to treat bullous pemphigoid in real-world life as recommended by French guidelines and whether this treatment influences the medical costs by comparison with systemic therapies e.g. methotrexate or prednisone. 