Acquired epidermolysis bullosa is a rare severe systemic disease of the skin and mucosa where the etiopathogenetic role is played by circulating IgG autoantibodies. To make its diagnosis, to use adequate therapy, and to define management tactics in patients with this pathology require that specialists should have high qualification and knowledge of the manifestations and course of autoimmune bullous dermatoses. The paper presents a case of acquired epidermolysis bullosa of mixed genesis with the involvement of IgG/IgA autoantibodies, which mimics the clinical picture of pemphigus vulgaris torpidly running during immunosuppressive therapy. By considering the etiopathogenesis, the authors emphasize the important role of immunofluorescence in the diagnosis and differential diagnosis of autoimmune bullous dermatoses.