Therapeutic approaches and targets for treatment of autoimmune bullous diseases

Autoimmune bullous diseases are a heterogeneous group of diseases characterized by the development of cutaneous and mucosal vesicles, blisters, and finally erosions. The common pathogenetic mechanism is the presence of autoantibodies targeting structural proteins of the skin and mucous membranes (demosomes and hemidesmosomes): in the case of pemphigus, the antigens are intraepidermal, whereas in the case of pemphigoid, dermatitis herpetiformis, and epidermolysis bullosa acquisita they are subepidermal. Mucosal involvement typically affects the oral and ocular mucosa, but in some cases, the upper airways or the upper digestive tract are affected. The burden on patients' lives could be severe due to the impairment of normal feeding or breathing. In other cases, they may represent paraneoplastic syndromes. Since autoimmune bullous diseases may result in significant morbidity and mortality, depending on the grade of cutaneous and mucosal involvement, a prompt therapeutic approach is mandatory and, in recalcitrant cases, may be challenging. The first line therapy consists of corticosteroids, both topical and systemic. Once remission or control of the acute phase is obtained, adjuvant therapies need to be introduced in order to spare the corticosteroid load and minimize side effects such as iatrogenic diabetes or osteoporosis. Herein, we describe all current therapeutic approaches to autoimmune bullous diseases, also including emerging therapies.