Autoimmune blistering dermatoses as systemic diseases.

Autoimmune blistering dermatoses are examples of skin-specific autoimmune disorders that can sometimes represent the cutaneous manifestation of a multiorgan disease due to potential common pathogenic mechanisms. As soon as a distinct autoimmune blistering dermatosis is diagnosed, it is imperative to consider its potential systemic involvement, as well as the autoimmune and inflammatory conditions that are frequently associated with it. In paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome, the internal organs (particularly the lungs) are affected by the autoimmune injury. Pemphigus erythematosus may manifest with overlapping serologic and immunohistologic features of lupus erythematosus. In patients with bullous pemphigoid, there is a greater prevalence of neurologic disease, possibly caused by cross-reactivity of the autoantibodies with isoforms of bullous pemphigoid antigens expressed in the skin and brain. Anti-laminin 332 pemphigoid shows an increased risk for adenocarcinomas. Patients with anti-p200 pemphigoid often suffer from psoriasis. A rare form of pemphigoid with antibodies against the α5 chain of type IV collagen is characterized by underlying nephropathia. Particularly interesting is the association of linear IgA disease or epidermolysis bullosa acquisita with inflammatory bowel disease. Dermatitis herpetiformis is currently regarded as the skin manifestation of gluten sensitivity. Bullous systemic lupus erythematosus is part of the clinical spectrum of systemic lupus erythematosus, a prototypic autoimmune disease with multisystem involvement.