Pemphigus family of diseases

Pemphigus is a group of autoimmune blistering diseases of the skin and mucous membranes, which are mediated by immunoglobulin G (IgG) autoantibodies against the cadherin type of cell-cell adhesion molecules in desmosomes, desmogleins. Pemphigus is histologically characterized by acantholysis, that is, intraepidermal blisters due to the loss of cell-cell adhesion of keratinocytes, and immunopathologically by the finding of in-vivo-bound and circulating IgG autoantibodies directed against the cell surface of keratinocytes. Pemphigus has three major forms: pemphigus vulgaris, pemphigus foliaceus, and paraneoplastic pemphigus. Pemphigus vegetans is a variant of pemphigus vulgaris. Pemphigus erythematosus is a localized variant of pemphigus foliaceus, and fogo selvagem is an endemic variant of pemphigus foliaceus. Patients with pemphigus vulgaris and pemphigus foliaceus have IgG autoantibodies against desmoglein 3 and desmoglein 1, respectively, while patients with paraneoplastic pemphigus have IgG autoantibodies against plakin molecules in addition to desmogleins. Systemic corticosteroids are the mainstay of therapy for pemphigus, and adjuvant therapies, including immunosuppressive agents, plasmapheresis, and high-dose intravenous immunoglobulin, are used for severe cases.