[Subepidermal bullous autoimmune dermatosis with linear deposition of IgA amd IgG]

A 29-year-old female patient with an autoimmune subepidermal blistering disease had linear deposits of both IgA and IgG at the basement membrane zone. Clinically, the patient presented with tense blisters on the face, trunk, extremities and oral mucosa. Histologically, we found a subepidermal blister formation and a predominantly neutrophilic infiltrate. Direct immunofluorescence showed linear deposits of IgA along the basement membrane zone, as well as linear deposits of IgG and C3 as typically found in bullous pemphigoid. Indirect immunofluorescence demonstrated circulating IgA and IgG autoantibodies. This case extends previous reports on a subgroup of patients with subepidermal blistering diseases characterized by the presence of both IgA and IgG anti-basement membrane antibodies. These patients reveal clinical, histological and immunopathological features of linear IgA disease and bullous pemphigoid.