Ocular and oral mucous membrane pemphigoid (cicatricial pemphigoid).

Mucous membrane pemphigoid, a heterogeneous group of autoimmune blistering diseases, affects primarily the mucous membranes. Although oral and ocular mucosae can both be affected in a given patient, patients with involvement restricted to oral mucosae tend to have a benign outcome, whereas those with ocular disease commonly face treatment resistance, resulting in scarring and blindness. Diagnosis requires direct immunofluorescence microscopy to demonstrate a linear deposition of immunoglobulin (Ig) G or IgA, or complement component 3 (C3), at the epithelial basement membrane. Although the target antigens vary, subsets of patients affected exclusively by oral and ocular mucosal diseases have autoantibodies targeting α-6 and β-4 integrins, respectively.