As discussed previously, most papillary conjunctivitis, some forms of granulomatous conjunctivitis, and toxic follicular conjunctivitis are associated with noninfectious etiologies. See the sections Papillary Versus Follicular Conjunctivitis and Granulomatous Conjunctivitis for specific examples.
Ocular cicatricial pemphigoid (OCP) is a form of cicatrizing conjunctivitis that is of autoimmune etiology. It typically also involves other mucous membranes and sometimes involves the skin. When this diagnosis is suspected clinically, conjunctival biopsy is performed to establish the diagnosis. Half of the specimen should be submitted in formalin for routine histology, and half submitted in Michel medium or saline for immunofluorescence analysis. Histology shows bullae of the epithelium and a subepithelial band of chronic inflammatory cells, predominantly plasma cells (Fig 5-9). Immunofluorescence demonstrates IgG, IgM, and/or IgA immunoglobulins, and/or complement (C3) positivity in the epithelial basement membrane zone. The clinician must bear in mind that the sensitivity of immunofluorescence may be as low as 50% (particularly in long-standing cases with severe cicatrization). Thus, a negative result does not rule out the possibility of OCP. See also BCSC Section 8, External Disease and Cornea.