Drug-induced cicatricial pemphigoid affecting the conjunctiva. Light and electron microscopic features

Cicatricial pemphigoid (CP) is a chronic inflammatory disease which can affect the conjunctiva. It is a slowly progressive disorder of unknown but presumed autoimmune etiology. Pseudopemphigoid, or CP associated with ocular drug administration, has also been described. These cases, which appear clinically indistinguishable from unilateral idiopathic CP affecting the conjunctiva, have been related to the use of echothiophate iodide, pilocarpine, idoxuridine, and epinephrine. We report the histopathologic and ultrastructural characteristics of 22 biopsies from ten patients with iatrogenic CP following the use of various ocular drugs. All patients presented with clinically obvious, active CP affecting the conjunctiva. Light microscopy and electron microscopy revealed findings identical to those previously reported for idiopathic CP of the conjunctiva: squamous metaplasia, increased numbers of desmosomes, basal lamina modifications suggestive of damage and attempted repair, subepithelial inflammatory cell infiltration, and diminished intravascular space within the stroma. These patients responded to immunosuppressive therapy. The authors wonder if it is possible that these patients were destined to develop CP, but that with topical ocular drug use, a more rapid emergence of the chronic cicatrizing feature of CP developed.