Isolated conjunctival lichen planus: a diagnostic challenge.

BACKGROUND: Lichen planus is a common inflammatory autoimmune condition of unknown etiology that commonly affects the skin and mucous membranes. Isolated ocular lichen planus is an extremely rare presentation that most commonly involves the eyelids, conjunctiva, and cornea, leading to severe scarring, and is clinically indistinguishable from other causes of cicatricial conjunctivitis. OBSERVATIONS: A 79-year-old man complained of a chronic keratoconjunctivitis refractory to multiple topical treatments. Slit-lamp examination revealed diffuse bilateral conjunctival hyperemia, subepithelial fibrosis, and symblepharon, with a marked shortening of the lower conjunctival fornix. There were no other skin or mucosal lesions. Hematoxylin-eosin staining revealed acanthosis, focal thickening of the basement membrane, and a dense subepithelial mononuclear infiltrate. Direct immunofluorescence demonstrated a linear shaggy fibrinogen deposition along the basement membrane, suggestive of lichen planus. Ultrastructural examination revealed a marked widening of the epithelium-lamina propria interphase, with prominent fragmentation, reduplication, and reticulation of the lamina densa of the basement membrane. The patient was successfully treated with systemic immunosuppressive agents.
CONCLUSIONS: Isolated conjunctival lichen planus is an exceptional and severe cause of cicatricial conjunctivitis. Distinguishing this unusual presentation from other inflammatory diseases with conjunctival involvement is crucial to initiate an appropriate therapy early to avoid irreversible damage of the visual function.