Neisseria sicca: A Rare Cause of Bacterial Conjunctivitis

BACKGROUND Neisseria-associated conjunctivitis is a rare cause of bacterial conjunctivitis in adults, with Neisseria gonorrhoeae as the primarily identified infectious strain. Here, we present a rare case of bacterial conjunctivitis due to Neisseria sicca in a 34-year-old immunocompetent man with no prior medical or ocular history. CASE REPORT A 34-year-old man with no significant past medical or ocular history presented with a 3-day history of left periorbital edema, ocular pain, and copious purulent discharge. Bacterial conjunctivitis was suspected due to the rapidity of onset and purulence. Peripheral corneal thinning was identified. Preliminary culture results showed gram-negative diplococci, and the patient was treated for gonococcal infection. Final cultures identified Neisseria sicca, a rarely pathogenic strain of Neisseria species. CONCLUSIONS This is the second reported case of Neisseria sicca-associated conjunctivitis, and the first reported case to have corneal involvement. Neisseria sicca, while typically non-pathogenic, may manifest as conjunctivitis in immunocompetent hosts with a low-risk sexual history.