Phlyctenular Keratoconjunctivitis (Phlyctenular Conjunctivitis; Phlyctenulosis) By Melvin I Roat, MD, FACS, Sidney Kimmel Medical College at Thomas Jefferson University Reviewed / Revised Aug 2022 | Modified Sep 2022 View Patient Education Phlyctenular keratoconjunctivitis, a hypersensitivity reaction of the cornea and conjunctiva to bacterial antigens, is characterized by discrete nodular areas of corneal or conjunctival inflammation.