- Phlyctenular keratoconjunctivitis,is an inflammatory syndrome caused by a delayed type-IV hypersensitivity reaction to one or more antigens.
- The triggering antigen is usually a bacterial protein (most common – Staphylococcus aureus).
- These usually manifest as small raised nodules, pinkish-white or yellow in color, which may ulcerate (or, more rarely, necrose) and are often surrounded by dilated blood vessels.
- Corneal lesions are usually triangular in shape, with the base at the limbus and the apex pointing towards the center of the cornea.
Characterized by the following:
o May eventually form ring ulcers
o Scrofulous ulcer: shallow marginal ulcer due to the breakdown of limbal phlycten
o Fascicular ulcer has a prominent parallel leash of blood vessels. It heals leaving a band-shaped opacity.
- Topical steroids; atropine if the cornea is involved.