CONJUNCTIVITIS

Conjunctivitis refers to any inflammatory condition of the membrane th at lines the eyelids and covers the exposed surface of the sclera. It is the most common cause of ''red eye.'' The etiology can usually be d etermined by a careful history and an ocular examination, but culture is occasionally necessary to establish the diagnosis or to guide thera py. Conjunctivitis is commonly caused by bacteria and viruses. Neisser ia infection should be suspected when severe, bilateral, purulent conj unctivitis is present in a sexually active adult or in a neonate three to five days postpartum. Conjunctivitis caused by Chlamydia trachomat is oz Neisseria gonorrhoeae requires aggressive antibiotic therapy but conjunctivitis due to other bacteria is usually self-limited. Chronic conjunctivitis is usually associated with blepharitis, recurrent stye s or meibomianitis. Treatment requires good eyelid hygiene and the app lication of topical antibiotics as determined bu culture. Allergic con junctivitis is distinguished by severe itching and allergen exposure. This condition is generally treated with topical antihistamines, mast- cell stabilizers or anti-inflammatory agents.